Explain Circulation in humans .

Explanation

Circulation in human beings was discovered by Willian Harvey. In the cardio vascular system human heart works like a double pump. The right half receives and pumps deoxygenated blood and the left half receives and pumps oxygented blood. This type of circulation is called circulation and it involves a shorter pulmonary circulation and a long systemic circulation .
1. Pulmonary circulation : It includes collection of deoxygented ( impure) blood into the right side chambers of the heart. Then pumping the same into lungs for oxygenation and bringing back the oxygenated blood from the lungs into the left atrium.
The superior vena cava and inferior vena cava, collect the impure blood into the right atrium from anterior and poster regions of the body respectively. Now, it is pumped into the right ventricle. This in turn pumps the blood to the lungs through the pulmonary artery. Blood exchanges carbon dioxide for oxygen int he capillaries of the alveoli. Thus the blood gets oxygenated . The purified blood leaves the lungs through pulmonary veins, which open into left atrium. So the left atrium receives pure blood from the lungs.
2. Systemic circulation : This includes collection of oxygenated blood from lungs into the left atrium. The left atrium pumps the oxygenated blood into the left ventricle, which shows powerful contractions. Blood is pumped into aorta with a definite pressure. Aorta gives off various branches in different regions for the distribution . Blood exchanges oxygen for carbon dioxide in the tissues of the body. Thus blood is again deoxygenated . This deoxygenated blood is collected by superior venacava and inferior venacava and poured into right atrium.