Cardiovascular Dynamics in Fishes, Amphibians, and Reptiles*

Johansen, Kjell

doi:10.1111/j.1749-6632.1965.tb49417.x

Cited by 57 publications

(9 citation statements)

References 24 publications

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“…The atrium, or atria, of ectothermic vertebrates is very voluminous compared to those of endotherms and contributes more to ventricular filling than in endotherms [10], [72]. Surprisingly, the atrium/atria of all vertebrates constitutes close to 20% of the ventricular mass despite the difference in importance for ventricular filling.…”

Section: Discussionmentioning

confidence: 99%

“…The earliest ventricular trabeculations in reptiles are aggregated into parallel sheets and a similar design can be seen in embryonic hearts of all vertebrates and in formed hearts of most fish and amphibians and reptiles [17], [22], [53], [70], [72], [85]–[88]. The vertical septum of the formed non-crocodilian ventricle is among these sheets and because it is positioned immediately caudal to the atrioventricular valves, it has repeatedly been hypothesized to constitute an important part of the complete ventricular septum of mammals and birds (cf.…”

Section: Discussionmentioning

confidence: 99%

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Development of the Hearts of Lizards and Snakes and Perspectives to Cardiac Evolution

et al. 2013

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Birds and mammals both developed high performance hearts from a heart that must have been reptile-like and the hearts of extant reptiles have an unmatched variability in design. Yet, studies on cardiac development in reptiles are largely old and further studies are much needed as reptiles are starting to become used in molecular studies. We studied the growth of cardiac compartments and changes in morphology principally in the model organism corn snake (Pantherophis guttatus), but also in the genotyped anole (Anolis carolinenis and A. sagrei) and the Philippine sailfin lizard (Hydrosaurus pustulatus). Structures and chambers of the formed heart were traced back in development and annotated in interactive 3D pdfs. In the corn snake, we found that the ventricle and atria grow exponentially, whereas the myocardial volumes of the atrioventricular canal and the muscular outflow tract are stable. Ventricular development occurs, as in other amniotes, by an early growth at the outer curvature and later, and in parallel, by incorporation of the muscular outflow tract. With the exception of the late completion of the atrial septum, the adult design of the squamate heart is essentially reached halfway through development. This design strongly resembles the developing hearts of human, mouse and chicken around the time of initial ventricular septation. Subsequent to this stage, and in contrast to the squamates, hearts of endothermic vertebrates completely septate their ventricles, develop an insulating atrioventricular plane, shift and expand their atrioventricular canal toward the right and incorporate the systemic and pulmonary venous myocardium into the atria.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Development of the Hearts of Lizards and Snakes and Perspectives to Cardiac Evolution

et al. 2013

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“…This indicates, as previously suggested (Van Mierop & Kutsche, 1985 b ), that the vertical septum is not a true septum. Indeed, multiple trabecular sheets can be found in the ventricles of some sharks, where the pulmonary circulation is absent and only systemic venous blood returns to these hearts (Benninghoff, ; Johansen, ; Sanchez‐Quintana & Hurle, ).…”

Section: Reptile Heartsmentioning

confidence: 99%

Structure and function of the hearts of lizards and snakes

2013

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With approximately 7000 species, snakes and lizards, collectively known as squamates, are by far the most species-rich group of reptiles. It was from reptile-like ancestors that mammals and birds evolved and squamates can be viewed as phylogenetically positioned between them and fishes. Hence, their hearts have been studied for more than a century yielding insights into the group itself and into the independent evolution of the fully divided four-chambered hearts of mammals and birds. Structurally the heart is complex and debates persist on rudimentary issues such as identifying structures critical to understanding ventricle function. In seeking to resolve these controversies we have generated three-dimensional (3D) models in portable digital format (pdf) of the anaconda and anole lizard hearts ('typical' squamate hearts) and the uniquely specialized python heart with comprehensive annotations of structures and cavities. We review the anatomy and physiology of squamate hearts in general and emphasize the unique features of pythonid and varanid lizard hearts that endow them with mammal-like blood pressures. Excluding pythons and varanid lizards it is concluded that the squamate heart has a highly consistent design including a disproportionately large right side (systemic venous) probably due to prevailing pulmonary bypass (intraventricular shunting). Unfortunately, investigations on rudimentary features are sparse. We therefore point out gaps in our knowledge, such as the size and functional importance of the coronary vasculature and of the first cardiac chamber, the sinus venosus, and highlight areas with implications for vertebrate cardiac evolution.

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“…Chelonia mydas has thicker trabeculae in the left ventricular wall compared to those found on the right side wall. According to Johansen (), the spongy portion contributes to the development of fast and efficient ejection. In addition, the trabeculae of the spongy myocardium found in fish are morphologically adapted to capture blood through an intertrabecular vasculature network (Tota, ).…”

Section: Discussionmentioning

confidence: 99%

Histology and Immunohistochemistry of the Cardiac Ventricular Structure in the Green Turtle(Chelonia mydas)

Braz

Freitas

Magalhães

et al. 2015

Anat. Histol. Embryol.

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This study describes the implications of cardiac ventricular microscopy in Chelonia mydas relating to its ability to dive. For this work, 11 specimens of the marine turtle species C. mydas found dead on the coast of Rio Grande do Norte (Northeast Brazil) were used. After necropsy, fragments of the cardiac ventricular wall were fixed in 10% buffered formaldehyde solution for 24 h and then subjected to routine processing for light and scanning electron microscopy (SEM). The ventricle in this species is formed by the epicardium, myocardium and endocardium. The subepicardial layer consists of highly vascularised connective tissue that emits septa to reinforce the myocardium surface. There is an abundant and diffuse subepicardial nerve plexus shown by immunostaining technique. The thickness of the spongy myocardium and the nature of its trabeculae varied between the heart chambers. The endocardium shows no characteristic elements of the heart conduction system. The valves have a hyaline cartilage skeleton, coated by dense irregular connective tissues characterised by elastic fibres. These findings in the green turtle ventricular microscopy are related to hypoxia resistance during diving.

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Cardiovascular Dynamics in Fishes, Amphibians, and Reptiles*

Abstract: A 0 2 5 ' 1 40 Atropine + B F1GI:RE 2. Intrapericardial and ventral aortic pressure during administration of acetylcholine qnd atropine in 5' ocanthias (from Johansen, 1 9 6 4~) .

Cited by 57 publications

References 24 publications

Development of the Hearts of Lizards and Snakes and Perspectives to Cardiac Evolution

Development of the Hearts of Lizards and Snakes and Perspectives to Cardiac Evolution

Structure and function of the hearts of lizards and snakes

Histology and Immunohistochemistry of the Cardiac Ventricular Structure in the Green Turtle(Chelonia mydas)

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