Describe the structure and working of the human heart .

Explanation

(I ) Heart is made up of cardiac muscle
(ii ) It is enclosed in a double walled sac called pericardium .
(iii ) It contains pericardial fluid , reduces friction during heart best .
(iv ) It is four chambered with two auricles and two ventricles
(v ) chambers are separted by partition called septum .
Working :
(i ) Heart is a muscular pumping organ that pumps out the blood into the blood vessels .
(ii ) the right and left pulmonary arteries supply deoxygenated blood to the lungs .
(iii) the oxygented blood is supplied by the aorta to various organs of the body .
(iv ) The cononary arterires supply blood to the heart .
(v ) Valves regulaate the flow of blood in a single direction and prevent back flow of blood