Question

Explain Double circulation. why is it an important event in human beings ?






( 5 marks )

Answer 1

During a single cycle blood goes twice in the heart which is known as double circulation. It is necessary in human being to separate oxygenated and de-oxygenated blood because this makes their circulatory system is more efficient and helps in maintaining constant body temperature.

Answer 2

ANSWER.

In human , blood flows through the heart twice for completing its circuit. This is called DOUBLE CIRCULATION. It includes ,

[1.] Pulmonary Circulation : - Circulation between lungs and heart. The deooxygenated blood pumped into the pulmonary artery is passed on to lungs from where oxygenated blood is carried by pulmonary veins into the left atrium .

[2.] Systematic Circulation :- Circulation between heart and various parts of the body. The oxygenated blood is passed through the aorta , arteries , Arteriole and capillaries and is reached the tissues. The deoxygenated blood collected from the tissues by venules, veins and vena cava is carried to the right atrium. The systemic circulation provides nutrients O2 and other essential substances to the tissues and takes CO2 and other harmful substances away for elimination.

¤¤ Its Significance :-

Oxygenated Blood and Deoxygenated Blood do not mix and circulate separately.