Introduction to the Circulatory System

Where does blood go? Blood vessels carry blood to every part of the body Blood carries oxygen and nutrients to all the parts of the body Blood carries carbon dioxide and waste away from the body Basic pathway… Heart-arteries-capillaries-veins-heart

From blood to the body… Materials transfer from the blood to the body in 2 ways: –Diffusion When materials go from an area of high concentration to an area of lower concentration –Active Transport Requires energy because material moves from an area of low concentration to an area of higher concentration

Blood Vessels Arteries (carry Away from the heart) Veins (carry To the heart) Capillaries (Connect arteries and veins)

Arteries Carry blood away from the heart 3 Layers –Connective Tissue –Smooth Muscle –Elastic Connective Tissue Aorta – major artery the supplies blood to the body

Veins Carry blood back to the heart 3 layers –Connective tissue –Smooth muscle –Elastic Connective Tissue Have one way valves that keep blood from flowing backward Superior vena cava – blood from the head and neck Inferior vena cava – blood from the abdomen and lower body

Capillaries Connect arteries and veins Only one cell thick Diffusion of nutrients and wastes occurs across this barrier