Question

compare and contrast heart anatomy of

a) most reptiles (turtles, snakes, lizards)

b) crocodiles

c) birds

d) mammals

in terms of # of atria, # of ventricles, total # of chambers, and development of the aorta from aortic arches (left, right, or both).

Use a table

Include a drawing showing the basic template of dorsal aorta, ventral aorta, and six aortic arches, along with drawings showing the modified patterns of aortic arches in a-d above.

Answer 1

Reptile
reptiles have three chambered hearts with two atria and one common ventricle
The right atrium receives blood returning from the systemic circulation via the sinus venosus(which is formed by the confluence of the right and left precaval veins and the single postcaval vein.
left atrium receives oxygenated blood from the lungs via the pulmonary vein
The atrioventricular valves are bicuspid, membranous structures
the three chambered heart functions much like a four chambered structure, therefore relatively little mixing of oxygenated and de-oxygenated blood occurs.
ventricle and can be functionally separate; the cavum venosum, cavum arteriosum and the cavum pulmonale.
cavities are partially separated by two muscular ridges
cavum pulmonale receives blood from the right atrium through the cavum venosum and directs flow into the pulmonary circulation. The cavum arteriosum receives blood from the pulmonary veins and then directs oxygenated blood to the cavum venosu
. The paired aortic arches arise from the cavum venosum and lead to the systemic circulation.
The right and left aortic arches come together to form a single aorta at variable distances caudal to the heart

Crocodile
Crocodilians are the only reptiles which possess four chambered hearts comparable to mammals
Crocodilians possess two aortas; the right arising from the left ventricle and the left from the right ventricle. Both aortas route blood to the systemic circulation
The right and left aortas are connected near the base of the heart by the foramen of Panizza. The foramen allows blood from the right ventricle to bypass the pulmonary circulation

Birds
a 4-chambered heart (2 atria & 2 ventricles), with complete separation of oxygenated and de-oxygenated blood.
The right ventricle pumps blood to the lungs, while the left ventricle pumps blood to the rest of the body. Because the left ventricle must generate greater pressure to pump blood throughout the body (in contrast to the right ventricle that pumps blood to the lungs
Birds tend to have larger hearts than mammals (relative to body size and mass). The relatively large hearts of birds may be necessary to meet the high metabolic demands of flight
The right atrium tends to be larger than the left in most birds.
The atrioventricular (AV) valves of the heart of birds are similar in their anatomy to those of mammals however, the cusps of the valves are poorly defined.
The AV valve of the left side is tricuspid
Perfusion of the heart muscle is more active than in skeletal muscle

Mammal
The heart is divided into four chambers consisting of two atria and two ventricles; the atria receive blood, while the ventricles pump blood.
The right atrium receives blood from the superior and inferior vena cavas and the coronary sinus; blood then moves to the right ventricle where it is pumped to the lungs.
The atria are separated from the ventricles by Atrioventricular Valves (specifically called Tricuspid Valves - right; and Bicuspid/Mitral Valves - left).
In fetal heartforamen known as the foramen ovale seen. The foramen ovale allowed blood in the fetal heart to pass directly from the right atrium to the left atrium, allowing some blood to bypass the lungs