Question
Sat August 11, 2012 By:

1. What is the difference between single and double circulation.

Expert Reply
Mon August 13, 2012

 

 

 

Single circulation

Double circulation

Here the blood flows only once through the heart during one cycle of passage through the body.

Here the blood flows twice through the heart during one cycle of passage through the body. 

It occurs in fishes.

It occurs in all other vertebrates other than fishes.

Only venous blood passes through the heart

Mixed or oxygenated or venous blood passes through heart.

This is less efficient as gill capillaries slow down the blood flow, hence the body receives blood at a low pressure which decreases the rate of oxygen supply to the cells.

This circulation is more efficient as blood flows at higher pressure (especially in birds and mammals). This increases the rate of supply of food and oxygen to the cell and also rapid removal of wastes from them.

 

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