Heart evolution

What is the anatomy of the dogfish shark heart?

two chambers (1 atria and 1 ventricle)

What is the anatomy of the lungfish heart?

two chambers (1 atria and 1 ventricle)

What is the anatomy of the amphibian heart?

three chambered heart (2 atria and 1 ventricle)

What is the anatomy of the bird heart?

full four chambered heart (2 atria, 2 ventricles)

What is the anatomy of the mammal heart?

full four chambered heart (2 atria, 2 ventricles)

Do oxygenated and deoxygenated blood mix in the bird and mammal heart?

no

What is the circulatory pattern in fish?

single circulation

What is the pattern of blood flow in fish?

heart, gills, body, heart

What is the circulatory pattern in amphibians?

double circulation but incomplete separation of deoxygenated blood and oxygenated blood

What is the blood flow in amphibians?

Right atrium receives deoxygenated blood from the body, left atrium receives oxygenated blood from the lungs and skin, Both go into a single ventricle (some mixing occurs)

What is unique about the reptiles heart?

some have a complete septum which allows for better separation of oxygenated and deoxygenated blood

What is the circulatory pattern in birds and mammals?

double circulation

What is the flow of blood in the bird and mammal heart

Pulmonary circuit: Heart → lungs → heart

Systemic circuit: Heart → body → heart