Circulation of Blood

Topic Content:

The flow of blood around the body is known as blood circulation. The circulation of blood is caused by the pumping action of the heart. Pressure usually fluctuates with the heartbeat. The pressure wave can be felt as a pulse or heartbeat. In mammals, blood flows in circuits. Blood passes through the heart twice in one circulation.

Heartbeat:

It can occur in two stages; diastole and systole.

Diastole:

This is the first stage of the heartbeat. The series of events that happen during diastole can be summarized below.

i. Blood enters the atria of the heart through the vena cava creating a high pressure in the blood contained in them.

ii. The pressure forces the valves, the bicuspid and the tricuspid valve, to open into