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Mass Transport: Circulatory System with Emphasis on Nonendothermic Species

Dane A. Crossley, Warren W. Burggren, Carl L. Reiber, Jordi Altimiras, Kenneth J. Rodnick

10.1002/cphy.c150010

Source: Volume 7, Issue 1, January 2017

Published online: December 2016

Full Article on Wiley Online Library



ABSTRACT

Mass transport can be generally defined as movement of material matter. The circulatory system then is a biological example given its role in the movement in transporting gases, nutrients, wastes, and chemical signals. Comparative physiology has a long history of providing new insights and advancing our understanding of circulatory mass transport across a wide array of circulatory systems. Here we focus on circulatory function of nonmodel species. Invertebrates possess diverse convection systems; that at the most complex generate pressures and perform at a level comparable to vertebrates. Many invertebrates actively modulate cardiovascular function using neuronal, neurohormonal, and skeletal muscle activity. In vertebrates, our understanding of cardiac morphology, cardiomyocyte function, and contractile protein regulation by Ca2+ highlights a high degree of conservation, but differences between species exist and are coupled to variable environments and body temperatures. Key regulators of vertebrate cardiac function and systemic blood pressure include the autonomic nervous system, hormones, and ventricular filling. Further chemical factors regulating cardiovascular function include adenosine, natriuretic peptides, arginine vasotocin, endothelin 1, bradykinin, histamine, nitric oxide, and hydrogen sulfide, to name but a few. Diverse vascular morphologies and the regulation of blood flow in the coronary and cerebral circulations are also apparent in nonmammalian species. Dynamic adjustments of cardiovascular function are associated with exercise on land, flying at high altitude, prolonged dives by marine mammals, and unique morphology, such as the giraffe. Future studies should address limits of gas exchange and convective transport, the evolution of high arterial pressure across diverse taxa, and the importance of the cardiovascular system adaptations to extreme environments. © 2017 American Physiological Society. Compr Physiol 7:17‐66, 2017.

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Figure 1. Figure 1. A conceptual view of the relationship between resting oxygen (O2) consumption and body size, establishing two “zones.” In the zone to the lower left below the dashed line, simple diffusion of gases, nutrients, and wastes is adequate for either very small organisms (e.g., protists and worms) or the exceptional larger, but relative inactive animals (flatworms). In the upper right zone, internal blood convection is required for larger animals (vertebrates) or the exceptional very active smaller animals (e.g., Daphnia).
Figure 2. Figure 2. A model for pressure/flow stimulation of angiogenesis in the early vertebrate embryo. Panel A shows the hemodynamic factors of flow‐ and pressure‐generating cyclic and shear stress on the endothelium‐lined walls of the vasculature. Panel B shows the response of individual endothelial cells to hemodynamically generated stressors. Secretion of VEGF through a paracrine effect stimulates division of adjacent endothelial cells. Adapted, with permission, from (83).
Figure 3. Figure 3. The relationship between embryo size (as radius) at the onset of convective blood flow (ronset) and the calculated maximum embryo radius at which diffusion can serve O2 uptake needs (rmax). Four vertebrate classes with highly varying rates of O2 consumption are represented. The “synchronotropy line” (dashed line) indicates the point in this interrelationship at which there is a perfect match between the onset of blood flow and the development of the need for blood flow for O2 transport. The solid line represents a regression through the plotted data points. See text and (80) for additional details of the calculations and their interpretation.
Figure 4. Figure 4. Endothelial vascular lining, blood pressure, and the major animal lineages. The appearance of a complete or incomplete endothelial vascular lining is shown, along with an indication of general blood pressures for each group. Downward arrow indicates low blood pressure; upward arrow indicates high blood pressure. Adapted, with permission, from (83).
Figure 5. Figure 5. Mechanisms of cardiac regulation. (A). Intrinsic cardiac regulation: The neurogenic decapod heart contracts in response to pacemaker cells associated with the cardiac ganglion located in or on the dorsal aspect of the heart. These interneurons synapse with larger motoneurons that innervate cardiac muscle fibers directly and through extensive dendritic ramifications control both rate and strength of cardiac contractions. Extrinsic cardiac regulation: The cardiac ganglion, myocardia, ostia, suspensory ligaments, and arterial valve are all under extrinsic neuronal and neurohormonal control. The rate and force of cardiac contraction are modulated through cardioregulatory nervous input to both the cardiac ganglion and myocardia. Through the thoracic ganglion (dorsal nerve) two pair of cardio accelerator nerves (SN III) and one pair of cardio inhibitor nerves (SN II) influence the rate of depolarization of the pacemaker cells in the cardiac ganglion and force of myocardia contraction. Neurohormonal control of cardiac function is through the pericardial organ (PO), which releases an array of cardioactive substances into the paricardial sinus in response to dorsal nerve input via the neuroregulatory fibers. (B) Cardiac contraction is initiated by the cardiac ganglion, resulting in the generation of tension and myocardial contraction. The myocardia is composed of a three‐dimensional array of fibers arranged around the lumen of the heart (B3) and forces hemolymph into multiple arterial systems through the arterial valves (B2). Both nervous regulate arterial and ostial valve tone and neurohormonal input to facilitate coordinated and functional contraction (B1). B1 adapted, with permission, from (6), B2 and B3 adapted, with permission, from (369).
Figure 6. Figure 6. The functional linkage between the actions of the cardiac ganglion and the generation of hemolymph pressure to drive blood through the circulatory system is myocardial contraction. The decapod (Procambarus clarkii) cardiac cycle begins with systole, isovolumic contraction (muscle fiber depolarization with the generation of pressure or tension) as seen by the rapid rise in intracardiac pressure which rapidly igoes from close to zero to approximately 1.33 kPa. A notch similar to the dicrotic notch seen in mammalian ventricular pressure profiles is observed as the multiple arterial valves open due to the ventricular‐arterial pressure difference. Intracardiac and arterial pressures equalize once the arterial valves are open and hemolymph is propelled out of the ventricle into the arteries during the ejection phase. Arterial pressures are maintained above intracardiac pressure once the arterial valves close and the heart goes into isovolumic relaxation. Arterial hemolymph pressure diminishes slowly due to the passive elastic properties of the major vessels leaving the heart. Diastole or ventricular filling occurs as the result of a pericardial‐intracardiac pressure difference. During diastole, pericardial pressure continues to increase as hemolymph moves from the infrabranchial sinus through the gills and into the pericardial region. Open ostial valves allow the pressure difference to drive hemolymph into the ventrical during the filling phase, which ends with onset of the next systolic contrition (478).
Figure 7. Figure 7. A comparative scheme of the sources of activator Ca2+ during excitation‐contraction coupling in mammalian (A) and teleost (B) ventricular myocytes. Both cardiomyocytes are approximately the same length, but the teleost cell is narrower, elliptical in cross section, lacks transverse tubules, has a less well‐developed SR, and has a much higher surface area to volume ratio. Contractile activity in all vertebrate hearts depends, in large part, on how much Ca2+ is delivered, to myofilaments. In the mammalian cardiomyocyte, activator Ca2+ comes from extracellular Ca2+ entering the cell through Ca2+ channels (DHPR, #1 and 2) and Na+/Ca2+ exchangers (reverse mode, #3) on the sarcolemma and transverse tubules (T tubules). Ca2+ influx also triggers Ca2+ release from the SR (intracellular Ca2+ store) by the RyR (#4). Relaxation occurs by SR Ca2+ pumps (SERCA, #6), sarcolemmal Ca2+ pumps (#7), and Na+/Ca2+ exchangers (#8). The primary source of Ca2+ for contraction in the teleost cardiomyocyte is extracellular with transsarcolemmal influx through Ca2+ channels (#1) or Na+/Ca2+ exchangers (#2) in reverse mode. Depending on the fish species and environmental conditions, SR Ca2+ may also be important (#4). For relaxation, teleosts rely on sarcolemmal Ca2+ pumps (#5), Na+/Ca2+ exchangers (#6), and possibly SR Ca2+ pumps (#7). Based on information in references (40, 528, 593). See text for additional details.
Figure 8. Figure 8. A list of known regulators of ventricular function during a cardiac cycle in vertebrates. Although blood is shown as red, reflecting complete oxygenation, the vertebrate ventricle may pump different degrees of oxygenated or deoxygenated blood. See text for details.
Figure 9. Figure 9. Summary of diving specializations in a generic seal species.
Figure 10. Figure 10. Summary of features aiding to high‐altitude flight in bar‐headed goose either as avian general traits (blue boxes) or species‐specific specializations (orange boxes). Reprinted from (509) with permission.
Figure 11. Figure 11. Summary of specializations to account for gravitational effects in the cardiovascular system of the giraffe.


Figure 1. A conceptual view of the relationship between resting oxygen (O2) consumption and body size, establishing two “zones.” In the zone to the lower left below the dashed line, simple diffusion of gases, nutrients, and wastes is adequate for either very small organisms (e.g., protists and worms) or the exceptional larger, but relative inactive animals (flatworms). In the upper right zone, internal blood convection is required for larger animals (vertebrates) or the exceptional very active smaller animals (e.g., Daphnia).


Figure 2. A model for pressure/flow stimulation of angiogenesis in the early vertebrate embryo. Panel A shows the hemodynamic factors of flow‐ and pressure‐generating cyclic and shear stress on the endothelium‐lined walls of the vasculature. Panel B shows the response of individual endothelial cells to hemodynamically generated stressors. Secretion of VEGF through a paracrine effect stimulates division of adjacent endothelial cells. Adapted, with permission, from (83).


Figure 3. The relationship between embryo size (as radius) at the onset of convective blood flow (ronset) and the calculated maximum embryo radius at which diffusion can serve O2 uptake needs (rmax). Four vertebrate classes with highly varying rates of O2 consumption are represented. The “synchronotropy line” (dashed line) indicates the point in this interrelationship at which there is a perfect match between the onset of blood flow and the development of the need for blood flow for O2 transport. The solid line represents a regression through the plotted data points. See text and (80) for additional details of the calculations and their interpretation.


Figure 4. Endothelial vascular lining, blood pressure, and the major animal lineages. The appearance of a complete or incomplete endothelial vascular lining is shown, along with an indication of general blood pressures for each group. Downward arrow indicates low blood pressure; upward arrow indicates high blood pressure. Adapted, with permission, from (83).


Figure 5. Mechanisms of cardiac regulation. (A). Intrinsic cardiac regulation: The neurogenic decapod heart contracts in response to pacemaker cells associated with the cardiac ganglion located in or on the dorsal aspect of the heart. These interneurons synapse with larger motoneurons that innervate cardiac muscle fibers directly and through extensive dendritic ramifications control both rate and strength of cardiac contractions. Extrinsic cardiac regulation: The cardiac ganglion, myocardia, ostia, suspensory ligaments, and arterial valve are all under extrinsic neuronal and neurohormonal control. The rate and force of cardiac contraction are modulated through cardioregulatory nervous input to both the cardiac ganglion and myocardia. Through the thoracic ganglion (dorsal nerve) two pair of cardio accelerator nerves (SN III) and one pair of cardio inhibitor nerves (SN II) influence the rate of depolarization of the pacemaker cells in the cardiac ganglion and force of myocardia contraction. Neurohormonal control of cardiac function is through the pericardial organ (PO), which releases an array of cardioactive substances into the paricardial sinus in response to dorsal nerve input via the neuroregulatory fibers. (B) Cardiac contraction is initiated by the cardiac ganglion, resulting in the generation of tension and myocardial contraction. The myocardia is composed of a three‐dimensional array of fibers arranged around the lumen of the heart (B3) and forces hemolymph into multiple arterial systems through the arterial valves (B2). Both nervous regulate arterial and ostial valve tone and neurohormonal input to facilitate coordinated and functional contraction (B1). B1 adapted, with permission, from (6), B2 and B3 adapted, with permission, from (369).


Figure 6. The functional linkage between the actions of the cardiac ganglion and the generation of hemolymph pressure to drive blood through the circulatory system is myocardial contraction. The decapod (Procambarus clarkii) cardiac cycle begins with systole, isovolumic contraction (muscle fiber depolarization with the generation of pressure or tension) as seen by the rapid rise in intracardiac pressure which rapidly igoes from close to zero to approximately 1.33 kPa. A notch similar to the dicrotic notch seen in mammalian ventricular pressure profiles is observed as the multiple arterial valves open due to the ventricular‐arterial pressure difference. Intracardiac and arterial pressures equalize once the arterial valves are open and hemolymph is propelled out of the ventricle into the arteries during the ejection phase. Arterial pressures are maintained above intracardiac pressure once the arterial valves close and the heart goes into isovolumic relaxation. Arterial hemolymph pressure diminishes slowly due to the passive elastic properties of the major vessels leaving the heart. Diastole or ventricular filling occurs as the result of a pericardial‐intracardiac pressure difference. During diastole, pericardial pressure continues to increase as hemolymph moves from the infrabranchial sinus through the gills and into the pericardial region. Open ostial valves allow the pressure difference to drive hemolymph into the ventrical during the filling phase, which ends with onset of the next systolic contrition (478).


Figure 7. A comparative scheme of the sources of activator Ca2+ during excitation‐contraction coupling in mammalian (A) and teleost (B) ventricular myocytes. Both cardiomyocytes are approximately the same length, but the teleost cell is narrower, elliptical in cross section, lacks transverse tubules, has a less well‐developed SR, and has a much higher surface area to volume ratio. Contractile activity in all vertebrate hearts depends, in large part, on how much Ca2+ is delivered, to myofilaments. In the mammalian cardiomyocyte, activator Ca2+ comes from extracellular Ca2+ entering the cell through Ca2+ channels (DHPR, #1 and 2) and Na+/Ca2+ exchangers (reverse mode, #3) on the sarcolemma and transverse tubules (T tubules). Ca2+ influx also triggers Ca2+ release from the SR (intracellular Ca2+ store) by the RyR (#4). Relaxation occurs by SR Ca2+ pumps (SERCA, #6), sarcolemmal Ca2+ pumps (#7), and Na+/Ca2+ exchangers (#8). The primary source of Ca2+ for contraction in the teleost cardiomyocyte is extracellular with transsarcolemmal influx through Ca2+ channels (#1) or Na+/Ca2+ exchangers (#2) in reverse mode. Depending on the fish species and environmental conditions, SR Ca2+ may also be important (#4). For relaxation, teleosts rely on sarcolemmal Ca2+ pumps (#5), Na+/Ca2+ exchangers (#6), and possibly SR Ca2+ pumps (#7). Based on information in references (40, 528, 593). See text for additional details.


Figure 8. A list of known regulators of ventricular function during a cardiac cycle in vertebrates. Although blood is shown as red, reflecting complete oxygenation, the vertebrate ventricle may pump different degrees of oxygenated or deoxygenated blood. See text for details.


Figure 9. Summary of diving specializations in a generic seal species.


Figure 10. Summary of features aiding to high‐altitude flight in bar‐headed goose either as avian general traits (blue boxes) or species‐specific specializations (orange boxes). Reprinted from (509) with permission.


Figure 11. Summary of specializations to account for gravitational effects in the cardiovascular system of the giraffe.
References
 1.Agnisola C, Masullo P, Mustafa T. Short‐term responses of coronary circulation to cortisol and estrogen in trout (Oncorhynchus mykiss). Gen Comp Endocrinol 135: 210‐216, 2004.
 2.Aho E, Vornanen M. Contractile properties of atrial and ventricular myocardium of the heart of rainbow trout Oncorhynchus mykiss: Effects of thermal acclimation. J Exp Biol 202(Pt 19): 2663‐2677, 1999.
 3.Aho E, Vornanen M. Effects of adenosine on the contractility of normoxic rainbow trout heart. J Comp Physiol [B] 172: 217‐225, 2002.
 4.Airriess C, McMahon B. Cardiovascular adaptations enhance tolerance of environmental hypoxia in the crab cancer magister. J Exp Biol 190: 23‐41, 1994.
 5.Aktan F. iNOS‐mediated nitric oxide production and its regulation. Life Sci 75: 639‐653, 2004.
 6.Alexandrowicz J. Memoirs: the innervation of the heart of the Crustacea. I. Decapoda. Q J Microsc Sci 2: 181‐249, 1932.
 7.Allen D, Kentish J. The cellular basis of the length‐tension relation in cardiac muscle. J Mol Cell Cardiol 17: 821‐840, 1985.
 8.Almers W, McCleskey EW. Non‐selective conductance in calcium channels of frog muscle: calcium selectivity in a single‐file pore. J Physiol 353: 585‐608, 1984.
 9.Alpert NR, Hamrell BB, Mulieri LA. Heart muscle mechanics. Annu Rev Physiol 41: 521‐537, 1979.
 10.Altimiras J, Franklin CE, Axelsson M. Relationships between blood pressure and heart rate in the saltwater crocodile Crocodylus porosus. J Exp Biol 201: 2235‐2242, 1998.
 11.Altimiras J, Hove‐Madsen L, Gesser H. Ca2+ uptake in the sarcoplasmic reticulum from the systemic heart of octopod cephalopods. J Exp Biol 202: 2531‐2537, 1999.
 12.Anderson BR, Granzier HL. Titin‐based tension in the cardiac sarcomere: molecular origin and physiological adaptations. Prog Biophys Mol Biol 110: 204‐217, 2012.
 13.Ando K. An immunohistochemical study on the innervation of two peptidergic (NPY and VIP) nerves in the cerebral arterial tree and choroid plexus of the newt (Amphibia: Urodela). J Vet Med Sci 58: 337‐342, 1996.
 14.Ando K, Kusaba H, Soh T, Iwamoto H. Different patterns of vasoactive intestinal polypeptide (VIP)‐immunoreactive and acetylcholinesterase (AChE)‐positive innervation in the internal carotid artery and cerebral arterial tree of the quail. J Vet Med Sci 69: 177‐183, 2007.
 15.Andreakis N, D'Aniello S, Albalat R, Patti FP, Garcia‐Fernandez J, Procaccini G, Sordino P, Palumbo A. Evolution of the nitric oxide synthase family in metazoans. Mol Biol Evol 28: 163‐179, 2011.
 16.Andreasen P. Free and total calcium concentrations in the blood of rainbow trout, Salmo gairdneri, during ‘stress’ conditions. J Exp Biol 118: 111‐120, 1985.
 17.Armstrong CM, Bezanilla FM, Horowicz P. Twitches in the presence of ethylene glycol bis(β‐aminoethyl ether)‐N,N′‐tetraacetic acid. BBA-Bioenergetics 267: 605‐608, 1972.
 18.Armstrong RB, Essen‐Gustavsson B, Hoppeler H, Jones JH, Kayar SR, Laughlin MH, Lindholm A, Longworth KE, Taylor CR, Weibel ER. O2 delivery at VO2 max and oxidative capacity in muscles of standardbred horses. J Appl Physiol 73: 2274‐2282, 1992.
 19.Ask JA. Comparative aspects of adrenergic receptors in the hearts of lower vertebrates. Comp Biochem Physiol A 76: 543‐552, 1983.
 20.Axelsson M, Davison W, Forster ME, Farrell AP. Cardiovascular responses of the red‐blooded antarctic fishes Pagothenia bernacchii and P. borchgrevinki. J Exp Biol 167: 179‐201, 1992.
 21.Axelsson M, Driedzic WR, Farrell AP, Nilsson S. Regulation of cardiac output and gut blood flow in the sea raven, Hemitripterus americanus. Fish Physiol Biochem 6: 315‐326, 1989.
 22.Axelsson M, Farrell AP. Coronary blood flow in vivo in the coho salmon (Oncorhynchus kisutch). Am J Physiol 264: R963‐R971, 1993.
 23.Axelsson M, Farrell AP, Nilsson S. Effects of hypoxia and drugs on the cardiovascular dynamics of the Atlantic hagfish Myxine glutinosa. J Exp Biol 151: 297‐316, 1990.
 24.Axelsson M, Fritsche R. Effects of exercise, hypoxia and feeding on the gastrointestinal blood flow in the Atlantic cod Gadus morhua. J Exp Biol 158: 181‐198, 1991.
 25.Backx PH, Gao WD, Azan‐Backx MD, Marban E. The relationship between contractile force and intracellular [Ca2+] in intact rat cardiac trabeculae. J Gen Physiol 105: 1‐19, 1995.
 26.Badeer HS. Does gravitational pressure of blood hinder flow to the brain of the giraffe? Comp Biochem Physiol A 83: 207‐211, 1986.
 27.Badeer HS, Hicks JW. Hemodynamics of vascular ‘waterfall’: Is the analogy justified? Respir Physiol 87: 205‐217, 1992.
 28.Bailey JR, West JL, Driedzic WR. Heart growth associated with sexual maturity in male rainbow trout (Oncorhynchus mykiss) is hyperplastic. Comp Biochem Physiol Biochem Mol Biol 118: 607‐611, 1997.
 29.Balashov NV, Fange R, Govyrin VA, Leont'eva GR, Nilsson S, Prozorovskaya MP. On the adrenergic system of ganoid fish: The beluga, Huso huso (chondrostei). Acta Physiol Scand 111: 435‐440, 1981.
 30.Balligand JL, Feron O, Dessy C. eNOS activation by physical forces: From short‐term regulation of contraction to chronic remodeling of cardiovascular tissues. Physiol Rev 89: 481‐534, 2009.
 31.Balment RJ, Masini MA, Vallarino M, Conlon JM. Cardiovascular actions of lungfish bradykinin in the unanaesthetised African lungfish, Protopterus annectens. Comp Biochem Physiol A 131: 467‐474, 2002.
 32.Beall CM, Laskowski D, Strohl KP, Soria R, Villena M, Vargas E, Alarcon AM, Gonzales C, Erzurum SC. Pulmonary nitric oxide in mountain dwellers. Nature 414: 411‐412, 2001.
 33.Belardinelli L. Adenosine system in the heart. Drug Dev Res 28: 263‐267, 1993.
 34.Belaud A, Peyraud C. Etude preliminaire du debit coronaire sur coeur perfuse de poisson. J Physiol 63: 165A, 1971.
 35.Belman BW, Childress JJ. Circulatory adaptations to the oxygen minimum layer in the bathypelagic mysid Gnathophausia ingens. Biol Bull 150: 15‐37, 1976.
 36.Bennett AF. Activity metabolism of the lower vertebrates. Annu Rev Physiol 40: 447‐469, 1978.
 37.Bennett AF, Ruben JA. Endothermy and activity in vertebrates. Science 206: 649‐654, 1979.
 38.Bennett MB. Efferent branchial artery reactivity in the Blacktip reef shark, Carckarhinus melanopterus (Carcharhinidae: Elasmobranchii). Comp Biochem Physiol C Pharmacol Toxicol Endocrinol 114: 165‐170, 1996.
 39.Berne RM, Rubio R. Regulation of coronary blood flow. Adv Cardiol 12: 303‐317, 1974.
 40.Bers D. Excitation‐Contraction Coupling and Cardiac Contractile Force. Netherlands: Springer Science & Business Media, 2001.
 41.Bers DM. Cardiac excitation‐contraction coupling. Nature 415: 198‐205, 2002.
 42.Bers DM. Regulation of cellular calcium in cardiac myocytes. Comprehensive Physiology. John Wiley & Sons, 2011.
 43.Bers DM, Bridge JH. Relaxation of rabbit ventricular muscle by Na‐Ca exchange and sarcoplasmic reticulum calcium pump. Ryanodine and voltage sensitivity. Circ Res 65: 334‐342, 1989.
 44.Bers DM, Stiffel VM. Ratio of ryanodine to dihydropyridine receptors in cardiac and skeletal muscle and implications for E‐C coupling. Am J Physiol 264: C1587‐C1593, 1993.
 45.Bevegård S, Holmgren A, Jonsson B. The effect of body position on the circulation at rest and during exercise, with special reference to the influence on the stroke volume. Acta Physiol Scand 49: 279‐298, 1960.
 46.Bickler PE. Effects of temperature and anoxia on regional cerebral blood flow in turtles. Am J Physiol 262: R538‐R541, 1992.
 47.Birks EK, Mathieu‐Costello O, Fu Z, Tyler WS, West JB. Very high pressures are required to cause stress failure of pulmonary capillaries in thoroughbred racehorses. J Appl Physiol (1985) 82: 1584‐1592, 1997.
 48.Bishop CM. Heart mass and the maximum cardiac output of birds and mammals: implications for estimating the maximum aerobic power input of flying animals. Philos Trans R Soc Lond B Biol Sci 352: 447‐456, 1997.
 49.Bishopric NH. Evolution of the heart from bacteria to man. Ann N Y Acad Sci 1047: 13‐29, 2005.
 50.Black CP, Tenney SM. Oxygen transport during progressive hypoxia in high‐altitude and sea‐level waterfowl. Respir Physiol 39: 217‐239, 1980.
 51.Blank JM, Farwell CJ, Morrissette JM, Schallert RJ, Block BA. Influence of swimming speed on metabolic rates of juvenile Pacific bluefin tuna and yellowfin tuna. Physiol Biochem Zool 80: 167‐177, 2007.
 52.Blatchford JG. Haemodynamics of Carcinus maenas (L.). Comp Biochem Physiol A Physiol 39: 193‐202, 1971.
 53.Borgheresi RA, Leroy JM, Yogi A, DosSantos RA, Breno MC, Tostes RC. Pharmacologic and molecular characterization of the vascular ETA receptor in the venomous snake Bothrops jararaca. Exp Biol Med 231: 729‐735, 2006.
 54.Bossen EH, Sommer JR. Comparative stereology of the lizard and frog myocardium. Tissue Cell 16: 173‐178, 1984.
 55.Bossen EH, Sommer JR, Waugh RA. Comparative stereology of the mouse and finch left ventricle. Tissue Cell 10: 773‐784, 1978.
 56.Bourne G, McMahon B. Control of cardiac‐output and its distribution in crustacean open circulatory systems. J Physiol (Lond) P134, 1989.
 57.Boutilier R, Emilio M, Shelton G. The effects of mechanical work on electrolyte and water distribution in amphibian skeletal muscle. J Exp Biol 120: 333‐350, 1986.
 58.Boutilier RG, McDonald DG, Toews DP. The effects of enforced activity on ventilation, circulation and blood acid‐base balance in the aquatic gill‐less urodele, Cryptobranchus alleganiensis; a comparison with the semi‐terrestrial anuran, Bufo marinus. J Exp Biol 84: 289‐302, 1980.
 59.Brady AJ. Physiology of the amphibian heart. Physiol Amphib 211‐250, 1964.
 60.Brady AJ. Mechanical properties of cardiac fibers. Handbook of Physiology, Vol. 1, 1979.
 61.Brauer EB. Osmoregulation in the fresh water sponge, Spongilla lacustris. J Exp Zool 192: 181‐192, 1975.
 62.Brauman J, Delvigne C, Deconinck I, Willems D. Factors affecting the determination of ionized calcium in blood. Scand J Clin Lab Invest 165: 27‐31, 1983.
 63.Brette F, Orchard C. T‐tubule function in mammalian cardiac myocytes. Circ Res 92: 1182‐1192, 2003.
 64.Brill RW, Bushnell PG. Metabolic and cardiac scope of high energy demand teleosts, the tunas. Can J Zool 69: 2002‐2009, 1991.
 65.Brodeur JC, Dixon DG, McKinly RS. Assessment of cardiac output as a predictor of metabolic rate in rainbow trout. J Fish Biol 58: 439‐452, 2001.
 66.Bron KM, Murdaugh HV, Jr., Millen JE, Lenthall R, Raskin P, Robin ED. Arterial constrictor response in a diving mammal. Science 152: 540‐543, 1966.
 67.Brøndum E, Hasenkam JM, Secher NH, Bertelsen MF, Grøndahl C, Petersen KK, Buhl R, Aalkjaer C, Baandrup U, Nygaard H. Jugular venous pooling during lowering of the head affects blood pressure of the anesthetized giraffe. Am J Physiol Regul Integr Comp Physiol 297: R1058‐R1065, 2009.
 68.Broughton BR, Donald JA. Dual mechanisms for nitric oxide control of large arteries in the estuarine crocodile Crocodylus porosus. J Exp Biol 210: 129‐137, 2007.
 69.Broughton BRS, Donald JA. Nitric oxide regulation of the central aortae of the toad Bufo marinus occurs independently of the endothelium. J Exp Biol 205: 3093‐3100, 2002.
 70.Brum G, Osterrieder W, Trautwein W. Beta‐adrenergic increase in the calcium conductance of cardiac myocytes studied with the patch clamp. Pflugers Arch 401: 111‐118, 1984.
 71.Brusca RC, Brusca GJ. Invertebrates. Sunderland, Massachusetts: Sinauer Associates, 2003.
 72.Brutsaert DL, Sonnenblick EH. Cardiac muscle mechanics in the evaluation of myocardial contractility and pump function: Problems, concepts, and directions. Prog Cardiovasc Dis 16: 337‐361, 1973.
 73.Bullard R. Vertebrates at altitudes. In: Yousef M, Horvath S, Bullard R, editors. Physiological Adaptations: Desert and Mountain. New York: Academic Press, 1972, p. 209.
 74.Burggren W, Bemis W. Studying Physiological Evolution: Paradigms and Pitfalls. Nitecki MH, editor. Oxford: Oxford University Press, 1990, p. 191‐228.
 75.Burggren W, Farrell A, Lillywhite H. Vertebrate cardiovascular systems. Handbook of Comparative Physiology. New York: Oxford university press, 1997, pp. 215‐308.
 76.Burggren W, Johansen K. Ventricular haemodynamics in the monitor lizard Varanus Exanthematicus: Pulmonary and systemic pressure separation. J Exp Biol 96: 343‐354, 1982.
 77.Burggren W, Khorrami S, Pinder A, Sun T. Body, eye, and chorioallantoic vessel growth are not dependent on cardiac output level in day 3–4 chicken embryos. Am J Physiol Regul Integr Comp Physiol 287(6): R1399‐R1406, 2004.
 78.Burggren WW. A quantitative analysis of ventilation tachycardia and its control in two chelonians, Pseudemys scripta and Testudo graeca. J Exp Biol 63: 367‐380, 1975.
 79.Burggren WW. Cardiac design in lower vertebrates: What can phylogeny reveal about ontogeny? Experientia 44: 919‐930, 1988.
 80.Burggren WW. Cardiovascular development and angiogenesis in the early vertebrate embryo. Cardiovascular Engineering and Technology 4: 234‐245, 2013.
 81.Burggren WW, Farrell AP, Lillywhite HB. Vertebrate Cardiovascular Systems. Oxford: Oxford University Press, 1997, pp. 215‐308.
 82.Burggren WW, McMahon BR. Circulation. In: Burggren WW, McMahon BR, editors. Biology of Land Crabs. New York: Cambridge University Press, 1988, pp. 298‐332.
 83.Burggren WW, Reiber C. Evolution of cardiovascular systems and their endothelial linings. Endothelial Biomedicine 29‐49, 2007.
 84.Burggren WW, Warburton SJ, Slivkoff MD. Interruption of cardiac output does not affect short‐term growth and metabolic rate in day 3 and 4 chick embryos. J Exp Biol 203: 3831‐3838, 2000.
 85.Burton AC. Physiology and Biophysics of the Circulation: An Introductory Text. Chicago: Year Book Medical Publishers, 1972.
 86.Bushnell P, Jones D. Cardiovascular and respiratory physiology of tuna: Adaptations for support of exceptionally high metabolic rates. Environ Biol Fish 40: 303‐318, 1994.
 87.Butler P. Respiration during flight and diving in birds. In: Addink ADF, Spronk N, editors. Exogenous and Endogenous Influences in Metabolic and Neural Control. New York, Oxford: Pergamon Press, 1982, pp. 103‐114.
 88.Butler PJ. Exercise in Birds. J Exp Biol 160: 233‐262, 1991.
 89.Butler PJ. High fliers: the physiology of bar‐headed geese. Comp Biochem Physiol Biochem Mol Biol 156: 325‐329, 2010.
 90.Butler PJ, Axelsson M, Ehrenstrom F, Metcalfe JD, Nilsson S. Circulating catecholamines and swimming performance in the Atlantic Cod, Gadus Morhua. J Exp Biol 141: 377‐387, 1989.
 91.Butler PJ, Milsom WK, Woakes AJ. Respiratory, cardiovascular and metabolic adjustments during steady state swimming in the green turtle, Chelonia mydas. J Comp Physiol [B] 154: 167‐174, 1984.
 92.Butler PJ, West NH, Jones DR. Respiratory and cardiovascular responses of the pigeon to sustained, level flight in a wind‐tunnel. J Exp Biol 71: 7‐26, 1977.
 93.Butler PJ, Woakes AJ. Changes in heart rate and respiratory frequency during natural behaviour of ducks, with particular reference to diving. J Exp Biol 79: 283‐300, 1979.
 94.Cabanac A, Folkow LP, Blix AS. Volume capacity and contraction control of the seal spleen. J Appl Physiol 82: 1989‐1994, 1997.
 95.Cachelin AB, de Peyer JE, Kokubun S, Reuter H. Ca2+ channel modulation by 8‐bromocyclic AMP in cultured heart cells. Nature 304: 462‐464, 1983.
 96.Carneiro JJ, Donald DE. Blood reservoir function of dog spleen, liver, and intestine. Am J Physiol Regul Integr Comp Physiol 232: H67‐H72, 1977.
 97.Carroll JD, Hess OM, Hirzel HO, Krayenbuehl HP. Dynamics of left ventricular filling at rest and during exercise. Circulation 68: 59‐67, 1983.
 98.Casson DM, Ronald K. The harp seal, Pagophilus groenlandicus (Erxleben, 1777). XIV. Cardiac arrythmias. Comp Biochem Physiol A Physiol 50: 307‐314, 1975.
 99.Castellini JM, Castellini MA. Estimation of splenic volume and its relationship to long‐duration apnea in seals. Physiol Zool 619‐627, 1993.
 100.Cavey MJ, Chan KS, Wilkens JL. Microscopic anatomy of the thin‐walled vessels leaving the heart of the lobster Homarus americanus: Anterior median artery. Invertebr Biol 127: 189‐200, 2008.
 101.Cerretelli P, Piiper J, Mangili F, Cuttica F, Ricci B. Circulation in exercising dogs. J Appl Physiol 19: 29‐32, 1964.
 102.Chapman RA, Rodrigo GC. The dependence of the relaxation of tension of frog atrial‐trabeculae on the sodium‐calcium exchange: A voltage‐clamp study. Q J Exp Physiol 70: 447‐459, 1985.
 103.Chase RE, de Garis CF. Arteriae coronariae (cordis) in the higher primates. Am J Phys Anthropol 24: 427‐448, 1939.
 104.Chemla D, Lecarpentier Y, Martin J, Clergue M, Antonetti A, Hatt P. Relationship between inotropy and relaxation in rat myocardium. Am J Physiol Heart Circ Physiol 250: H1008‐H1016, 1986.
 105.Childress JJ. The respiratory rates of mid‐water crustaceans as a function of depth of occurrence and relative to the oxygen minimum layer off southern California. Comp Biochem Physiol A Mol Integr Physiol 50: 787‐799, 1975.
 106.Churcott CS, Moyes CD, Bressler BH, Baldwin KM, Tibbits GF. Temperature and pH effects on Ca2 +sensitivity of cardiac myofibrils: A comparison of trout with mammals. Am J Physiol Regul Integr Comp Physiol 267: R62‐R70, 1994.
 107.Clark JJ, Clark RJ, McMinn JT, Rodnick KJ. Microvascular and biochemical compensation during ventricular hypertrophy in male rainbow trout. Comp Biochem Physiol Biochem Mol Biol 139: 695‐703, 2004.
 108.Clark RB, Cowey JB. Factors controlling the change of shape of certain Nemertean and Turbellarian worms. J Exp Biol 35: 731‐748, 1958.
 109.Clark RJ, Rodnick KJ. Morphometric and biochemical characteristics of ventricular hypertrophy in male rainbow trout (Oncorhynchus mykiss). J Exp Biol 201: 1541‐1552, 1998.
 110.Clark TD, Sandblom E, Cox GK, Hinch SG, Farrell AP. Circulatory limits to oxygen supply during an acute temperature increase in the Chinook salmon (Oncorhynchus tshawytscha). Am J Physiol Regul Integr Comp Physiol 295: R1631‐R1639, 2008.
 111.Conlon JM, Hicks JW, Smith DD. Isolation and biological activity of a novel kinin ([Thr6] bradykinin) from the turtle, Pseudemys scripta. Endocrinology 126: 985‐991, 1990.
 112.Conlon JM, Platzack B, Marra LE, Youson JH, Olson KR. Isolation and biological activity of [Trp5]bradykinin from the plasma of the phylogenetically ancient fish, the bowfin and the longnosed gar. Peptides 16: 485‐489, 1995.
 113.Conlon JM, Yano K. Kallikrein generates angiotensin II but not bradykinin in the plasma of the urodele, Amphiuma tridactylum. Comp Biochem Physiol C Pharmacol Toxicol Endocrinol 110: 305‐311, 1995.
 114.Contestabile A. Histochemical characterization of cholinesterase activity in the frog brain with special reference to its localization on the wall of blood vessels. Histochem J 8: 513‐521, 1976.
 115.Convertino VA, Morey ER, Greenleaf JE. Reduction in plasma calcium during exercise in man. Nature 299: 658, 1982.
 116.Cooke IM. Studies on the crustacean cardiac ganglion. Comp Biochem Physiol C Pharmacol Toxicol Endocrinol 91: 205‐218, 1988.
 117.Cotter PA, Han AJ, Everson JJ, Rodnick KJ. Cardiac hemodynamics of the rainbow trout (Oncorhynchus mykiss) using simultaneous Doppler echocardiography and electrocardiography. J Exp Zool A Ecol Genet Physiol 309: 243‐254, 2008.
 118.Covell JW, Ross J. Systolic and diastolic function (mechanics) of the intact heart. Handbook of Physiology. 2011, pp. 741‐785.
 119.Cremona G, Higenbottam T, Takao M, Bower EA, Hall LW. Nature and site of action of endogenous nitric oxide in vasculature of isolated pig lungs. J Appl Physiol 82: 23‐31, 1997.
 120.Crisp E. Contributions to the anatomy of the giraffe, with an account of the length of the alimentary canal of many of the ruminants, as measured by the author. P Zool Soc Lond 63‐68, 1864.
 121.Crossley II DA, Altimiras J, Wang T. Hypoxia elicits an increase in pulmonary vasculature resistance in anaesthetised turtles (Trachemys scripta). J Exp Biol 201: 3367‐3375, 1998.
 122.Crossley II DA, Burggren WW. Development of cardiac form and function in ectothermic sauropsids. J Morphol 270: 1400‐1412, 2009.
 123.Crossley II DA, Wang T, Altimiras J. Role of nitric oxide in the systemic and pulmonary circulation of anesthetized turtles (Trachemys scripta). J Exp Zool 286: 683‐689, 2000.
 124.Dalton N, Shabetai R, Bhargava V, Lai NC, Graham JB. Echocardiographic and hemodynamic determinations of the ventricular filling pattern in some teleost fishes. Physiol Biochem Zool 71: 157‐167, 1998.
 125.Damkjær M, Bertelsen M, Grondahl C, Hasenkam M, Wang T, Brondum E, Candy G, Bie P. Low blood volume in the giraffe (Giraffa camelopardalis). FASEB J 25: 1027.1017, 2011.
 126.Dasiewicz PJ, Conlon JM, Anderson WG. Cardiovascular and vasoconstrictive actions of skate bradykinin in the little skate, Leucoraja erinacea (Elasmobranchii). Gen Comp Endocrinol 174: 89‐96, 2011.
 127.Davidson B, Levine M. Evolutionary origins of the vertebrate heart: Specification of the cardiac lineage in Ciona intestinalis. Proc Natl Acad Sci U S A 100: 11469‐11473, 2003.
 128.Davidson GW, Wilkens JL, Lovell P. Neural control of the lateral abdominal arterial valves in the Lobster Homarus americanus. Biol Bull 194: 72‐82, 1998.
 129.Davie PS, Daxboeck C. Anatomy and adrenergic pharmacology of the coronary vascular bed of Pacific blue marlin (Makaira nigricans). Can J Zool 62: 1886‐1888, 1984.
 130.Davie PS, Farrell AP. The coronary and luminal circulations of the myocardium of fishes. Can J Zool 69: 1993‐2001, 1991.
 131.Davie PS, Farrell AP, Franklin CE. Cardiac performance of an isolated eel heart: Effects of hypoxia and responses to coronary artery perfusion. J Exp Zool 262: 113‐121, 1992.
 132.Davie PS, Forster ME, Davison B, Satchell GH. Cardiac function in the New Zealand hagfish, Eptatretus cirrhatus. Physiol Zool 60: 233‐240, 1987.
 133.Davie PS, Thorarensen H. Heart growth in rainbow trout in response to exogenous testosterone and 17‐α methyltestosterone. Comp Biochem Physiol A Physiol 117: 227‐230, 1997.
 134.Davies DG. Chemical regulation of cerebral blood flow in turtles. Am J Physiol Regul Integr Comp Physiol 260: R382‐R384, 1991.
 135.Davis RW, Castellini MA, Kooyman GL, Maue R. Renal glomerular filtration rate and hepatic blood flow during voluntary diving in Weddell seals. Am J Physiol Regul Integr Comp Physiol 245: R743‐R748, 1983.
 136.Davison W, Axelsson M, Nilsson S, Forster ME. Cardiovascular control in Antarctic notothenioid fishes. Comp Biochem Physiol A Physiol 118: 1001‐1008, 1997.
 137.Dawson EA, Secher NH, Dalsgaard MK, Ogoh S, Yoshiga CC, González‐Alonso J, Steensberg A, Raven PB. Standing up to the challenge of standing: A siphon does not support cerebral blood flow in humans. Am J Physiol Regul Integr Comp Physiol 287: R911‐R914, 2004.
 138.Day SB, Johnson JA. The distribution of the coronary arteries of the rabbit. Anat Rec 132: 633‐643, 1958.
 139.de Ceccatty MP. Coordination in sponges. The foundations of integration. Amer Zool 14: 895‐903, 1974.
 140.di Prampero PE. Metabolic and circulatory limitations to VO2 max at the whole animal level. J Exp Biol 115: 319‐331, 1985.
 141.Domaingue C. Anaesthesia for neurosurgery in the sitting position: A practical approach. Anaesth Intensive Care 33: 323, 2005.
 142.Dombkowski RA, Russell MJ, Olson KR. Hydrogen sulfide as an endogenous regulator of vascular smooth muscle tone in trout. Am J Physiol Regul Integr Comp Physiol 286: R678‐R685, 2004.
 143.Dombkowski RA, Russell MJ, Schulman AA, Doellman MM, Olson KR. Vertebrate phylogeny of hydrogen sulfide vasoactivity. Am J Physiol Regul Integr Comp Physiol 288: R243‐R252, 2005.
 144.Donald JA, Broughton BR. Nitric oxide control of lower vertebrate blood vessels by vasomotor nerves. Comp Biochem Physiol A Mol Integr Physiol 142: 188‐197, 2005.
 145.Donald JA, Broughton BR, Bennett MB. Vasodilator mechanisms in the dorsal aorta of the giant shovelnose ray, Rhinobatus typus (Rajiformes; Rhinobatidae). Comp Biochem Physiol A Mol Integr Physiol 137: 21‐31, 2004.
 146.Driedzic WR, Bailey JR, Sephton DH. Cardiac adaptations to low temperature in non‐polar teleost fish. J Exp Zool 275: 186‐195, 1996.
 147.Driedzic WR, Gesser H. Differences in force‐frequency relationships and calcium dependency between elasmobranch and teleost hearts. J Exp Biol 140: 227‐241, 1988.
 148.Driedzic WR, Gesser H. Energy metabolism and contractility in ectothermic vertebrate hearts: Hypoxia, acidosis, and low temperature. Physiol Rev 74: 221‐258, 1994.
 149.Durmowicz AG, Hofmeister S, Kadyraliev TK, Aldashev AA, Stenmark KR. Functional and structural adaptation of the yak pulmonary circulation to residence at high altitude. J Appl Physiol 74: 2276‐2285, 1993.
 150.Eddy FB, Tibbs P. Effects of nitric oxide synthase inhibitors and a substrate, L‐arginine, on the cardiac function of juvenile salmonid fish. Comp Biochem Physiol C Pharmacol Toxicol Endocrinol 135: 137‐144, 2003.
 151.Egginton S, Cordiner S. Cold‐induced angiogenesis in seasonally acclimatized rainbow trout (Oncorhynchus mykiss). J Exp Biol 200: 2263‐2268, 1997.
 152.Elkins N. High‐altitude flight by swans. Brit Birds 72: 238‐239, 1979.
 153.Elliott NM, Andrews RD, Jones DR. Pharmacological blockade of the dive response: Effects on heart rate and diving behaviour in the harbour seal (Phoca vitulina). J Exp Biol 205: 3757‐3765, 2002.
 154.Elsner R. Splenic oxygen storage and blood viscosity in seals. Mar Mammal Sci 11: 93‐96, 1995.
 155.Elsner R, Hanafee WN, Hammond DD. Angiography of the inferior vena cava of the harbor seal during simulated diving. Am J Physiol 220: 1155‐1157, 1971.
 156.Elsner R, Kenney D. Muscle blood flow and heart rate in exercising horse. Fed Proc 25(2): P 1, 333. 1966.
 157.Elsner R, Scholander P, Craig A, Dimond E, Irving L, Pilson M, Johansen K, Bradstreet E. A venous blood oxygen reservoir in the diving elephant seal. Physiologist 7: 1, 1964.
 158.Endoh M, Blinks JR. Actions of sympathomimetic amines on the Ca2+ transients and contractions of rabbit myocardium: Reciprocal changes in myofibrillar responsiveness to Ca2+ mediated through alpha‐ and beta‐adrenoceptors. Circ Res 62: 247‐265, 1988.
 159.Erbel R, Schweizer P, Krebs W, Langen H‐J, Meyer J, Effert S. Effects of heart rate changes on left ventricular volume and ejection fraction: A 2‐dimensional echocardiographic study. Am J Cardiol 53: 590‐597, 1984.
 160.Eriksen M, Waaler BA, Walloe L, Wesche J. Dynamics and dimensions of cardiac output changes in humans at the onset and at the end of moderate rhythmic exercise. J Physiol 426: 423‐437, 1990.
 161.Erzurum SC, Ghosh S, Janocha AJ, Xu W, Bauer S, Bryan NS, Tejero J, Hemann C, Hille R, Stuehr DJ, Feelisch M, Beall CM. Higher blood flow and circulating NO products offset high‐altitude hypoxia among Tibetans. Proc Natl Acad Sci U S A 104: 17593‐17598, 2007.
 162.Evans DH, Gunderson MP. A prostaglandin, not NO, mediates endothelium‐dependent dilation in ventral aorta of shark (Squalus acanthias). Am J Physiol Regul Integr Comp Physiol 274: R1050‐R1057, 1998.
 163.Evans DH, Harrie AC. Vasoactivity of the ventral aorta of the American eel (Anguilla rostrata), Atlantic hagfish (Myxine glutinosa), and sea lamprey (Petromyzon marinus). J Exp Zool 289: 273‐284, 2001.
 164.Fabiato A. Calcium‐induced release of calcium from the cardiac sarcoplasmic reticulum. Am J Physiol 245: C1‐C14, 1983.
 165.Faraci FM. Adaptations to hypoxia in birds: How to fly high. Ann Rev Physiol 53: 59‐70, 1991.
 166.Faraci FM, Fedde MR. Regional circulatory responses to hypocapnia and hypercapnia in bar‐headed geese. Am J Physiol Regul Integr Comp Physiol 250: R499‐R504, 1986.
 167.Faraci FM, Kilgore DL, Jr., Fedde MR. Attenuated pulmonary pressor response to hypoxia in bar‐headed geese. Am J Physiol Regul Integr Comp Physiol 247: R402‐R403, 1984.
 168.Faraci FM, Kilgore DL, Jr., Fedde MR. Oxygen delivery to the heart and brain during hypoxia: Pekin duck vs. bar‐headed goose. Am J Physiol Regul Integr Comp Physiol 247: R69‐R75, 1984.
 169.Farias M, 3rd, Gorman MW, Savage MV, Feigl EO. Plasma ATP during exercise: Possible role in regulation of coronary blood flow. Am J Physiol Heart Circ Physiol 288: H1586‐H1590, 2005.
 170.Farmer CG. Evolution of the vertebrate cardio‐pulmonary system. Ann Rev Physiol 61: 573‐592, 1999.
 171.Farmer CG, Hicks JW. Circulatory impairment induced by exercise in the lizard Iguana iguana. J Exp Biol 203: 2691‐2697, 2000.
 172.Farrell A. Features heightening cardiovascular performance in fishes, with special reference to tunas. Comp Biochem Physiol A Physiol 113: 61‐67, 1996.
 173.Farrell A, Davie P, Franklin C, Johansen J, Brill R. Cardiac physiology in tunas. I. In vitro perfused heart preparations from yellowfin and skipjack tunas. Can J Zool 70: 1200‐1210, 1992.
 174.Farrell A, Hammons A, Graham M, Tibbits G. Cardiac growth in rainbow trout, Salmo gairdneri. Can J Zool 66: 2368‐2373, 1988.
 175.Farrell A, Johansen J, Suarez R. Effects of exercise‐training on cardiac performance and muscle enzymes in rainbow trout, Oncorhynchus mykiss. Fish Physiol Biochem 9: 303‐312, 1991.
 176.Farrell A, Wood S, Hart T, Driedzic W. Myocardial oxygen consumption in the sea raven, Hemitripterus americanus: The effects of volume loading, pressure loading and progressive hypoxia. J Exp Biol 117: 237‐250, 1985.
 177.Farrell AP. Coronary flow in a perfused rainbow trout heart. J Exp Biol 129: 107‐123, 1987.
 178.Farrell AP. Cardiac scope in lower vertebrates. Can J Zool 69: 1981‐1984, 1991.
 179.Farrell AP, Graham MS. Effects of adrenergic drugs on the coronary circulation of Atlantic salmon (Salmo salar). Can J Zool 64: 481‐484, 1986.
 180.Farrell AP, Jones DR. The heart. Cardiovasc Sys 12: 1‐88, 1992.
 181.Farrell AP, MacLeod K, Driedzic WR. The effects of preload, after load, and epinephrine on cardiac performance in the sea raven, Hemitripterus americanus. Can J Zool 60: 3165‐3171, 1982.
 182.Farrell AP, Steffensen JF. An analysis of the energetic cost of the branchial and cardiac pumps during sustained swimming in trout. Fish Physiol Biochem 4: 73‐79, 1987.
 183.Farrell AP, Steffensen JF. Coronary ligation reduces maximum sustained swimming speed in Chinook salmon, Oncorhynchus tshawytscha. Comp Biochem Physiol A Physiol 87: 35‐37, 1987.
 184.Fedak M, Pullen M, Kanwisher J. Circulatory responses of seals to periodic breathing: Heart rate and breathing during exercise and diving in the laboratory and open sea. Can J Zool 66: 53‐60, 1988.
 185.Feng J, Yano K, Monahan‐Earley R, Morgan ES, Dvorak AM, Sellke FW, Aird WC. Vascular bed‐specific endothelium‐dependent vasomomotor relaxation in the hagfish, Myxine glutinosa. Am J Physiol Regul Integr Comp Physiol 293: R894‐R900, 2007.
 186.Fick A. Ueber diffusion. Ann Phys-Berlin 170: 59‐86, 1855.
 187.Fick AV. On liquid diffusion. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science 10: 30‐39, 1855.
 188.Fischmeister R, Shrier A. Interactive effects of isoprenaline, forskolin and acetylcholine on Ca2+ current in frog ventricular myocytes. J Physiol 417: 213‐239, 1989.
 189.Fogh‐Andersen N, Christiansen TF, Komarmy L, Siggaard‐Andersen O. Measurement of free calcium ion in capillary blood and serum. Clin Chem 24: 1545‐1552, 1978.
 190.Forbes MS, Sperelakis N. Ultrastructure of mammalian cardiac muscle. Physiology and Pathophysiology of the Heart. US: Springer, 1984, pp. 3‐42.
 191.Forster M, Farrell A. The volumes of the chambers of the trout heart. Comp Biochem Physiol A Physiol 109: 127‐132, 1994.
 192.Forster ME. Performance of the heart of the hagfish, Eptatretus cirrhatus. Fish Physiol Biochem 6: 327‐331, 1989.
 193.Förstermann U, Closs EI, Pollock JS, Nakane M, Schwarz P, Gath I, Kleinert H. Nitric oxide synthase isozymes. Characterization, purification, molecular cloning, and functions. Hypertension 23: 1121‐1131, 1994.
 194.Foster JM, Forster ME, Olson KR. Different sensitivities of arteries and veins to vasoactive drugs in a hagfish, Eptatretus cirrhatus. Comp Biochem Physiol C Pharmacol Toxicol Endocrinol 148: 107‐111, 2008.
 195.Foxon GE. A description of the coronary arteries in dipnoan fishes and some remarks on their importance from the evolutionary standpoint. J Anat 84: 121‐131, 1950.
 196.Foxon GEH. Physiology of the amphibia. In: Moore JA, editor. Blood and Respiration, New York: Academic Press, 1964, pp. 151‐209.
 197.Franklin CE, Davie PS. Sexual maturity can double heart mass and cardiac power output in male rainbow trout. J Exp Biol 171: 139‐148, 1992.
 198.Franzini‐Armstrong C, Protasi F. Ryanodine receptors of striated muscles: A complex channel capable of multiple interactions. Physiol Rev 77: 699‐729, 1997.
 199.Frederich M, DeWachter B, Sartoris FJ, Portner HO. Cold tolerance and the regulation of cardiac performance and hemolymph distribution in Maja squinado (Crustacea: decapoda). Physiol Biochem Zool 73: 406‐415, 2000.
 200.Fritsche R, Schwerte T, Pelster B. Nitric oxide and vascular reactivity in developing zebrafish, Danio rerio. Am J Physiol Regul Integr Comp Physiol 279: R2200‐R2207, 2000.
 201.Fukuda N, Wu Y, Farman G, Irving TC, Granzier H. Titin‐based modulation of active tension and interfilament lattice spacing in skinned rat cardiac muscle. Pflugers Arch 449: 449‐457, 2005.
 202.Gadalla MM, Snyder SH. Hydrogen sulfide as a gasotransmitter. J Neurochem 113: 14‐26, 2010.
 203.Galli GL, Skovgaard N, Abe AS, Taylor EW, Conlon JM, Wang T. Cardiovascular actions of rattlesnake bradykinin ([Val1,Thr6]bradykinin) in the anesthetized South American rattlesnake Crotalus durissus terrificus. Am J Physiol Regul Integr Comp Physiol 288: R456‐R465, 2005.
 204.Galli GL, Skovgaard N, Abe AS, Taylor EW, Wang T. The role of nitric oxide in the regulation of the systemic and pulmonary vasculature of the rattlesnake, Crotalus durissus terrificus. J Comp Physiol [B] 175: 201‐208, 2005.
 205.Galli GL, Taylor EW, Shiels HA. Calcium flux in turtle ventricular myocytes. Am J Physiol Regul Integr Comp Physiol 291: R1781‐R1789, 2006.
 206.Gamperl A, Pinder A, Boutilier R. Effect of coronary ablation and adrenergic stimulation on in vivo cardiac performance in trout (Oncorhynchus mykiss). J Exp Biol 186: 127‐143, 1994.
 207.Gamperl A, Pinder A, Grant R, Boutilier R. Influence of hypoxia and adrenaline administration on coronary blood flow and cardiac performance in seawater rainbow trout (Oncorhynchus mykiss). J Exp Biol 193: 209‐232, 1994.
 208.Gamperl AK, Axelsson M, Farrell AP. Effects of swimming and environmental hypoxia on coronary blood flow in rainbow trout. Am J Physiol Regul Integr Comp Physiol 269: R1258‐R1266, 1995.
 209.Gao WD, Backx PH, Azan‐Backx M, Marban E. Myofilament Ca2+ sensitivity in intact versus skinned rat ventricular muscle. Circ Res 74: 408‐415, 1994.
 210.Ge RL, Kubo K, Kobayashi T, Sekiguchi M, Honda T. Blunted hypoxic pulmonary vasoconstrictive response in the rodent Ochotona curzoniae (pika) at high altitude. Am J Physiol Heart Circ Physiol 274: H1792‐H1799, 1998.
 211.Gesser H, Andresen P, Brams P, Sund‐Laursen J. Inotropic effects of adrenaline on the anoxic or hypercapnic myocardium of rainbow trout and eel. J Comp Physiol 147: 123‐128, 1982.
 212.Gillis TE, Marshall CR, Tibbits GF. Functional and evolutionary relationships of troponin C. Physiol Genom 32: 16‐27, 2007.
 213.Gillis TE, Marshall CR, Xue X‐H, Borgford TJ, Tibbits GF. Ca2+ binding to cardiac troponin C: Effects of temperature and pH on mammalian and salmonid isoforms. Am J Physiol Regul Integr Comp Physiol 279: R1707‐R1715, 2000.
 214.Gillis TE, Tibbits GF. Beating the cold: the functional evolution of troponin C in teleost fish. Comp Biochem Physiol A Mol Integr Physiol 132: 763‐772, 2002.
 215.Gisolf J, Gisolf A, van Lieshout JJ, Karemaker JM. The siphon controversy: An integration of concepts and the brain as baffle. Am J Physiol Regul Integr Comp Physiol 289: R627‐R629, 2005.
 216.Gladfelter EH. Circulation of fluids in the gastrovascular system of the reef coral Acropora cervicornis. Biol Bull 165: 619‐636, 1983.
 217.Gleeson TT. Patterns of metabolic recovery from exercise in amphibians and reptiles. J Exp Biol 160: 187‐207, 1991.
 218.Gleeson TT, Mitchell GS, Bennett AF. Cardiovascular responses to graded activity in the lizards Varanus and Iguana. Am J Physiol Regul Integr Comp Physiol 239: R174‐R179, 1980.
 219.Gleeson TT, Mullin WJ, Baldwin KM. Cardiovascular responses to treadmill exercise in rats: Effects of training. J Appl Physiol 54: 789‐793, 1983.
 220.Goetz RH. Preliminary observations on the circulation in the giraffe. Trans Am Coll Cardiol 5: 239‐248, 1955.
 221.Goetz RH, Keen EN. Some aspects of the cardiovascular system in the giraffe. Angiology 8: 542‐564, 1957.
 222.Goetz RH, Warren JV, Gauer OH, Patterson JL, Jr., Doyle JT, Keen EN, McGregor M. Circulation of the giraffe. Circ Res 8: 1049‐1058, 1960.
 223.Gollock MJ, Currie S, Petersen LH, Gamperl AK. Cardiovascular and haematological responses of Atlantic cod (Gadus morhua) to acute temperature increase. J Exp Biol 209: 2961‐2970, 2006.
 224.Goolish EM. Cold‐acclimation increases the ventricle size of carp, Cyprinus carpio. J Therm Biol 12: 203‐205, 1987.
 225.Graham JB, Dickson KA. Tuna comparative physiology. J Exp Biol 207: 4015‐4024, 2004.
 226.Graham M, Farrell A. The effect of temperature acclimation and adrenaline on the performance of a perfused trout heart. Physiol Zool 62: 38‐61, 1989.
 227.Graham M, Farrell A. Environmental influences on cardiovascular variables in rainbow trout, Oncorhynchus mykiss (Walbaum). J Fish Biol 41: 851‐858, 1992.
 228.Grant R, Regnier M. The comparative anatomy of the cardiac coronary vessels. Heart 13: 375‐388, 1926.
 229.Greenaway P, Farrelly C. Vasculature of the gas‐exchange organs in air‐breathing brachyurans. Physiol Zool 63: 117‐139, 1990.
 230.Groves BM, Droma T, Sutton JR, McCullough RG, McCullough RE, Zhuang J, Rapmund G, Sun S, Janes C, Moore LG. Minimal hypoxic pulmonary hypertension in normal Tibetans at 3,658 m. J Appl Physiol 74: 312‐318, 1993.
 231.Grubb B, Mills CD, Colacino JM, Schmidt‐Nielsen K. Effect of arterial carbon dioxide on cerebral blood flow in ducks. Am J Physiol Heart Circ Physiol 232: H596‐H601, 1977.
 232.Grubb BR. Cardiac output and stroke volume in exercising ducks and pigeons. J Appl Physiol 53: 207‐211, 1982.
 233.Grubb BR. Allometric relations of cardiovascular function in birds. Am J Physiol Heart Circ Physiol 245: H567‐H572, 1983.
 234.Grunz H. Amphibian embryos as a model system for organ engineering in vitro induction and rescue of the heart anlage. Int J Dev Biol 43: 361‐364, 1999.
 235.Guyton AC. Blood pressure control–special role of the kidneys and body fluids. Science 252: 1813‐1816, 1991.
 236.Hagensen MK, Abe AS, Falk E, Wang T. Physiological importance of the coronary arterial blood supply to the rattlesnake heart. J Exp Biol 211: 3588‐3593, 2008.
 237.Halasz NA, Elsner R, Garvie RS, Grotke GT. Renal recovery from ischemia: A comparative study of harbor seal and dog kidneys. Am J Physiol 227: 1331‐1335, 1974.
 238.Halpern MH, May MM. Phylogenetic study of the extracardiac arteries to the heart. AM J Anat 102: 469‐480, 1958.
 239.Hammond HK, White FC, Bhargava V, Shabetai R. Heart size and maximal cardiac output are limited by the pericardium. Am J Physiol Heart Circ Physiol 263: H1675‐H1681, 1992.
 240.Hanssen RG, Lafeber FP, Flik G, Wendelaar Bonga SE. Ionic and total calcium levels in the blood of the European eel (Anguilla anguilla): effects of stanniectomy and hypocalcin replacement therapy. J Exp Biol 141: 177‐186, 1989.
 241.Haraldsen L, Soderstrom‐Lauritzsen V, Nilsson GE. Oxytocin stimulates cerebral blood flow in rainbow trout (Oncorhynchus mykiss) through a nitric oxide dependent mechanism. Brain Res 929: 10‐14, 2002.
 242.Hargens AR, Millard RW, Pettersson K, Johansen K. Gravitational haemodynamics and oedema prevention in the giraffe. Nature 329: 59‐60, 1987.
 243.Harrison FW. Microscopic Anatomy of Invertebrates. New York: Wiley‐Liss, 1992.
 244.Harrison R, Tomlinson J. Observations on the venous system in certain Pinnipedia and Cetacea. Proc Zoologic Soc Lond, 205‐234, 1956.
 245.Harrison SM, Bers DM. Influence of temperature on the calcium sensitivity of the myofilaments of skinned ventricular muscle from the rabbit. J Gen Physiol 93: 411‐428, 1989.
 246.Harrison SM, Bers DM. Modification of temperature dependence of myofilament Ca sensitivity by troponin C replacement. Am J Physiol Cell Physiol 258: C282‐C288, 1990.
 247.Harrison SM, Bers DM. Temperature dependence of myofilament Ca sensitivity of rat, guinea pig, and frog ventricular muscle. Am J Physiol Cell Physiol 258: C274‐C281, 1990.
 248.Hartenstein V, Mandal L. The blood/vascular system in a phylogenetic perspective. Bioessays 28: 1203‐1210, 2006.
 249.Hawkes LA, Balachandran S, Batbayar N, Butler PJ, Chua B, Douglas DC, Frappell PB, Hou Y, Milsom WK, Newman SH, Prosser DJ, Sathiyaselvam P, Scott GR, Takekawa JY, Natsagdorj T, Wikelski M, Witt MJ, Yan B, Bishop CM. The paradox of extreme high‐altitude migration in bar‐headed geese Anser indicus. Proc R Soc B 280: 20122114, 2013.
 250.Hawkes LA, Balachandran S, Batbayar N, Butler PJ, Frappell PB, Milsom WK, Tseveenmyadag N, Newman SH, Scott GR, Sathiyaselvam P, Takekawa JY, Wikelski M, Bishop CM. The trans‐Himalayan flights of bar‐headed geese (Anser indicus). Proc Natl Acad Sci U S A 108: 9516‐9519, 2011.
 251.Hedrick MS, Hancock TV, Hillman SS. Metabolism at the max: How vertebrate organisms respond to physical activity. Compr Physiol 5: 1677‐1703, 2015.
 252.Hedrick MS, Palioca WB, Hillman SS. Effects of temperature and physical activity on blood flow shunts and intracardiac mixing in the toad Bufo marinus. Physiol Biochem Zool 72: 509‐519, 1999.
 253.Heistad DD, Kontos HA. Cerebral circulation. Comprehensive Physiology John Wiley & Sons, 2011.
 254.Herreid CF. Hypoxia in invertebrates. Comp Biochem Physiol A Physiol 67: 311‐320, 1980.
 255.Hertel W, Pass G. An evolutionary treatment of the morphology and physiology of circulatory organs in insects. Comp Biochem Physiol A Mol Integr Physiol 133: 555‐575, 2002.
 256.Hicks J, Comeau S. Vagal regulation of intracardiac shunting in the turtle Pseudemys Scripta. J Exp Biol 186: 109‐126, 1994.
 257.Hicks JW, Badeer HS. Siphon mechanism in collapsible tubes: Application to circulation of the giraffe head. Am J Physiol Regul Integr Comp Physiol 256: R567‐R571, 1989.
 258.Hicks JW, Badeer HS. Gravity and the circulation: “Open” vs. “closed” systems. Am J Physiol Regul Integr Comp Physiol 262: R725‐R732, 1992.
 259.Hicks JW, Munis JR. The siphon controversy counterpoint: The brain need not be “baffling”. Am J Physiol Regul Integr Comp Physiol 289: R629‐R632, 2005.
 260.Hill AV, Long C, Lupton H. Muscular exercise, lactic acid, and the supply and utilisation of oxygen. Proc R Soc Lond Ser B 84‐138, 1924.
 261.Hill L. The influence of the force of gravity on the circulation of the blood. J Physiol 18: 15‐53, 1895.
 262.Hillman SS. The effect of anemia on metabolic performance in the frog, rana pipiens. J Exp Zool 211: 107‐111, 1980.
 263.Hillman SS. Cardiac scope in amphibians: Transition to terrestrial life. Can J Zool 69: 2010‐2013, 1991.
 264.Hillman SS, Withers PC, Drewes RC. Correlation of ventricle mass and dehydration tolerance in amphibians. Herpetologica 56: 413‐420, 2000.
 265.Hillman SS, Withers PC, Palioca WB, Ruben JA. Cardiovascular consequences of hypercalcemia during activity in two species of amphibian. J Exp Zool 242: 303‐308, 1987.
 266.Hiroko T, Bunshin L, Ken‐Ichi F. Pulsation rate and oxygen consumption of isolated hearts of the goldfish, Carassius auratus, acclimated to different temperatures. Comp Biochem Physiol A Physiol 82: 281‐283, 1985.
 267.Hoagland TM, Weaver L, Jr., Conlon JM, Wang Y, Olson KR. Effects of endothelin‐1 and homologous trout endothelin on cardiovascular function in rainbow trout. Am J Physiol Regul Integr Comp Physiol 278: R460‐R468, 2000.
 268.Hochachka P. Balancing conflicting metabolic demands of exercise and diving. Fed Proc 45: 2948‐2952, 1986.
 269.Hoit BD, Dalton ND, Erzurum SC, Laskowski D, Strohl KP, Beall CM. Nitric oxide and cardiopulmonary hemodynamics in Tibetan highlanders. J Appl Physiol 99: 1796‐1801, 2005.
 270.Holt JP. The normal pericardium. Am J Cardiol 26: 455‐465, 1970.
 271.Holt JP, Rhode EA, Kines H. Ventricular volumes and body weight in mammals. Am J Physiol 215: 704‐715, 1968.
 272.Hove‐Madsen L. The influence of temperature on ryanodine sensitivity and the force‐frequency relationship in the myocardium of rainbow trout. J Exp Biol 167: 47‐60, 1992.
 273.Hove‐Madsen L, Tort L. L‐type Ca2+ current and excitation‐contraction coupling in single atrial myocytes from rainbow trout. Am J Physiol Regul Integr Comp Physiol 275: R2061‐R2069, 1998.
 274.Howse HD, Ferrans VJ, Hibbs RG. A light and electron microscopic study of the heart of a crayfish, Procambarus clarkii (Giraud). II. Fine structure. J Morphol 133: 353‐373, 1971.
 275.Hryshko LV. The cardiac Na+‐Ca2+ exchanger. Comprehensive Physiology, John Wiley & Sons, 2011.
 276.Hylland P, Nilsson GE. Evidence that acetylcholine mediates increased cerebral blood flow velocity in crucian carp through a nitric oxide–dependent mechanism. J Cereb Blood Flow Metab 15: 519‐524, 1995.
 277.Iijima T. A histochemical study of the innervation of cerebral blood vessels in the turtle. J Comp Neurol 176: 307‐314, 1977.
 278.Iijima T, Wasano T. A histochemical and ultrastructural study of serotonin‐containing nerves in cerebral blood vessels of the lamprey. Anat Rec 198: 671‐680, 1980.
 279.Iijima T, Wasano T, Tagawa T, Ando K. A histochemical study of the innervation of cerebral blood vessels in the snake. Cell Tissue Res 179: 143‐155, 1977.
 280.Irving L, Scholander PF, Grinnell SW. The regulation of arterial blood pressure in the seal during diving. Am J Physiol 135: 557‐566, 1942.
 281.Jackson DC, Ultsch Gr. Long‐term submergence at 3 C of the turtle, Chrysemys picta bellii, in normoxic and severely hypoxic water: II. Extracellular ionic responses to extreme lactic acidosis. J Exp Biol 96: 29‐43, 1982.
 282.Jen SC, Rovainen CM. An adenosine agonist increases blood flow and density of capillary branches in the optic tectum of Xenopus laevis tadpoles. Microcirculation 1: 59‐66, 1994.
 283.Jennings BL, Blake RE, Joss JMP, Donald JA. Vascular distribution of nitric oxide synthase and vasodilation in the Australian lungfish, Neoceratodus forsteri. Comp Biochem Physiol A Mol Integr Physiol 151: 590‐595, 2008.
 284.Jennings BL, Broughton BR, Donald JA. Nitric oxide control of the dorsal aorta and the intestinal vein of the Australian short‐finned eel Anguilla australis. J Exp Biol 207: 1295‐1303, 2004.
 285.Jennings BL, Donald JA. Neurally‐derived nitric oxide regulates vascular tone in pulmonary and cutaneous arteries of the toad, Bufo marinus. Am J Physiol Regul Integr Comp Physiol 295: R1640‐R1646, 2008.
 286.Jennings J. Studies on feeding, digestion, and food storage in free‐living flatworms (Platyhelminthes: Turbellaria). Biol Bull 112: 63‐80, 1957.
 287.Jensen B, Elfwing M, Elsey RM, Wang T, Crossley Ii DA. Coronary blood flow in the anesthetized American alligator (Alligator mississippiensis). Comp Biochem Physiol A Mol Integr Physiol 191: 44‐52, 2016.
 288.Jensen FB. The role of nitrite in nitric oxide homeostasis: A comparative perspective. Biochim Biophys Acta 1787: 841‐848, 2009.
 289.Jespersen Å, Lützen J. Ultrastructure of the nephridio‐circulatory connections in Tubulanus annulatus (Nemertini, Anopla). Zoomorphology 107: 181‐189, 1987.
 290.Johansen K. Circulation in the hagfish, Myxine glutinosa L. Biol Bull 118: 289‐295, 1960.
 291.Johansen K. Heart and circulation in gill, skin and lung breathing. Respiry Physiol 14: 193‐210, 1972.
 292.Johansen K, Burggren, WW. Cardiovascular function in lower vertebrates. In: Bourne G, editor. Hearts and Heart‐like Organs. New York: Academic Press, 1980, pp. 61‐117.
 293.Johansen K, Martin AW. Circulation in a giant earthworm, Glossoscolex giganteus. J Exp Biol 45: 165‐172, 1966.
 294.Johansen K, Reite OB. Influence of acetylcholine and biogenic amines on branchial, pulmonary and systemic vascular resistance in the African lungfish, Protopterus aethiopicus. Acta Physiol Scand 74: 465‐471, 1968.
 295.Johnson RL, Heigenhauser GJ, Hsia CC, Jones NL, Wagner PD. Determinants of gas exchange and acid–base balance during exercise. Compr Physiol 2011.
 296.Jones DR, Brill RW, Mense DC. The influence of blood gas properties on gas tensions and pH of ventral and dorsal aortic blood in free‐swimming tuna, Euthynnus affinis. J Exp Biol 120: 201‐213, 1986.
 297.Jones DR, Fisher HD, McTaggart S, West NH. Heart rate during breath‐holding and diving in the unrestrained harbor seal (Phoca vitulina richardi). Can J Zool 51: 671‐680, 1973.
 298.Jones DR, Randall DJ. The respiratory and circulatory systems during exercise. In: Hoar WS, Randall DJ, editors. Fish Physiology: Locomotion. New York: Academic, 1979, pp. 425‐501.
 299.Jones JH, Longworth KE, Lindholm A, Conley KE, Karas RH, Kayar SR, Taylor CR. Oxygen transport during exercise in large mammals. I. Adaptive variation in oxygen demand. J Appl Physiol 67: 862‐870, 1989.
 300.Juhasz‐Nagy A, Szentivanyi M, Szabo M, Vamosi B. Coronary circulation of the tortoise heart. Acta Physiol Acad Sci Hung 23: 33‐48, 1963.
 301.Kamm RD, Pedley TJ. Flow in collapsible tubes: A brief review. J Biomech Eng 111: 177‐179, 1989.
 302.Katz A. Interplay between inotropic and lusitropic effects of cyclic adenosine monophosphate on the myocardial cell. Circulation 82: I7‐I11, 1990.
 303.Katz AM. Regulation of cardiac muscle contractility. J Gen Physiol 50: 185‐196, 1967.
 304.Keen J, Farrell A, Tibbits G, Brill R. Cardiac physiology in tunas. II. Effect of ryanodine, calcium, and adrenaline on force‐frequency relationships in atrial strips from skipjack tuna, Katsuwonus pelamis. Can J Zool 70: 1211‐1217, 1992.
 305.Keen J, Vianzon D‐M, Farrell A, Tibbits G. Effect of temperature and temperature acclimation on the ryanodine sensitivity of the trout myocardium. J Comp Physiol [B] 164: 438‐443, 1994.
 306.Ken‐Ichi Y. Contraction of spleen in exercised freshwater teleost. Comp Biochem Physiol A Physiol 89: 65‐66, 1988.
 307.Ken‐ichi Y, Yasuo I. Erythrocyte supply from the spleen of exercised carp. Comp Biochem Physiol A Physiol 92: 139‐144, 1989.
 308.Kennedy JW, Baxley WA, Figley MA, Dodge HT, Blackmon JR. Quantitative angiocardiography I. The normal left ventricle in man. Circulation 34: 272‐278, 1966.
 309.Kent J, Koban M, Prosser CL. Cold‐acclimation‐induced protein hypertrophy in channel catfish and green sunfish. J Comp Physiol [B] 158: 185‐198, 1988.
 310.Kiceniuk JW, Jones DR. The oxygen transport system in trout (Salmo gairdneri) during sustained exercise. J Exp Biol 69: 247‐260, 1977.
 311.Kieffer JD. Perspective–Exercise in fish: 50+years and going strong. Comp Biochem Physiol A Mol Integr Physiol 156: 163‐168, 2010.
 312.Kimani JK, Mungai JM. Observations on the structure and innervation of the presumptive carotid sinus area in the giraffe (Giraffa camelopardalis). Acta Anatomica (Basel) 115: 117‐133, 1983.
 313.Kimani JK, Opole IO. The structural organization and adrenergic innervation of the carotid arterial system of the giraffe (Giraffa camelopardalis). Anat Rec 230: 369‐377, 1991.
 314.Kimani JK, Opole IO, Ogeng'o JA. Structure and sympathetic innervation of the intracranial arteries in the giraffe (Giraffa camelopardalis). J Morphol 208: 193‐203, 1991.
 315.Kimura H. Hydrogen sulfide induces cyclic AMP and modulates the NMDA receptor. Biochem Biophys Res Commun 267: 129‐133, 2000.
 316.Kitoh K, Oguri M. Differentiation of the compact layer in the heart ventricle of rainbow trout. Bull Jpn Soc Sci Fish 51: 539‐542, 1985.
 317.Klabunde R. Cardiovascular Physiology Concepts. Philadelphia: Lippincott Williams & Wilkins, 2011.
 318.Kluthe GJ, Hillman SS. Cardiac performance correlates of relative heart ventricle mass in amphibians. J Comp Physiol [B] 183: 801‐809, 2013.
 319.Knight GE, Burnstock G. Responses of the aorta of the garter snake (Thamnophis sirtalis parietalis) to purines. Br J Pharmacol 114: 41‐48, 1995.
 320.Knight GE, Burnstock G. Identification of P1 and P2 purinoceptors in the aorta of the lizard (Agama sp.). Comp Biochem Physiol C Toxicol Pharmacol 128: 413‐423, 2001.
 321.Kolok AS, Spooner MR, Farrell AP. The effect of exercise on the cardiac output and blood flow distribution of the largescale sucker Catostomus macrocheilus. J Exp Biol 183: 301‐321, 1993.
 322.Kooyman G, Campbell W. Heart rates in freely diving Weddell seals, Leptonychotes weddelli. Comp Biochem Physiol A Physiol 43: 31‐36, 1972.
 323.Kopp R, Schwerte T, Pelster B. Cardiac performance in the zebrafish breakdance mutant. J Exp Biol 208: 2123‐2134, 2005.
 324.Korner P, Shaw J, West M, Oliver J. Central nervous system control of baroreceptor reflexes in the rabbit. Circ Res 31: 637‐652, 1972.
 325.Korsmeyer K, Dewar H, Lai N, Graham J. The aerobic capacity of tunas: Adaptation for multiple metabolic demands. Comp Biochem Physiol A Physiol 113: 17‐24, 1996.
 326.Krosniunas EH, Gerstner GE. A model of vertebrate resting metabolic rate: Balancing energetics and O2 transport in system design. Respir Physiol Neurobiol 134: 93‐113, 2003.
 327.Kuo L, Chilian WM, Davis MJ. Coronary arteriolar myogenic response is independent of endothelium. Circ Res 66: 860‐866, 1990.
 328.Kuramoto T, Ebara A. Effects of perfusion pressure on the bursting neurones in the intact or segmented cardiac ganglion of the lobster, Panulirus japonicus. J Neurosci Res 13: 569‐580, 1985.
 329.Kuramoto T, Ebara A. Combined effects of 5‐hydroxytryptamine and filling pressure on the isolated heart of the lobster, Panulirus japonicus. J Comp Physiol [B] 158: 403‐412, 1988.
 330.Kuramoto T, Kuwasawa K. Ganglionic activation of the myocardium of the lobster, Panulirus japonicus. J Comp Physiol 139: 67‐76, 1980.
 331.Kuramoto T, Wilkens JL, McMahon BR. Neural control of cardiac outflow through the sternal valve in the lobster Homarus americanus. Physiol Zool 443‐452, 1995.
 332.Kuramoto T, Yamagishi H. Physiological anatomy, burst formation, and burst frequency of the cardiac ganglion of crustaceans. Physiol Zool 102‐116, 1990.
 333.Kusaba H, Ando K, Fujihara N. Innervation pattern of substance P‐ and calcitonin gene‐related peptide‐immunoreactive nerves of the cerebral arteries in the quail. J Vet Med Sci 62: 595‐602, 2000.
 334.Kusaba H, Andō K, Noboru M, Hayashi K, Fujihara N, Iwamoto H. Comparative study of the innervation of acetylcholinesterase‐positive nerves in the cerebral arterial tree of birds. Anim Sci J 73: 143‐147, 2002.
 335.Lai NC, Dalton N, Lai YY, Kwong C, Rasmussen R, Holts D, Graham JB. A comparative echocardiographic assessment of ventricular function in five species of sharks. Comp Biochem Physiol A Mol Integr Physiol 137: 505‐521, 2004.
 336.Lai NC, Graham JB, Bhargava V, Shabetai R. Mechanisms of venous return and ventricular filling in elasmobranch fish. Am J Physiol Heart Circ Physiol 270: H1766‐H1771, 1996.
 337.Lai NC, Graham JB, Lowell WR, Shabetai R. Elevated pericardial pressure and cardiac output in the leopard shark Triakis semifasciata during exercise: The role of the pericardioperitoneal canal. J Exp Biol 147: 263‐277, 1989.
 338.Lai NC, Shabetai R, Graham JB, Hoit BD, Sunnerhagen KS, Bhargava V. Cardiac function of the leopard shark, Triakis semifasciata. J Comp Physiol [B] 160: 259‐268, 1990.
 339.Langenbruch P‐F, Weissenfels N. Canal systems and choanocyte chambers in freshwater sponges (Porifera, Spongillidae). Zoomorphology 107: 11‐16, 1987.
 340.Langer G. Calcium and the heart: Exchange at the tissue, cell, and organelle levels. FASEB J 6: 893‐902, 1992.
 341.Langille BL, Jones DR. Dynamics of blood flow through the hearts and arterial systems of anuran amphibia. J Exp Biol 68: 1‐17, 1977.
 342.Lasiewski RC, Calder WA, Jr. A preliminary allometric analysis of respiratory variables in resting birds. Respir Physiol 11: 152‐166, 1971.
 343.Lassen NA. Cerebral blood flow and oxygen consumption in man. Pharmacol Rev 39: 183‐238, 1959.
 344.Laurent P, Holmgren S, Nilsson S. Nervous and humoral control of the fish heart: Structure and function. Comp Biochem Physiol A Physiol 76: 525‐542, 1983.
 345.Lawn ID, Mackie GO, Silver G. Conduction system in a sponge. Science 211: 1169‐1171, 1981.
 346.Laybourne RC. Collision between a vulture and an aircraft at an altitude of 37,000 feet. Wilson Bull 461‐462, 1974.
 347.Lazou A, Beis I. Effects of adenosine perfusion on the metabolism and contractile activity of Rana ridibunda heart. Comp Biochem Physiol C Pharmacol Toxicol Endocrinol 86: 415‐419, 1987.
 348.Levine HJ. Compliance of the left ventricle. Circulation 46: 423‐426, 1972.
 349.Lewis J, Price W. Feeding mechanisms and feeding strategies of Atlantic reef corals. J Zool 176: 527‐544, 1975.
 350.Li Z, Smith MP, Duff DW, Barton BA, Olson KR, Conlon JM. Purification and cardiovascular activity of [Met1, Met5]‐bradykinin from the plasma of a sturgeon (Acipenseriformes). Peptides 19: 635‐641, 1998.
 351.Lillywhite HB, Donald JA. Pulmonary blood flow regulation in an aquatic snake. Science 245: 293‐295, 1989.
 352.Linden RJ. The size of the heart. Cardioscience 5: 225‐233, 1994.
 353.Lipscombe D, Helton TD, Xu W. L‐type calcium channels: The low down. J Neurophysiol 92: 2633‐2641, 2004.
 354.Listerman LR, Deskins J, Bradacs H, Cooper RL. Heart rate within male crayfish: Social interactions and effects of 5‐HT. Comp Biochem Physiol A Mol Integr Physiol 125: 251‐263, 2000.
 355.MacGregor DC, Covell JW, Mahler F, Dilley RB, Ross J. Relations between afterload, stroke volume, and descending limb of Starlings curve. Am J Physiol 227: 884‐890, 1974.
 356.MacKinnon MR, Heatwole H. Comparative cardiac anatomy of the reptilia. IV. The coronary arterial circulation. J Morphol 170: 1‐27, 1981.
 357.Magnan A. Les Caractéristiques des Oiseaux Suivant le Mode de Vol: Leur Application a la Construction des Avions. France: Masson, 1922.
 358.Maina JN. Structure, function and evolution of the gas exchangers: Comparative perspectives. J Anat 201: 281‐304, 2002.
 359.Maina JN, West JB. Thin and strong! The bioengineering dilemma in the structural and functional design of the blood‐gas barrier. Pharmacol Rev 85: 811‐844, 2005.
 360.Malvin G, Macias S, Sanchez M, Dasalla R, Park A, Duran M. Lymphatic regulation of hematocrit during hypoxia in the toad Bufo woodhousei. Am J Physiol Regul Integr Comp Physiol 269: R814‐R821, 1995.
 361.Malvin GM, Hicks JW, Greene ER. Central vascular flow patterns in the alligator Alligator mississipiensis. Am J Physiol Regul Integr Comp Physiol 269: R1133‐R1139, 1995.
 362.Mangum C, Van Winkle W. Responses of aquatic invertebrates to declining oxygen conditions. Amer Zool 13: 529‐541, 1973.
 363.Mangum CP. Oxygen transport in invertebrates. Am J Physiol Regul Integr Comp Physiol 248: R505‐R514, 1985.
 364.Marban E, Rink TJ, Tsien RW, Tsien RY. Free calcium in heart muscle at rest and during contraction measured with Ca2+‐sensitive microelectrodes. Nature 286(5776): 845‐850, 1980.
 365.Markina‐Palashchenko LD. Cholinergic and adrenergic innervation of the arteries of the base of the brain in certain lower vertebrates. Arkh Anat Gistol Embriol 77: 16‐24, 1979.
 366.Marsh RL, Ellerby DJ. Partitioning locomotor energy use among and within muscles Muscle blood flow as a measure of muscle oxygen consumption. J Exp Biol 209: 2385‐2394, 2006.
 367.Martinez‐Lemus LA, Hester RK, Becker EJ, Jeffrey JS, Odom TW. Pulmonary artery endothelium‐dependent vasodilation is impaired in a chicken model of pulmonary hypertension. Am J Physiol Regul Integr Comp Physiol 277: R190‐R197, 1999.
 368.Mauceri A, Fasulo S, Ainis L, Licata A, Lauriano ER, Martinez A, Mayer B, Zaccone G. Neuronal nitric oxide synthase (nNOS) expression in the epithelial neuroendocrine cell system and nerve fibers in the gill of the catfish, Heteropneustes fossilis. Acta Histochem 101: 437‐448, 1999.
 369.Maynard DM. Circulation and heart function. The Physiology of Crustaceans 1: 161‐226, 1960.
 370.McCalden TA, Borsook D, Mendelow AD, Shimell CJ, de Vos V, Pieterse PC, de Klerk B. Autoregulation and haemodynamics of giraffe carotid blood flow. S Afr J Sci 73: 278‐279, 1977.
 371.McDermott JJ, Roe P. Food, feeding behavior and feeding ecology of nemerteans. Amer Zool 25: 113‐125, 1985.
 372.McDonald BI, Ponganis PJ. Insights from venous oxygen profiles: Oxygen utilization and management in diving California sea lions. J Exp Biol 216: 3332‐3341, 2013.
 373.McDonald TF, Cavalié A, Trautwein W, Pelzer D. Voltage‐dependent properties of macroscopic and elementary calcium channel currents in guinea pig ventricular myocytes. Pflugers Arch 406: 437‐448, 1986.
 374.McGaw I, Airriess C, McMahon B. Peptidergic modulation of cardiovascular dynamics in the Dungeness crab, Cancer magister. J Comp Physiol [B] 164: 103‐111, 1994.
 375.McGaw IJ. Does feeding limit cardiovascular modulation in the Dungeness crab, Cancer magister during hypoxia. J Exp Biol 208: 83‐91, 2005.
 376.McGaw IJ, McMahon BR. Balancing tissue perfusion demands: cardiovascular dynamics of Cancer magister during exposure to low salinity and hypoxia. J Exp Zool A 295: 57‐70, 2003.
 377.McGaw IJ, Reiber CL. Cardiovascular system of the blue crab Callinectes sapidus. J Morphol 251: 1‐21, 2002.
 378.McMahon B, Reiber C, Burggren W. Arterial blood flows in normoxic and hypoxic lobster, Homarus americanus. Amer Zool A53, 1989.
 379.McMahon B, Wilkens J. Ventilation, perfusion and oxygen uptake. The Biology of Crustacea 5: 289‐372, 1983.
 380.McMahon BR, Burnett LE. The crustacean open circulatory system: A reexamination. Physiol Zool 35‐71, 1990.
 381.McMahon BR, Wilkens JL, Smith PJS. Invertebrate circulatory systems. Comprehensive Physiology, John Wiley & Sons, 2010.
 382.Meghji P, Burnstock G. The effects of adenyl compounds on the heart of the axolotl (Ambystoma mexicanum). Comp Biochem Physiol C Pharmacol Toxicol Endocrinol 76: 319‐326, 1983.
 383.Meir JU, Champagne CD, Costa DP, Williams CL, Ponganis PJ. Extreme hypoxemic tolerance and blood oxygen depletion in diving elephant seals. Am J Physiol Regul Integr Comp Physiol 297: R927‐R939, 2009.
 384.Meir JU, Ponganis PJ. High‐affinity hemoglobin and blood oxygen saturation in diving emperor penguins. J Exp Biol 212: 3330‐3338, 2009.
 385.Meis L, Vianna AL. Energy interconversion by the Ca2+‐dependent ATPase of the sarcoplasmic reticulum. Annu Rev Biochem 48: 275‐292, 1979.
 386.Mellish J, Pinder A, Smith S. You've got to have heart… or do you. Axolotl Newsletter 23: 34‐38, 1994.
 387.Mendonça PC, Gamperl AK. The effects of acute changes in temperature and oxygen availability on cardiac performance in winter flounder (Pseudopleuronectes americanus). Comp Biochem Physiol A Mol Integr Physiol 155: 245‐252, 2010.
 388.Mesquita LS, Frias FT, Carmona E, Borgheresi RA. Differences in endothelin receptor types in the vasculature of Bothrops jararaca (Viperidae) and Oxyrhopus guibei (Colubridae) snakes. Comp Biochem Physiol C Pharmacol Toxicol Endocrinol 148: 61‐67, 2008.
 389.Mess AM, Ferner KJ. Evolution and development of gas exchange structures in Mammalia: The placenta and the lung. Respir Physiol Neurobiol 173: S74‐S82, 2010.
 390.Meyer J, Lentz CW, Herndon DN, Nelson S, Traber LD, Traber DL. Effects of halothane anesthesia on vasoconstrictor response to NG‐nitro‐L‐arginine methyl ester, an inhibitor of nitric oxide synthesis, in sheep. Anesth Analg 77: 1215‐1221, 1993.
 391.Milsom WK, Langille BL, Jones DR. Vagal control of pulmonary vascular resistance in the turtle Chrysemys scripta. Can J Zool 55: 359‐367, 1977.
 392.Minerick AR, Chang H‐C, Hoagland TM, Olson KR. Dynamic synchronization analysis of venous pressure‐driven cardiac output in rainbow trout. Am J Physiol Regul Integr Comp Physiol 285: R889‐R896, 2003.
 393.Mirceta S, Signore AV, Burns JM, Cossins AR, Campbell KL, Berenbrink M. Evolution of mammalian diving capacity traced by myoglobin net surface charge. Science 340: 1234192, 2013.
 394.Mitchell G, Bobbitt JP, Devries S. Cerebral perfusion pressure in giraffe: Modelling the effects of head‐raising and ‐lowering. J Theor Biol 252: 98‐108, 2008.
 395.Mitchell G, Skinner J. How giraffe adapt to their extraordinary shape. Transactions of the Royal Society of South Africa 48: 207‐218, 1993.
 396.Mitchell G, Skinner J. Giraffe thermoregulation: A review. Trans R Soc South Africa 59: 109‐118, 2004.
 397.Mitchell G, Skinner JD. An allometric analysis of the giraffe cardiovascular system. Comp Biochem Physiol A Mol Integr Physiol 154: 523‐529, 2009.
 398.Møller‐Nielsen T, Gesser H. Sarcoplasmic reticulum and excitation‐contraction coupling at 20 and 10 C in rainbow trout myocardium. J Comp Physiol [B] 162: 526‐534, 1992.
 399.Moncada S, Palmer RM, Higgs EA. Nitric oxide: Physiology, pathophysiology, and pharmacology. Pharmacol Rev 43: 109‐142, 1991.
 400.Monge C, Leon‐Velarde F. Physiological adaptation to high altitude: Oxygen transport in mammals and birds. Pharmacol Rev 71: 1135‐1172, 1991.
 401.Moore J, Gibson R. The evolution and comparative physiology of terrestrial and freshwater nemerteans. Biologic Rev 60: 257‐312, 1985.
 402.Morita‐Tsuzuki Y, Bouskela E, Hardebo J. Effects of nitric oxide synthesis blockade and angiotensin II on blood flow and spontaneous vasomotion in the rat cerebral microcirculation. Acta Physiol Scand 148: 449‐454, 1993.
 403.Moss RL, Buck SH. Regulation of cardiac contraction by calcium. Comprehensive Physiology, John Wiley & Sons, 2011.
 404.Mubagwa K, Mullane K, Flameng W. Role of adenosine in the heart and circulation. Cardiovasc Res 32: 797‐813, 1996.
 405.Munch G, Svendsen J, Damsgaard R, Secher N, González‐Alonso J, Mortensen S. Maximal heart rate does not limit cardiovascular capacity in healthy humans: Insight from right atrial pacing during maximal exercise. J Physiol 592: 377‐390, 2014.
 406.Munns SL, Hartzler LK, Bennett AF, Hicks JW. Elevated intra‐abdominal pressure limits venous return during exercise in Varanus exanthematicus. J Exp Biol 207: 4111‐4120, 2004.
 407.Munns SL, Hartzler LK, Bennett AF, Hicks JW. Terrestrial locomotion does not constrain venous return in the American alligator, Alligator mississippiensis. J Exp Biol 208: 3331‐3339, 2005.
 408.Muñoz‐Chápuli R, Carmona R, Guadix J, Macías D, Pérez‐Pomares J. The origin of the endothelial cells: An evo‐devo approach for the invertebrate/vertebrate transition of the circulatory system. Evol Develop 7: 351‐358, 2005.
 409.Mustafa T, Agnisola C. Vasoactivity of adenosine in the trout (Oncorhynchus mykiss) coronary system: Involvement of nitric oxide and interaction with noradrenaline. J Exp Biol 201(Pt 22): 3075‐3083, 1998.
 410.Mustafa T, Agnisola C. Vasoactivity of prostanoids in the trout (Oncorhynchus mykiss) coronary system: Modification by noradrenaline. Fish Physiol Biochem 13: 249‐261, 1994.
 411.Mykles DL, Adams ME, Gade G, Lange AB, Marco HG, Orchard I. Neuropeptide action in insects and crustaceans. Physiol Biochem Zool 83: 836‐846, 2010.
 412.Nielsen KE, Gesser H. Effects of [Ca2+] on contractility in the anoxic cardiac muscle of mammal and fish. Life Sci 32: 1437‐1442, 1983.
 413.Nikam TB, Khole VV. Insect Spiracular Systems. Ellis Horwood Limited, 1989.
 414.Nilsson S, Holmgren S. Comparative physiology and evolution of the autonomic nervous system. The autonomic nervous system, Vol. 4. Chur, Switzerland, USA: Harwood Academic Publishers, 1994.
 415.Nilsson O, Bööj S, Dahlström A, Hargens A, Millard R, Pettersson K. Sympathetic innervation of the cardiovascular system in the giraffe. J Vasc Res 25: 299‐307, 1988.
 416.Nilsson S. Autonomic Nerve Function in the Vertebrates. Berlin, New York: Springer‐Verlag, 1983.
 417.Nilsson S, Grove DJ. Adrenergic and cholinergic innervation of the spleen of the cod: Gadus morhua. Eur J Pharmacol 28: 135‐143, 1974.
 418.Nilsson S, Sundin L. Gill blood flow control. Comp Biochem Physiol A Mol Integr Physiol 119: 137‐147, 1998.
 419.Nishiwaki K, Nyhan DP, Rock P, Desai PM, Peterson WP, Pribble CG, Murray PA. N omega‐nitro‐L‐arginine and pulmonary vascular pressure‐flow relationship in conscious dogs. Am J Physiol Heart Circ Physiol 262: H1331‐H1337, 1992.
 420.Noren SR, Kendall T, Cuccurullo V, Williams TM. The dive response redefined: Underwater behavior influences cardiac variability in freely diving dolphins. J Exp Biol 215: 2735‐2741, 2012.
 421.Nowycky MC, Fox AP, Tsien RW. Three types of neuronal calcium channel with different calcium agonist sensitivity. Nature 316: 440‐443, 1985.
 422.Okada J, Kuwasawa K, Kihara A, Tsukamoto YF, Yazawa T. Cholinergic inhibitory innervation of the cardioarterial valves in the isopod Bathynomus doederleini. Zoolog Sci 14: 571‐579, 1997.
 423.Okuno T, Yabuki A, Shiraishi M, Obi T, Miyamoto A. Histamine‐induced modulation of vascular tone in the isolated chicken basilar artery: A possible involvement of endothelium. Comp Biochem Physiol C Pharmacol Toxicol Endocrinol 147: 339‐344, 2008.
 424.Olson KR. Gill circulation: Regulation of perfusion distribution and metabolism of regulatory molecules. J Exp Zool 293: 320‐335, 2002.
 425.Olson KR, Conklin DJ, Weaver L, Jr., Duff DW, Herman CA, Wang X, Conlon JM. Cardiovascular effects of homologous bradykinin in rainbow trout. Am J Physiol Regul Integr Comp Physiol 272: R1112‐R1120, 1997.
 426.Olson KR, Donald JA. Nervous control of circulation–the role of gasotransmitters, NO, CO, and H2S. Acta Histochem 111: 244‐256, 2009.
 427.Olson KR, Forgan LG, Dombkowski RA, Forster ME. Oxygen dependency of hydrogen sulfide‐mediated vasoconstriction in cyclostome aortas. J Exp Biol 211: 2205‐2213, 2008.
 428.Opie L. Physiology and metabolism. The Heart, New York: Raven, 1991, pp. 208‐246.
 429.Orchard CH, Lakatta EG. Intracellular calcium transients and developed tension in rat heart muscle. A mechanism for the negative interval‐strength relationship. J Gen Physiol 86: 637‐651, 1985.
 430.Ostergaard KH, Baandrup UT, Wang T, Bertelsen MF, Andersen JB, Smerup M, Nyengaard JR. Left ventricular morphology of the giraffe heart examined by stereological methods. Anat Rec 296: 611‐621, 2013.
 431.Packard A. Cephalopods and fish: The limits of convergence. Biologic Rev 47: 241‐307, 1972.
 432.Page E, McCallister L, Power B. Stereological measurements of cardiac ultrastructures implicated in excitation‐contraction coupling. Proc Natl Acad Sci U S A 68: 1465‐1466, 1971.
 433.Page SG, Niedergerke R. Structures of physiological interest in the frog heart ventricle. J Cell Sci 11: 179‐203, 1972.
 434.Palmer BM, Noguchi T, Wang Y, Heim JR, Alpert NR, Burgon PG, Seidman CE, Seidman JG, Maughan DW, LeWinter MM. Effect of cardiac myosin binding protein‐C on mechanoenergetics in mouse myocardium. Circ Res 94: 1615‐1622, 2004.
 435.Palumbi SR. How body plans limit acclimation: Responses of a demosponge to wave force. Ecology 74: 208‐214, 1986.
 436.Park KH, Rubin LE, Gross SS, Levi R. Nitric oxide is a mediator of hypoxic coronary vasodilatation. Relation to adenosine and cyclooxygenase‐derived metabolites. Circ Res 71: 992‐1001, 1992.
 437.Parmley W, Sonnenblick E. Relation between mechanics of contraction and relaxation in mammalian cardiac muscle. Am J Physiol 215(5):1084‐1091, 1969.
 438.Pasquis P, Lacaisse A, Dejours P. Maximal oxygen uptake in four species of small mammals. Respir Physiol 9: 298‐309, 1970.
 439.Patey CP, Driedzic WR. Cold acclimation increases activities of mitochondrial long‐chain acyl‐CoA synthetase and carnitine acyl‐CoA transferase I in heart of rainbow trout (Oncorhynchus mykiss). Can J Zool 75: 324‐331, 1997.
 440.Patrick SM, Hoskins AC, Kentish JC, White E, Shiels HA, Cazorla O. Enhanced length‐dependent Ca2+ activation in fish cardiomyocytes permits a large operating range of sarcomere lengths. J Mol Cell Cardiol 48: 917‐924, 2010.
 441.Pavlov NA, Krivchenko AI, Cherepivskaia EN, Zagvazdin Iu S, Zaiats ND. [Vascular reactivity of the brain in the pigeon Columba livia]. Zh Evol Biokhim Fiziol 23: 624‐628, 1987.
 442.Pearson M, Stevens ED. Splenectomy impairs aerobic swim performance in trout. Can J Zool 69: 2089‐2092, 1991.
 443.Pedley TJ. Longitudinal tension variation in collapsible channels: A new mechanism for the breakdown of steady flow. J Biomech Eng 114: 60‐67, 1992.
 444.Pedley TJ, Brook BS, Seymour RS. Blood pressure and flow rate in the giraffe jugular vein. Philos Trans R Soc Lond B Biol Sci 351: 855‐866, 1996.
 445.Pellegrino D, Tota B, Randall D. Adenosine/nitric oxide crosstalk in the branchial circulation of Squalus acanthias and Anguilla anguilla. Comp Biochem Physiol A Mol Integr Physiol 142: 198‐204, 2005.
 446.Pelster B, Burggren WW. Disruption of hemoglobin oxygen transport does not impact oxygen‐dependent physiological processes in developing embryos of zebra fish (Danio rerio). Circ Res 79: 358‐362, 1996.
 447.Peters GW, Steiner DA, Rigoni JA, Mascilli AD, Schnepp RW, Thomas SP. Cardiorespiratory adjustments of homing pigeons to steady wind tunnel flight. J Exp Biol 208: 3109‐3120, 2005.
 448.Petersen KK, Horlyck A, Ostergaard KH, Andresen J, Broegger T, Skovgaard N, Telinius N, Laher I, Bertelsen MF, Grondahl C, Smerup M, Secher NH, Brondum E, Hasenkam JM, Wang T, Baandrup U, Aalkjaer C. Protection against high intravascular pressure in giraffe legs. Am J Physiol Regul Integr Comp Physiol 305: R1021‐R1030, 2013.
 449.Platzack B, Conlon JM. Purification, structural characterization, and cardiovascular activity of cod bradykinins. Am J Physiol Regul Integr Comp Physiol 272: R710‐R717, 1997.
 450.Platzack B, Hicks JW. Reductions in systemic oxygen delivery induce a hypometabolic state in the turtle Trachemys scripta. Am J Physiol Regul Integr Comp Physiol 281: R1295‐R1301, 2001.
 451.Platzack B, Schaffert C, Hazon N, Conlon JM. Cardiovascular actions of dogfish urotensin I in the dogfish, Scyliorhinus canicula. Gen Comp Endocrinol 109: 269‐275, 1998.
 452.Platzack B, Wang Y, Crossley D, Lance V, Hicks JW, Conlon JM. Characterization and cardiovascular actions of endothelin‐1 and endothelin‐3 from the American alligator. Am J Physiol Regul Integr Comp Physiol 282: R594‐R602, 2002.
 453.Poder TC, Silberberg SD, Rampe D. Contraction of reptile, amphibian, and fish blood vessels by endothelin‐1. Can J Physiol Pharmacol 69: 215‐217, 1991.
 454.Ponganis P, Kooyman G, Sartoris D, Jobsis P. Pinniped splenic volumes. Am J Physiol Regul Integr Comp Physiol 262: R322‐R325, 1992.
 455.Ponganis P, Stockard T, Meir J, Williams C, Ponganis K, Howard R. O2 store management in diving Emperor penguins. J Exp Biol 212: 217‐224, 2009.
 456.Ponganis P, Stockard TK, Levenson D, Berg L, Baranov E. Intravascular pressure profiles in elephant seals: Hypotheses on the caval sphincter, extradural vein and venous return to the heart. Comp Biochem Physiol A Mol Integr Physiol 145: 123‐130, 2006.
 457.Ponganis PJ, Kooyman GL, Castellini MA. Determinants of the aerobic dive limit of weddell seals: Analysis of diving metabolic rates, postdive end tidal PO2's, and blood and muscle oxygen stores. Physiol Zool 732‐749, 1993.
 458.Ponganis PJ, Kooyman GL, Zornow MH. Cardiac output in swimming California sea lions, Zalophus californianus. Physiol Zool 1296‐1306, 1991.
 459.Ponganis PJ, Kooyman GL, Zornow MH, Castellini MA, Croll DA. Cardiac output and stroke volume in swimming harbor seals. J Comp Physiol [B] 160: 473‐482, 1990.
 460.Poole DC, Erickson HH. Highly athletic terrestrial mammals: Horses and dogs. Comprehensive Physiology, John Wiley & Sons, 2011.
 461.Portner HO. Climate variations and the physiological basis of temperature dependent biogeography: Systemic to molecular hierarchy of thermal tolerance in animals. Comp Biochem Physiol A Mol Integr Physiol l 132: 739‐761, 2002.
 462.Potts W. Excretion in the molluscs. Biologic Rev 42: 1‐41, 1967.
 463.Poupa O, Lindström L. Comparative and scaling aspects of heart and body weights with reference to blood supply of cardiac fibers. Comp Biochem Physiol A Physiol 76: 413‐421, 1983.
 464.Prange HD, Schmidt‐Nielsen K. The metabolic cost of swimming in ducks. J Exp Biol 53: 763‐777, 1970.
 465.Priede IG. The effect of swimming activity and section of the vagus nerves on heart rate in rainbow trout. J Exp Biol 60: 305‐319, 1974.
 466.Prusch RD. Osmotic and ionic relationships in the fresh‐water flatworm, Dugesia dorotocephala. Comp Biochem Physiol A Physiol 54: 287‐290, 1976.
 467.Qvist J, Hill RD, Schneider RC, Falke KJ, Liggins GC, Guppy M, Elliot RL, Hochachka PW, Zapol WM. Hemoglobin concentrations and blood gas tensions of free‐diving Weddell seals. J Appl Physiol 61: 1560‐1569, 1986.
 468.Olson KR. The cardiovascular system. In: Evans HD, editor. The Physiology of Fishes. Boca Raton: CRC Press, 1998, pp. 129‐154.
 469.Race GJ, Edwards WL, Halden ER, Wilson HE, Luibel FJ. A large whale heart. Circulation 19: 928‐932, 1959.
 470.Ramos C. The structure and ultrastructure of the sinus venosus in the mature dogfish (Scyliorhinus canicula): The endocardium, the epicardium and the subepicardial space. Tissue Cell 36: 399‐407, 2004.
 471.Randall D. The circulatory system. Fish Physiol 4: 133‐172, 1970.
 472.Randall D. The control of respiration and circulation in fish during exercise and hypoxia. J Exp Biol 100: 275‐288, 1982.
 473.RANDALL D, BRAUNER C. Effects of environmental factors on exercise in fish. J Exp Biol 160: 113‐126, 1991.
 474.Randall DJ, Burggren WW, Haswell MS, Farrell AP. The Evolution of Air Breathing in Vertebrates. Cambridge: Cambridge University Press, 1981.
 475.Rea MS, Parsons RH. Evidence of nitric oxide and angiotensin II regulation of circulation and cutaneous drinking in Bufo marinus. Physiol Biochem Zool 74: 127‐133, 2001.
 476.Reeves JT, Groves BM, Cymerman A, Sutton JR, Wagner PD, Turkevich D, Houston CS. Operation Everest II: Cardiac filling pressures during cycle exercise at sea level. Respir Physiol 80: 147‐154, 1990.
 477.Reiber C, McMahon B, Burggren W. Cardiovascular functions in two macruran decapod crustaceans (Procambarus clarkii and Homarus americanus) during periods of inactivity, tail flexion and cardiorespiratory pauses. J Exp Biol 200: 1103‐1113, 1997.
 478.Reiber CL. Hemodynamics of the crayfish Procambarus clarkii. Physiol Zool 449‐467, 1994.
 479.Reid IA. Angiotensin II and baroreflex control of heart rate. Physiology 11: 270‐274, 1996.
 480.Reiswig H. In situ pumping activities of tropical Demospongiae. Marine Biology 9: 38‐50, 1971.
 481.Reuter H. Calcium channel modulation by neurotransmitters, enzymes and drugs. Nature 301: 569‐574, 1983.
 482.Ridgway SH, Carder DA, Clark W. Conditioned bradycardia in the sea lion Zalophus californianus. Nature 256: 36‐37, 1975.
 483.Rieger RM. Morphology of the Turbellaria at the ultrastructural level. Hydrobiologia 84: 213‐229, 1981.
 484.Ringer S. A further contribution regarding the influence of the different constituents of the blood on the contraction of the heart. J Physiol 4: 29‐42, 1883.
 485.Robinson TF, Winegrad S. The measurement and dynamic implications of thin filament lengths in heart muscle. J Physiol 286: 607‐619, 1979.
 486.Rødland TP, Nilsson GE. Endothelin induced cerebral vasoconstriction in rainbow trout, detected in a novel in vitro preparation. Neurosci Lett 325: 195‐198, 2002.
 487.Rodnick KJ, Sidell BD. Structural and biochemical analyses of cardiac ventricular enlargement in cold‐acclimated striped bass. Am J Physiol Regul Integr Comp Physiol 273: R252‐R258, 1997.
 488.Rollema HS, Bauer C. The interaction of inositol pentaphosphate with the hemoglobins of highland and lowland geese. J Biol Chem 254: 12038‐12043, 1979.
 489.Rome LC, Loughna PT, Goldspink G. Temperature acclimation: Improved sustained swimming performance in carp at low temperatures. Science 228: 194‐196, 1985.
 490.Ronald K, McCarter R, Selley L. Venous circulation in the harp seal (Pagophilus groenlandicus). Functional Anatomy of Marine Mammals 3: 235‐270, 1977.
 491.Rowell LB, O'Leary DS, Kellogg DL. Integration of Cardiovascular Control Systems in Dynamic Exercise. Compr Physiol 2011, Supplement 29: Handbook of Physiology, Exercise: Regulation and Integration of Multiple Systems: 770-838. First published in print 1996. doi: 10.1002/cphy.cp120117.
 492.Rowland T, Garrison A, Delulio A. Circulatory responses to progressive exercise: Insights from positional differences. Int J Sports Med 24: 512‐517, 2003.
 493.Rowland TW. Circulatory responses to exercise: Are we misreading fick? CHEST 127: 1023‐1030, 2005.
 494.Ruben JA, Bennett AF. Intense exercise, bone structure and blood calcium levels in vertebrates. Nature 291: 411‐413, 1981.
 495.Rupert E, Barnes R. Invertebrate Zoology. Philadelphia: Saunders College Publication, Fort Worth, 1994.
 496.Rushmer RF. Organ Physiology: Structure and Function of the Cardiovascular System. Philadelphia: WB Sanders, 1976.
 497.Saetersdal TS, Sorensen E, Myklebust R, Helle KB. Granule containing cells and fibres in the sinus venosus of elasmobranchs. Cell Tissue Res 163: 471‐490, 1975.
 498.Sandblom E, Axelsson M. Autonomic control of circulation in fish: A comparative view. Auton Neurosci 165: 127‐139, 2011.
 499.Sandblom E, Axelsson M, Farrell AP. Central venous pressure and mean circulatory filling pressure in the dogfish Squalus acanthias: Adrenergic control and role of the pericardium. Am J Physiol Regul Integr Comp Physiol 291: R1465‐R1473, 2006.
 500.Sandrini LR, Avian M. Feeding mechanism of Pelagia noctiluca (Scyphozoa: Semaeostomeae); laboratory and open sea observations. Marine Biol 102: 49‐55, 1989.
 501.Santer RM. Morphology and innervation of the fish heart. Adv Anat Embryol Cell Biol 89: 1, 1985.
 502.Sarnoff SJ, Mitchell J. The control of the function of the heart. Handbook of Physiology, Vol. 1, Washington, DC: The American Physiological Society, 1962, p. 489.
 503.Sasaki T, Inui M, Kimura Y, Kuzuya T, Tada M. Molecular mechanism of regulation of Ca2+ pump ATPase by phospholamban in cardiac sarcoplasmic reticulum. Effects of synthetic phospholamban peptides on Ca2+ pump ATPase. J Biol Chem 267: 1674‐1679, 1992.
 504.Satchell GH. Physiology and Form of Fish Circulation. Cambridge, New York: Cambridge University Press, 1991.
 505.Sathar F, Ludo Badlangana N, Manger PR. Variations in the thickness and composition of the skin of the giraffe. Anat Rec 293: 1615‐1627, 2010.
 506.Schlant RC, Sonnenblick EH, Katz A. Normal physiology of the cardiovascular system. The Heart, 8th ed. New York: McGraw Hill, 1994, pp. 113‐151.
 507.Schumacher U, Welsch U. Histological, histochemical, and fine structural observations on the spleen of seals. American J Anat 179: 356‐368, 1987.
 508.Scott GR, Egginton S, Richards JG, Milsom WK. Evolution of muscle phenotype for extreme high altitude flight in the bar‐headed goose. Proc R Soc Lond B Biol Sci 276: 3645‐3653, 2009.
 509.Scott GR, Hawkes LA, Frappell PB, Butler PJ, Bishop CM, Milsom WK. How bar‐headed geese fly over the Himalayas. Physiology 30: 107‐115, 2015.
 510.Scott GR, Milsom WK. Control of breathing and adaptation to high altitude in the bar‐headed goose. Am J Physiol Regul Integr Comp Physiol 293: R379‐R391, 2007.
 511.Scott GR, Schulte PM, Egginton S, Scott AL, Richards JG, Milsom WK. Molecular evolution of cytochrome C oxidase underlies high‐altitude adaptation in the bar‐headed goose. Mol Biol Evol 28: 351‐363, 2011.
 512.Seth H, Sandblom E, Holmgren S, Axelsson M. Effects of gastric distension on the cardiovascular system in rainbow trout (Oncorhynchus mykiss). Am J Physiol Regul Integr Comp Physiol 294: R1648‐R1656, 2008.
 513.Seymour RS, Blaylock AJ. The principle of Laplace and scaling of ventricular wall stress and blood pressure in mammals and birds. Physiol Biochem Zool 73: 389‐405, 2000.
 514.Seymour RS, Hargens AR, Pedley TJ. The heart works against gravity. Am J Physiol Regul Integr Comp Physiol 265: R715‐R720, 1993.
 515.Seymour RS, Johansen K. Blood flow uphill and downhill: does a siphon facilitate circulation above the heart? Comp Biochem Physiol A Physiol 88: 167‐170, 1987.
 516.Shabetai R, Abel DC, Graham JB, Bhargava V, Keyes RS, Witztum K. Function of the pericardium and pericardioperitoneal canal in elasmobranch fishes. Am J Physiol Heart Circ Physiol 248: H198‐H207, 1985.
 517.Shahbazi F, Conlon JM, Holmgren S, Jensen J. Effects of cod bradykinin and its analogs on vascular and intestinal smooth muscle of the Atlantic cod, Gadus morhua. Peptides 22: 1023‐1029, 2001.
 518.Shattock MJ, Bers DM. Inotropic response to hypothermia and the temperature‐dependence of ryanodine action in isolated rabbit and rat ventricular muscle: Implications for excitation‐contraction coupling. Circ Res 61: 761‐771, 1987.
 519.Shelton G, Burggren W. Cardiovascular dynamics of the chelonia during apnoea and lung ventilation. J Exp Biol 64: 323‐343, 1976.
 520.Sheriff DD, Zhou XP, Scher AM, Rowell LB. Dependence of cardiac filling pressure on cardiac output during rest and dynamic exercise in dogs. Am J Physiol Heart Circ Physiol 265: H316‐H322, 1993.
 521.Shiels H, Farrell A. The effect of temperature and adrenaline on the relative importance of the sarcoplasmic reticulum in contributing Ca2+ to force development in isolated ventricular trabeculae from rainbow trout. J Exp Biol 200: 1607‐1621, 1997.
 522.Shiels H, Vornanen M, Farrell A. Temperature‐dependence of L‐type Ca2+ channel current in atrial myocytes from rainbow trout. J Exp Biol 203: 2771‐2780, 2000.
 523.Shiels HA, Stevens ED, Farrell AP. Effects of temperature, adrenaline and ryanodine on power production in rainbow trout oncorhynchus mykiss ventricular trabeculae. J Exp Biol 201(Pt 19): 2701‐2710, 1998.
 524.Shiels HA, Vornanen M, Farrell AP. Acute temperature change modulates the response of ICa to adrenergic stimulation in fish cardiomyocytes. Physiol Biochem Zool 76: 816‐824, 2003.
 525.Shiels HA, Vornanen M, Farrell AP. The force‐frequency relationship in fish hearts–a review. Comp Biochem Physiol A Mol Integr Physiol 132: 811‐826, 2002.
 526.Shiels HA, Vornanen M, Farrell AP. Temperature dependence of cardiac sarcoplasmic reticulum function in rainbow trout myocytes. J Exp Biol 205: 3631‐3639, 2002.
 527.Shiels HA, White E. Temporal and spatial properties of cellular Ca2+ flux in trout ventricular myocytes. Am J Physiol Regul Integr Comp Physiol 288: R1756‐R1766, 2005.
 528.Shiels HA, White E. The Frank–Starling mechanism in vertebrate cardiac myocytes. J Exp Biol 211: 2005‐2013, 2008.
 529.Shigei T, Tsuru H, Ishikawa N, Yoshioka K. Absence of endothelium in invertebrate blood vessels: Significance of endothelium and sympathetic nerve/medial smooth muscle in the vertebrate vascular system. Jpn J Pharmacol 87: 253‐260, 2001.
 530.Simonot D, Farrell A. Coronary vascular volume remodelling in rainbow trout Oncorhynchus mykiss. J Fish Biol 75: 1762‐1772, 2009.
 531.Simonot DL, Farrell AP. Cardiac remodelling in rainbow trout Oncorhynchus mykiss Walbaum in response to phenylhydrazine‐induced anaemia. J Exp Biol 210: 2574‐2584, 2007.
 532.Simpson JG, Gilmartin WG, Ridgway SH. Blood volume and other hematologic values in young elephant seals (Mirounga angustirostris). Am J Vet Res 31: 1449‐1452, 1970.
 533.Sisson JE, III, Sidell BD. Effect of thermal acclimation on muscle fiber recruitment of swimming striped bass (Morone saxatilis). Physiol Zool 310‐320, 1987.
 534.Sitsapesan R, Montgomery R, MacLeod K, Williams A. Sheep cardiac sarcoplasmic reticulum calcium‐release channels: Modification of conductance and gating by temperature. Journal of Physiology 434: 469‐488, 1991.
 535.Skovgaard N, Galli G, Abe A, Taylor EW, Wang T. The role of nitric oxide in regulation of the cardiovascular system in reptiles. Comp Biochem Physiol A Mol Integr Physiol 142: 205‐214, 2005.
 536.Skovgaard N, Warren DE, Jackson DC, Wang T. Endothelin‐1 causes systemic vasodilatation in anaesthetised turtles (Trachemys scripta) through activation of ETB‐receptors. J Exp Biol 208: 3739‐3746, 2005.
 537.Skovgaard N, Zibrandtsen H, Laursen BE, Simonsen U, Wang T. Hypoxia‐induced vasoconstriction in alligator (Alligator mississippiensis) intrapulmonary arteries: A role for endothelin‐1? J Exp Biol 211: 1565‐1570, 2008.
 538.Sleet R, Sumich J, Weber L. Estimates of total blood volume and total body weight of a sperm whale (Physeter catodon). Can J Zool 59: 567‐570, 1981.
 539.Small S, MacDonald C, Farrell A. Vascular reactivity of the coronary artery in rainbow trout (Oncorhynchus mykiss). Am J Physiol Regul Integr Comp Physiol 258: R1402‐R1410, 1990.
 540.Smerup M, Funder J, Sloth E, Buus S, Aalkjaer C, Wang T, Brondum E, Secher NH, Bie P, Damkjaer M. How can a normal‐sized heart generate high blood pressure in the Giraffe? FASEB J 25: 1045.1048, 2011.
 541.Smith D. Evidence for pulmonary vasoconstriction during hypercapnia in the toad Bufo marinus. Can J Zool 56: 1530‐1534, 1978.
 542.Smith DG, Nilsson S, Wahlqvist I, Eriksson B‐M. Nervous control of the blood pressure in the Atlantic cod, Gadus morhua. J Exp Biol 117: 335‐347, 1985.
 543.Smith P. Integrated cardiovascular control in the Mollusca. Physiol Zool 12‐34, 1990.
 544.Soderstrom V, Nilsson GE, Renshaw GM, Franklin CE. Hypoxia stimulates cerebral blood flow in the estuarine crocodile (Crocodylus porosus). Neurosci Lett 267: 1‐4, 1999.
 545.Soderstrom V, Renshaw G, Nilsson GE. Brain blood flow and blood pressure during hypoxia in the epaulette shark Hemiscyllium ocellatum, a hypoxia‐tolerant elasmobranch. J Exp Biol 202: 829‐835, 1999.
 546.Soderstrom‐Lauritzsen V, Nilsson GE, Lutz PL. Effect of anoxia and adenosine on cerebral blood flow in the leopard frog (Rana pipiens). Neurosci Lett 311: 85‐88, 2001.
 547.Sommer JR, Johnson EA. Ultrastructure of cardiac muscle. Handbook of Physiology, Vol. 2. Washington, DC: The American Physiological Society, 1979, pp. 113‐186.
 548.Sonnenblick EH, Downing SE. Afterload as a primary determinant of ventricular performance. Am J Physiol 204: 604‐610, 1963.
 549.Stahl WR. Scaling of respiratory variables in mammals. J Appl Physiol 22: 453‐460, 1967.
 550.Starling EH. The Linacre Lecture on the Law of the Heart. London and New York: Longmans‐Green, 1918.
 551.Stauss HM. Identification of blood pressure control mechanisms by power spectral analysis. Clin Exp Pharmacol Physiol 34: 362‐368, 2007.
 552.Stecyk JA, Overgaard J, Farrell AP, Wang T. Alpha‐adrenergic regulation of systemic peripheral resistance and blood flow distribution in the turtle Trachemys scripta during anoxic submergence at 5 degrees C and 21 degrees C. J Exp Biol 207: 269‐283, 2004.
 553.Stecyk JA, Skovgaard N, Nilsson GE, Wang T. Vasoactivity of hydrogen sulfide in normoxic and anoxic turtles (Trachemys scripta). Am J Physiol Regul Integr Comp Physiol 298: R1225‐R1239, 2010.
 554.Stecyk JA, Stensløkken K‐O, Nilsson GE, Farrell AP. Adenosine does not save the heart of anoxia‐tolerant vertebrates during prolonged oxygen deprivation. Comp Biochem Physiol A Mol Integr Physiol 147: 961‐973, 2007.
 555.Stecyk JAW, Farrell AP. Regulation of the cardiorespiratory system of common carp (Cyprinus carpio) during severe hypoxia at three seasonal acclimation temperatures. Physiol Biochem Zool 79: 614‐627, 2006.
 556.Steffensen JF, Farrell A. Swimming performance, venous oxygen tension and cardiac performance of coronary‐ligated rainbow trout, Oncorhynchus mykiss, exposed to progressive hypoxia. Comp Biochem Physiol A Mol Integr Physiol 119: 585‐592, 1998.
 557.Stensløkken K‐O, Sundin L, Nilsson GE. Endothelin receptors in teleost fishes: Cardiovascular effects and branchial distribution. Am J Physiol Regul Integr Comp Physiol 290: R852‐R860, 2006.
 558.Stensløkken K‐O, Sundin L, Renshaw GM, Nilsson GE. Adenosinergic and cholinergic control mechanisms during hypoxia in the epaulette shark (Hemiscyllium ocellatum), with emphasis on branchial circulation. J Exp Biol 207: 4451‐4461, 2004.
 559.Stevens ED. The effect of exercise on the distribution of blood to various organs in rainbow trout. Comp Biochem Physiol 25: 615‐625, 1968.
 560.Stevens ED, Bennion G, Randall D, Shelton G. Factors affecting arterial pressures and blood flow from the heart in intact, unrestrained lingcod, Ophiodon elongatus. Comp Biochem Physiol A Physiol 43: 681‐695, 1972.
 561.Stewart AG. Swans flying at 8,000 metres. Brit Birds 71: 459‐560, 1978.
 562.Storz JF, Scott GR, Cheviron ZA. Phenotypic plasticity and genetic adaptation to high‐altitude hypoxia in vertebrates. J Exp Biol 213: 4125‐4136, 2010.
 563.Stray‐Gundersen J, Musch TI, Haidet GC, Swain DP, Ordway GA, Mitchell JH. The effect of pericardiectomy on maximal oxygen consumption and maximal cardiac output in untrained dogs. Circ Res 58: 523‐530, 1986.
 564.Strobeck JE, Bahler AS, Sonnenblick EH. Isotonic relaxation in cardiac muscle. Am J Physiol 229: 646‐651, 1975.
 565.Sundin L, Axelsson M, Davison W, Forster ME. Cardiovascular responses to adenosine in the Antarctic fish Pagothenia borchgrevinki. J Exp Biol 202: 2259‐2267, 1999.
 566.Sundin L, Nilsson GE. Branchial and systemic roles of adenosine receptors in rainbow trout: An in vivo microscopy study. Am J Physiol Regul Integr Comp Physiol 271: R661‐R669, 1996.
 567.Svärd C, Fahlman A, Rosen D, Joy R, Trites A. Fasting affects the surface and diving metabolic rates of Steller sea lions Eumetopias jubatus. Aquatic Biol 8: 71‐82, 2009.
 568.Swan L. Goose of the Himalayas. Nat History 79: 68‐75, 1970.
 569.Sweitzer NK, Moss RL. The effect of altered temperature on Ca2+‐sensitive force in permeabilized myocardium and skeletal muscle. Evidence for force dependence of thin filament activation. J Gen Physiol 96: 1221‐1245, 1990.
 570.Swenson KE, Eveland RL, Gladwin MT, Swenson ER. Nitric oxide (NO) in normal and hypoxic vascular regulation of the spiny dogfish, Squalus acanthias. J Exp Zool A: Compar Exp Biol 303: 154‐160, 2005.
 571.Syme DA, Gamperl K, Jones DR. Delayed depolarization of the cog‐wheel valve and pulmonary‐to‐systemic shunting in alligators. J Exp Biol 205: 1843‐1851, 2002.
 572.Tabrizchi R, Bedi S. Pharmacology of adenosine receptors in the vasculature. Pharmacol Ther 91: 133‐147, 2001.
 573.Tada M, Kadoma M, Inui M, Fujii J. Regulation of Ca2+‐pump from cardiac sarcoplasmic reticulum. Methods Enzymol 157: 107‐154, 1988.
 574.Tada M, Toyofuku T. Cardiac sarcoplasmic Ca2+‐ATPase. In: Page E, Fozzard HA, Solaro RJ, editors. Handbook of Physiology, Section 2 The Cardiovascular System. New York: Oxford University Press, 2002, pp. 301‐334.
 575.Taegtmeyer H. Energy metabolism of the heart: From basic concepts to clinical applications. Curr Probl Cardiol 19: 61‐113, 1994.
 576.Tagawa T, Andō K, Wasano T, Iijima T. A histochemical study on the innervation of cerebral blood vessels in the bullfrog. J Comp Neurol 183: 25‐32, 1979.
 577.Taylor CR, Weibel ER. Design of the mammalian respiratory system. I. Problem and strategy. Respir Physiol 44: 1‐10, 1981.
 578.Taylor E. Control and co‐ordination of ventilation and circulation in crustaceans: Responses to hypoxia and exercise. J Exp Biol 100: 289‐319, 1982.
 579.Taylor E, Andrade DV, Abe AS, Leite CA, Wang T. The unequal influences of the left and right vagi on the control of the heart and pulmonary artery in the rattlesnake, Crotalus durissus. J Exp Biol 212: 145‐151, 2009.
 580.Taylor E, Butler P, Al‐Wassia A. Some responses of the shore crab, Carcinus maenas (L.) to progressive hypoxia at different acclimation temperatures and salinities. J Comp Physiol 122: 391‐402, 1977.
 581.Taylor E, Leite C, Skovgaard N. Autonomic control of cardiorespiratory interactions in fish, amphibians and reptiles. Braz J Med Biol Res 43: 600‐610, 2010.
 582.Taylor E, Wang T. Control of the heart and of cardiorespiratory interactions in ectothermic vertebrates. In: Cardio‐Respiratory Control in Vertebrates. Springer: Springer-Verlag Berlin Heidelberg, 2009, pp. 285‐315.
 583.Taylor EW, Jordan D, Coote JH. Central control of the cardiovascular and respiratory systems and their interactions in vertebrates. Physiol Rev 79: 855‐916, 1999.
 584.Taylor S, Egginton S, Taylor E. Seasonal temperature acclimatisation of rainbow trout: Cardiovascular and morphometric influences on maximal sustainable exercise level. J Exp Biol 199: 835‐845, 1996.
 585.Tempel D, Westheide W. Uptake and incorporation of dissolved amino acids by interstitial Turbellaria and Polychaeta and their dependence on temperature and salinity. Marine Ecol Prog Ser 3: 41‐50, 1980.
 586.Territo P, Altimiras J. Morphometry and estimated bulk oxygen diffusion in larvae of Xenopus laevis under chronic carbon monoxide exposure. J Comp Physiol [B] 171: 145‐153, 2001.
 587.Territo PR, Altimiras J. The ontogeny of cardio‐respiratory function under chronically altered gas compositions in Xenopus laevis. Respir Physiol 111: 311‐323, 1998.
 588.Territo PR, Burggren WW. Cardio‐respiratory ontogeny during chronic carbon monoxide exposure in the clawed frog Xenopus laevis. J Exp Biol 201: 1461‐1472, 1998.
 589.Thomas DP, Fregin GF. Cardiorespiratory and metabolic responses to treadmill exercise in the horse. J Appl Physiol 50: 864‐868, 1981.
 590.Thomas MJ, Hamman BN, Tibbits GF. Dihydropyridine and ryanodine binding in ventricles from rat, trout, dogfish and hagfish. J Exp Biol 199: 1999‐2009, 1996.
 591.Thorarensen H, Gallaugher P, Kiessling A, Farrell A. Intestinal blood flow in swimming chinook salmon Oncorhynchus tshawytscha and the effects of haematocrit on blood flow distribution. J Exp Biol 179: 115‐129, 1993.
 592.Thornton SJ, Spielman DM, Pelc NJ, Block WF, Crocker DE, Costa DP, LeBoeuf BJ, Hochachka PW. Effects of forced diving on the spleen and hepatic sinus in northern elephant seal pups. Proc Natl Acad Sci U S A 98: 9413‐9418, 2001.
 593.Tibbits GF, Hove‐Madsen L, Bers DM. Calcium transport and the regulation of cardiac contractility in teleosts: A comparison with higher vertebrates. Can J Zool 69: 2014‐2019, 1991.
 594.Tibbits GF, Kashihara H, Thomas MJ, Keen JE, Farrell AP. Ca2+ transport in myocardial sarcolemma from rainbow trout. Am J Physiol Regul Integr Comp Physiol 259: R453‐R460, 1990.
 595.Tiitu V, Vornanen M. Ryanodine and dihydropyridine receptor binding in ventricular cardiac muscle of fish with different temperature preferences. J Comp Physiol [B] 173: 285‐291, 2003.
 596.Toda N, Ayajiki K. Phylogenesis of constitutively formed nitric oxide in non‐mammals. Rev Physiol Biochem Pharmacol 157: 31‐80, 2006.
 597.Tomanek R, Ratajska A. Vasculogenesis and angiogenesis in the developing heart. In: Burggren W, Keller B, editors. Development of Cardiovascular Systems: Molecules to Organisms Cambridge University Press, Cambridge. New York: Cambridge University Press, 1997, pp. 35‐42.
 598.Tota B. Vascular and metabolic zonation in the ventricular myocardium of mammals and fishes. Comp Biochem Physiol A Mol Integr Physiol 76: 423‐437, 1983.
 599.Tota B, Gattuso A. Heart ventricle pumps in teleosts and elasmobranchs: A morphodynamic approach. J Exp Zool 275: 162‐171, 1996.
 600.Toulmond A. Adaptations to extreme environmental hypoxia in water breathers. In: Dejour P, editor. Comparative Physiology of Environmental Adaptations. Strasbourg: Basel: Karger, 1986.
 601.Trautwein W, Hescheler J. Regulation of cardiac L‐type calcium current by phosphorylation and G proteins. Annu Rev Physiol 52: 257‐274, 1990.
 602.Tsakiris AG, Donald DE, Sturm RE, Wood EH. Volume, ejection fraction, and internal dimensions of left ventricle determined by biplane videometry. Fed Proc 28: 1358‐1367, 1969.
 603.Tufts BL, Mense DC, Randall DJ. The effects of forced activity on circulating catecholamines and pH and water content of erythrocytes in the toad. J Exp Biol 128: 411‐418, 1987.
 604.Turbeville J, Ruppert E. Comparative ultrastructure and the evolution of nemertines. Amer Zool 25: 53‐71, 1985.
 605.Turbeville JM. Nemertinea. In: Harrison FW, Humes AG, editors. Microscopic Anatomy of Invertebrates. New York: Wiley‐Liss, 1991.
 606.Vagvolgyi J. On the origin of molluscs, the coelom, and coelomic segmentation. Syst Biol 16: 153‐168, 1967.
 607.Van Citters RL, Franklin DL, Vatner SF, Patrick T, Warren JV. Cerebral hemodynamics in the giraffe. Trans Assoc Am Physicians 82: 293‐304, 1969.
 608.Van Citters RL, Kemper WS, Franklin DL. Blood pressure responses of wild giraffes studied by radio telemetry. Science 152: 384‐386, 1966.
 609.Van Citters RL, Kemper WS, Franklin DL. Blood flow and pressure in the giraffe carotid artery. Comp Biochem Physiol 24: 1035‐1042, 1968.
 610.Van Lieshout JJ, Wieling W, Karemaker JM, Secher NH. Syncope, cerebral perfusion, and oxygenation. J Appl Physiol 94: 833‐848, 2003.
 611.Vogel S. Current‐induced flow through the sponge, Halichondria. Biol Bull 147: 443‐456, 1974.
 612.Vornanen M. Regulation of contractility of the fish (Carassius carassius L.) heart ventricle. Comp Biochem Physiol C 94: 477‐483, 1989.
 613.Vornanen M. L‐type Ca2+ current in fish cardiac myocytes: Effects of thermal acclimation and beta‐adrenergic stimulation. J Exp Biol 201: 533‐547, 1998.
 614.Vornanen M, Shiels HA, Farrell AP. Plasticity of excitation‐contraction coupling in fish cardiac myocytes. Comp Biochem Physiol A Mol Integr Physiol 132: 827‐846, 2002.
 615.Vornanen M, Tuomennoro J. Effects of acute anoxia on heart function in crucian carp: Importance of cholinergic and purinergic control. Am J Physiol Regul Integr Comp Physiol 277: R465‐R475, 1999.
 616.Wagner PD. Reduced maximal cardiac output at altitude—mechanisms and significance. Respir Physiol 120: 1‐11, 2000.
 617.Wang R. Two's company, three'sa crowd: Can H2S be the third endogenous gaseous transmitter? FASEB J 16: 1792‐1798, 2002.
 618.Wang T, Axelsson M, Jensen J, Conlon JM. Cardiovascular actions of python bradykinin and substance P in the anesthetized python, Python regius. Am J Physiol Regul Integr Comp Physiol 279: R531‐R538, 2000.
 619.Wang T, Hedrick MS, Ihmied YM, Taylor EW. Control and interaction of the cardiovascular and respiratory systems in anuran amphibians. Comp Biochem Physiol A Mol Integr Physiol 124: 393‐406, 1999.
 620.Wang YX, Zhou T, Chua TC, Pang CC. Effects of inhalation and intravenous anesthetic agents on pressor response to NG‐nitro‐L‐arginine. Eur J Pharmacol 198: 183‐188, 1991.
 621.Ward S, Bishop CM, Woakes AJ, Butler PJ. Heart rate and the rate of oxygen consumption of flying and walking barnacle geese (Branta leucopsis) and bar‐headed geese (Anser indicus). J Exp Biol 205: 3347‐3356, 2002.
 622.Burggren WW. What is the purpose of the embryonic heart beat? Or how facts can ultimately prevail over physiological dogma. Physiol Biochem Zool 77: 333‐345, 2004.
 623.Wasser JS, Meinertz EA, Chang SY, Lawler RG, Jackson DC. Metabolic and cardiodynamic responses of isolated turtle hearts to ischemia and reperfusion. Am J Physiol Regul Integr Comp Physiol 262: R437‐R443, 1992.
 624.Weber RE, Jessen T‐H, Malte H, Tame J. Mutant hemoglobins (alpha 119‐Ala and beta 55‐Ser): Functions related to high‐altitude respiration in geese. J Appl Physiol 75: 2646‐2655, 1993.
 625.West JB, American College of P, American Physiological S. The physiologic basis of high‐altitude diseases. Ann Intern Med 141: 789‐800, 2004.
 626.West JB, Mathieu‐Costello O, Jones JH, Birks EK, Logemann RB, Pascoe JR, Tyler WS. Stress failure of pulmonary capillaries in racehorses with exercise‐induced pulmonary hemorrhage. J Appl Physiol 75: 1097‐1109, 1993.
 627.West NH, Burggren WW. Factors influencing pulmonary and cutaneous arterial blood flow in the toad, Bufo marinus. Am J Physiol Regul Integr Comp Physiol 247: R884‐R894, 1984.
 628.West NH, Smits AW. Cardiac output in conscious toads (Bufo marinus). J Exp Biol 186: 315‐323, 1994.
 629.White FN, Ikeda M, Elsner RW. Adrenergic innervation of large arteries in the seal. Comp Gen Pharmacol 4: 271‐276, 1973.
 630.Wier WG, Balke CW. Ca2+ release mechanisms, Ca2+ sparks, and local control of excitation‐contraction coupling in normal heart muscle. Circ Res 85: 770‐776, 1999.
 631.Wiersma C, Novitski E. The mechanism of the nervous regulation of the crayfish heart. J Exp Biol 19: 255‐265, 1942.
 632.Wilkens J, Davidson G, Cavey M. Vascular peripheral resistance and compliance in the lobster Homarus americanus. J Exp Biol 200: 477‐485, 1997.
 633.Wilkens J, Wilkens L, McMahon B. Central control of cardiac and scaphognathite pacemakers in the crab, Cancer magister. J Comp Physiol 90: 89‐104, 1974.
 634.Wilkens JL. Evolution of the cardiovascular system in Crustacea. Amer Zool 39: 199‐214, 1999.
 635.Wilkens JL, Cavey MJ, Shovkivska I, Zhang ML, ter Keurs HE. Elasticity, unexpected contractility and the identification of actin and myosin in lobster arteries. J Exp Biol 211: 766‐772, 2008.
 636.Wilkens JL, Taylor HH. The control of vascular resistance in the southern rock lobster, Jasus edwardsii (Decapoda: Palinuridae). Comp Biochem Physiol A Mol Integr Physiol 135: 369‐376, 2003.
 637.Willenz P, Hartman W. Micromorphology and ultrastructure of Caribbean sclerosponges. Marine Biol 103: 387‐401, 1989.
 638.Withers PC, Hedrick MS, Drewes RC, Hillman SS. Pulmonary compliance and lung volume are related to terrestriality in anuran amphibians. Physiol Biochem Zool 87: 374‐383, 2014.
 639.Withers PC, Hillman SS, Simmons LA, Zygmunt AC. Cardiovascular adjustments to enforced activity in the anuran amphibian, Bufo marinus. Comp Biochem Physiol A Physiol 89: 45‐49, 1988.
 640.Wolfenson D, Frei YF, Berman A. Blood flow distribution during artificially induced respiratory hypocapnic alkalosis in the fowl. Respir Physiol 50: 87‐92, 1982.
 641.Wu Y, Cazorla O, Labeit D, Labeit S, Granzier H. Changes in titin and collagen underlie diastolic stiffness diversity of cardiac muscle. J Mol Cell Cardiol 32: 2151‐2162, 2000.
 642.Yamamoto K‐i, Itazawa Y, Kobayashi H. Direct observation of fish spleen by an abdominal window method and its application to exercised and hypoxic yellowtail. Jpn J Ichthyol 31: 427‐433, 1985.
 643.Yoshinaga N, Okuno T, Watanabe Y, Matsumoto T, Shiraishi M, Obi T, Yabuki A, Miyamoto A. Vasomotor effects of noradrenaline, acetylcholine, histamine, 5‐hydroxytryptamine and bradykinin on snake (Trimeresurus flavoviridis) basilar arteries. Comp Biochem Physiol C Pharmacol Toxicol Endocrinol 146: 478‐483, 2007.
 644.Yue DT, Marban E, Wier W. Relationship between force and intracellular [Ca2+] in tetanized mammalian heart muscle. J Gen Physiol 87: 223‐242, 1986.
 645.Zhao W, Wang R. H(2)S‐induced vasorelaxation and underlying cellular and molecular mechanisms. Am J Physiol Heart Circ Physiol 283: H474‐H480, 2002.
 646.Zhao W, Zhang J, Lu Y, Wang R. The vasorelaxant effect of H2S as a novel endogenous gaseous KATP channel opener. EMBO J 20: 6008‐6016, 2001.

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Article Title: Mass Transport: Circulatory System with Emphasis on Nonendothermic Species
 

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Dane A. Crossley, Warren W. Burggren, Carl L. Reiber, Jordi Altimiras, Kenneth J. Rodnick. Mass Transport: Circulatory System with Emphasis on Nonendothermic Species. Compr Physiol 2016, 7: 17-66. doi: 10.1002/cphy.c150010