Blood Vessels

Arteries Carry blood away from the heart to other parts of the body. Structure: walls of arteries are thick Epithelial cells create a smooth surface on the inside. Muscle tissue regulates how much blood is sent to other organs Flexible connective tissue surrounds the artery. Strong and Flexible!

Capillaries Where materials (oxygen, glucose) is exchanged between blood and body cells. Structure: Epithelial tissue only 1 cell thick Allows materials to easily pass through.

Veins Carries the oxygen-poor blood back to the heart. Structure: same as the arteries. Muscle tissue is much thinner. Skeletal muscles help push blood along. Valves in large veins prevent blood from flowing backwards.

Why do you think it is important for the arteries to be thicker? Arteries adjust the amount of blood flowing to different parts of the body, depending on where blood is needed. Use this fact to explain why you should not exercise vigorously shortly after you eat?