Describe double circulation in human beings. Why is it necessary?
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
Systemic Circulation:
During systemic circulation, oxygenated blood from left atrium is supplied to the left ventricle, from where blood is pumped to various parts of the body. The deoxygenated blood is collected from the various body organs by the veins and brought into the vena cava and finally into the right atrium. Right atrium transfers the blood into the right ventricle.
Pulmonary Circulation:
The deoxygenated blood is pumped by the right ventricle into the lungs for oxygenation. The oxygenated blood is brought back to left atrium (auricle) of the human heart by means of four pulmonary veins. From the left atrium, the oxygenated blood is pushed into the left ventricle. The left ventricle pumps oxygenated blood into the aorta for systematic circulation.
This type of double circulation is necessary in human beings to separate oxygenated and deoxygenated blood as this enhances the efficiency of cellular respiration in humans and consequently helps in maintaining a constant body temperature.
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
Systemic Circulation:
During systemic circulation, oxygenated blood from left atrium is supplied to the left ventricle, from where blood is pumped to various parts of the body. The deoxygenated blood is collected from the various body organs by the veins and brought into the vena cava and finally into the right atrium. Right atrium transfers the blood into the right ventricle.
Pulmonary Circulation:
The deoxygenated blood is pumped by the right ventricle into the lungs for oxygenation. The oxygenated blood is brought back to left atrium (auricle) of the human heart by means of four pulmonary veins. From the left atrium, the oxygenated blood is pushed into the left ventricle. The left ventricle pumps oxygenated blood into the aorta for systematic circulation.
This type of double circulation is necessary in human beings to separate oxygenated and deoxygenated blood as this enhances the efficiency of cellular respiration in humans and consequently helps in maintaining a constant body temperature.
