The Circulatory System

Main function: The transportation of materials to all body parts. Nutrients from digestion are carried to the cells and wastes are carried away from the cells to be eliminated from the body.

There are 2 pathways of blood flow:

1. Pulmonary circulation: blood moves from the right ventricle of the heart to the lungs where the exchange of gasses occurs. The red blood releases carbon dioxide and picks up oxygen. Veins from the lungs return the oxygenated blood to the heart.

2. Systemic Circulation: Oxygenated blood is push out of the left ventricle to all parts of the body. The blood supplies all necessary material for cells to function and removes the waste products.

Pathway of the Circulatory System:

In pulmonary circulation: Blood flows from the right ventricle, to the lungs, and back to the left ventricle of the heart.

In systemic circulation: Blood is pumped out of the left ventricle into the aorta. The Aorta is the main artery out of the heart. Arteries carry blood away from the heart and have high pressure. Arteries get smaller as they move away from the heart. Capillaries are the smallest blood vessels and are only a single cell thick. This is where the exchange of oxygen and carbon dioxide happens. Veins are blood vessels that return the blood back to the heart.