Heart and Blood Structures and functions: Atria (sing = atrium) – receive blood from the body (veins) Ventricles – pump blood out of the heart via arteries

Myocardium – involuntary, striated muscle Heart Layers Myocardium – involuntary, striated muscle Endocardium – innermost layer, develops from endothelial cells that line blood vessels, protects Epicardium – membrane that forms inner layer of pericardium and outer layer of the heart

Blood Vessels: Arteries – carry blood FROM the heart Arterioles – smaller, branching vessels from arteries Capillaries – small, narrow vessels. SIGHT OF DIFFUSION Veins – carry blood TO the heart Venules – smaller, branching vessels, collect blood from capillaries and send to veins

Diagram Complete the heart diagram and blood flow If not done, it’s homework. 50 pts