The heart is a muscular organ that pumps blood, Blood that contains waste materials is brought to the heart by blood vessels. This blood

enters the

and then moves down. The presence of the

prevents the backflow of blood inside the

heart

Blood enters the right atrium and then moves down the right ventricle. The presence of the valves prevent the backflow of the blood inside the heart.

Explanation:

Pathway of blood inside the heart:

Blood enters through right atrium, goes down to right ventricle.

From right ventricle to the lungs through the pulmonary artery

From the lungs to the left atrium through the pulmonary vein

From left ventricle to all parts through the aorta

The heart valves separate the heart chambers as well as prevent the backflow of blood back into the chamber from where it was pumped originally. Malfunctioning of heart valves leads to backflow or regurgitation of blood.

The heart valves are:

Atrioventricular valves - tricuspid and mitral valves auricular and ventricular chambers

Semilunar valves - pulmonary (between pulmonary artery) and aortic (between the aorta and left ventricle) valves

These valves prevent back flowing of blood in the following path:

Tricuspid valve - From right ventricle back into the right atrium

Mitral valve - From left ventricle back in to the left atrium

Pulmonary valve - From the pulmonary artery back into the right ventricle

Aortic valve - From the aorta back into the left ventricle