explain double circulation in human
Answers
Double circulation
The human circulatory system is a double circulatory system. It has two separate circuits and blood passes through the heart twice:
the pulmonary circuit is between the heart and lungs
the systemic circuit is between the heart and the other organs
Pulmonary circulation takes place between the heart and the lungs Systemic circulation takes place between the heart and other organs
Pulmonary circuit
The pulmonary circuit transports blood to the lungs. The blood is oxygenated there and then carried back to the heart. Gaseous exchange happens in the lungs:
carbon dioxide diffuses from the blood into the air in the alveoli
oxygen diffuses from the air in the alveoli into the blood, and is absorbed by haemoglobin in the red blood cells
Unlike other arteries and veins, the pulmonary artery carries deoxygenated blood and the pulmonary vein carries oxygenated blood.
Systemic circuit
The systemic circuit transports blood around the body. It transports oxygen and nutrients to the body tissues, and carries away deoxygenated blood containing carbon dioxide and other waste materials.
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.