it is a muscular organ which pumps the blood through the blood vessels.Blood provides oxygen and nutrients to the body.
The tissues of the body need a constant supply of nutrition need to be active
In humans, the heart is the size of a large fist and weights between about 280 to 340 grams in men and 230 to 280 grams in women
The human heart has four chambers: two upper chambers and two lower.
The right atrium and right ventricle together make up the “right heart,” and the left atrium and left ventricle make up the “left heart.” A wall of muscle called the septum separates the two sides of the heart.
A double-walled sac called the pericardium encases the heart, which serves to protect the heart and anchor it inside the chest. Between the outer layer, the parietal pericardium, and the inner layer, the serous pericardium, runs pericardial fluid, which lubricates the heart during contractions and movements of the lungs and diaphragm.
The heart’s outer wall consists of three layers. The outermost wall layer is the inner wall of the pericardium. The middle layer, or myocardium, contains the muscle that contracts. The inner layer is the lining that contacts the blood.