One function of right ventricle is: It pumps deoxygenated blood through pulmonary artery to the lungs for oxygenation (purification). One function of left ventricle is: It pumps the oxygenated blood through pulmonary arteries to different parts of the body to supply oxygen for respiration.
Left ventricle needs to pump blood to all parts of the body whereas right ventricle needs to pump the blood only to the lungs for oxygenation. As the left side needs to pump the blood to a further distance it has thicker and more muscular wall to exert high pressure.
Contraction and relaxation of heart muscles in order to receive and pump blood one is called a heartbeat. A healthy adult's heart beats for about 60-100 times per minute. Heartbeat varies from person to person. The factors that affect the heartbeats are- age, sex, occupation, physical work, mental tension, etc.

The right part of the heart receives the impure blood whereas the left part of the heart receives the pure blood.

Aortic valve lies between the aorta and left ventricle. When the left ventricle squeezes, the valve shuts down and the blood flows forward. But if the valve is not present, the blood flows backward and its absence stops the blood circulation.
The heart is surrounded by two delicate membranes called pericardial membranes. Between these membranes, there is a fluid which is called pericardial fluid.
The functions of pericardial fluid are as follows: -
  1. It keeps the tissue of heart moist for proper functioning.
  2. It protects the heart from the mechanical shock and lessens the friction produced during heart beat.
  3. It acts as lubricant and reduces friction for the beating of heart.
Tricuspid valve Bicuspid valve
  1. It consists of three flaps.
  2. It is present in opening of right auricle and right ventricle.
  1. It consists of two flaps.
  2. It is present in opening of left auricle and left ventricle.
Right auricle collects the large amount of impure blood from different parts of the body through superior venacava and inferior venacava. In the left auricle, the less amount of pure blood is collected from the lungs through pulmonary vein. So, right auricle is bigger than left auricle.
The right ventricle has to pump blood for short distance i.e. from heart to the lungs. But the left ventricle has to pump blood for a very long distance inside our body, for which great pressure is required. Due to it, the wall of left ventricle is thicker than that of right ventricle.
  1. Aortic valve: It prevents the backflow of blood from aorta to the left ventricle, when the ventricles are relaxed.
  2. Pericardial fluid; It protects the heart from mechanical injury and shocks and also allows frictionless movements of the heart.
Veins contain valves which open toward heart. Valves are present in there to prevent back flow of blood. Thus, the blood does not flow in the wrong direction.