What is double circulation? Why is it necessary .
Tell four function of blood ?
In human beings, blood goes through the heart twice during each cycle i.e. blood passes through the human heart two times in order to supply blood once to the whole body. So, it is called double circulation.
The double circulation of blood includes:
(i) Systemic Circulation
(ii) Pulmonary Circulation
It is necessary for human being to separate oxygenated and deoxygenated blood because this makes their circulatory system more efficient and helps in maintaining the constant body temperature.
Function of blood
1.Blood carries oxygen from your lungs and to all your body cells
and carbon dioxide from your body cells
2.Blood carries waste products from your cellsto your kidneys to be removed
3.Blood transports nutrients and
other substances to your body cells
4.Cells and molecules in blood
fight infection and help heal wounds