Question

explain transportation of blood in human beings

Answer 1

TRANSPORTATION:

When the heart is being filled with blood (whether from the body or the lungs), this is called the diastole. When the heart is pumping the blood out of it (whether to the body or to the lungs), it is called the systole.

During diastole, the heart is getting filled with blood, the blood enters the atria first, the atria contract to force blood into the ventricles, both tricuspid and bicuspid valves are open to allow blood into the ventricles and the semilunar valves are shut. Once the ventricles get filled with blood, it is systole, the bicuspid and tricuspid valves get shut and semilunar valves are open, the ventricles contract strongly forcing the blood into the Aorta or pulmonary artery.

During diastole, the semilunar valves are shut to keep the blood out of the arteries. During systole the tricuspid and bicuspid valves are closed, to prevent blood from flowing back into the atria when it is pumped. The tricuspid and bicuspid valves are kept fixed by fibres called tendons, they prevent the valves from opening in the opposite direction, allowing backflow.The human transport system is a system of tubes with a pump and valves to ensure one-way blood flow.