All vertebrate possess a muscular heart. They show 3 types of Circulatory Pathways : Single circulation, Incomplete double circulation and Double circulation.
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| frogs'heart |
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| fish's heart |
- Single Circulation: Fishes show the single circulation pathway. Their hearts are 2-chambered with an atrium and a ventricle. The heart pumps out only deoxygenated blood to the gills for oxygenation. The oxygenated blood is supplied to all body parts and the deoxygenated blood from all the parts is returned to the heart.
- Incomplete Double Circulation: Amphibians and the Reptiles excluding crocodiles show the incomplete double circulation. The is 3 chambered with 2 atria and a ventricle. The left atrium receives oxygenated blood while the right atrium receives deoxygenated blood. But in single ventricle the oxygenated blood and deoxygenated blood get mixed up and that is pumped to all parts of the body. 3. Double Circulation: Aves and Mammals show the double circulation. The heart is 4 chambered with 2 atria and 2 ventricles. The oxygenated and deoxygenated blood are completely partitioned from each other. The left auricle receives oxygenated blood, that passes into the left ventricle which pumps it to all parts of the body. The right atrium receives deoxygenated blood from all the parts of the body that passes into the right ventricle which pumps it to the lungs for oxygenation.
I have a doubt
ReplyDeleteHow does the oxygen rich blood and oxygen poor blood manage to go separate ways after getting mixed up in a single ventricle