GROSS ANATOMY

Detailed explanation-1: -The heart consists of four chambers in which blood flows. Blood enters the right atrium and passes through the right ventricle. The right ventricle pumps the blood to the lungs where it becomes oxygenated. The oxygenated blood is brought back to the heart by the pulmonary veins which enter the left atrium.

Detailed explanation-2: -The left atrium receives oxygen-rich blood from the lungs and pumps it to the left ventricle through the mitral valve. The left ventricle pumps the oxygen-rich blood through the aortic valve out to the rest of the body.

Detailed explanation-3: -Oxygen-rich blood flows from the lungs back into the left atrium (LA), or the left upper chamber of the heart, through four pulmonary veins. Oxygen-rich blood then flows through the mitral valve (MV) into the left ventricle (LV), or the left lower chamber.

Detailed explanation-4: -The heart has four chambers. The upper two chambers are the atria, and the lower two are the ventricles (Figure A). The chambers are separated by a wall of tissue called the septum. Blood is pumped through the chambers, aided by four heart valves. The valves open and close to let the blood flow in only one direction.

Detailed explanation-5: -The atrium was formerly called the ‘auricle’. That term is still used to describe this chamber in some other animals, such as the Mollusca. They have thicker muscular walls than the atria do.