Question

11. Compare the circulatory plans for a fish, amphibian and a reptilian. What is the significance of the Foramen Panizzae and the Foramen Ovale?

Answer 1

In the circulatorysystem of fish,fish have a closed loop circulatory system.Fish has the simplest circulatory system of the vertebrates.It consists of four chambers.It has only one atrium and one ventricle.The low oxygen blood that returns from the body enters the atrium and then the ventricle and is pumped out to the gills where the blood is oxygenated.

Amphibians has two circulatory systems.One system is for the oxygenation of the blood through lungs and skin and the other circulatory system take oxygen to the rest of the body.The amphibian heart is a tripartile structure,ie ,a divided atrium and a ventricle.

Reptiles circulatory system consists of heart,blood vessels,veins and arteries.It has two circulatory routes.Blood is oxygenated through the lungs .In reptiles the ventricles are partially seperated therefore mixture of oxygenated and unoxygenated blood occurs.

Foramen panizza is ahole connects the left and right aorta.It is seen in the order crocodilia.In this the oxygenated blood from the right ventricle can flow in to the right aorta through the foramen of panizza.And when the heart is at relaxed state ,oxygenated blood from the left ventricle flow in to the aorta across foramen of panizza.Fopramen ovale is ahole located in the septum.Right after the birth ,the fetus anatomic adaptation allow oxygenated blood coming from the umbilical vein through the inferior venacava to bypass pulmonary circulation.