Explain working of heart for class 7as per symbiosis school NCERT
Answers
he human heart is an important muscular organ involved in pumping blood to different parts of the body with the help of three segments of the circulatory system:
The pulmonary circulation ( heart and lungs ),
The systemic circulation (body systems) and
The coronary circulation (blood vessels of the heart).
The coronary circulation is an essential system to the heart as it circulates blood from the main artery – that comes from the heart. It also plays a vital role in supplying oxygen, nutrients and removing carbon dioxide and other wastes through the circulatory system.
The human heart is about the size of our 0wn fist and is mainly divided into four chambers namely two ventricles and two atria. The ventricles are the chambers that pump blood and atrium are the chambers that receive blood. Among which both right atrium and ventricle make up the “right heart, and the left atrium and ventricle make up the “left heart.” The right and the left region of the heart are separated by the wall of muscle called septum. The right ventricle pumps the blood to the lungs for re-oxygenation when it gets filled up by the pulmonary arteries. The right semilunar valves close and prevent the blood from the pulmonary veins after blood passes through the pulmonary arteries. Then the oxygenated blood is received by the left atrium from the lungs via pulmonary veins.