Exchange and Transport in Animals

The heart is a double pump with four chambers:
Right side: receives deoxygenated blood → pumps to lungs
Left side: receives oxygenated blood → pumps to body

Route: Vena cava → right atrium → right ventricle → pulmonary artery → lungs → pulmonary vein → left atrium → left ventricle → aorta → body

Left ventricle has a thicker wall (higher pressure needed for whole body).

Blood vessels: arteries (thick walls, away from heart), veins (valves, towards heart), capillaries (one cell thick, for exchange).

Coronary arteries supply the heart muscle itself with oxygenated blood. Blockages lead to heart attacks.