The Heart and Blood Circulation

The Heart and Blood Circulation

The heart is a four chambered muscular pump around the size of a fist.

It beats about 100,000 times a day pumping around 2,000 gallons of

blood through about 100,000 miles of organic tubing.

The heart is a big muscle with four valves connected together to make

a two-stage pump. The heart gets its energy by oxidizing blood sugars.

This released energy, contracts the heart’s many muscle cells, and the

four chambers squeeze blood out into the arteries.

The arteries are thick walled muscular tubes which carry blood away

from the heart. The heart has two sides - the left ventricle and the

right ventricle. The artery from the right ventricle pumps blood to

the lungs, this is called the pulmonary artery and it is the only

artery that carries deoxygenated blood. The artery from the left

ventricle pumps blood to the rest of the body and it is called the

aorta.

Veins are thin walled tubes which carry blood back to the heart, they

have a large diameter and valves. The veins retur...