2.68: Understand How the Structure of Arteries, Veins and Capillaries Relate to their Function

ARTERIES, VEINS, CAPILLARIES
ARTERIES s Transports Oxygenated blood away from the Heart (excluding Pulmonary Artery) Thick muscular walls to withstand high pressure Narrow lumen to maintain high pressure to pump blood around the body
VEINS s Transports Deoxygenated blood towards the Heart (excluding the Pulmonary Vein) Thin walls to allow Skeletal muscle to exert pressure on Vein Wide lumen to transport large volume of blood Valves to prevent the backflow of blood under low pressure
CAPILLARIES s Facilitates material exchange between cells - e.g., gas exchange Thin walls (one cell thick) that are porous and permeable for efficient material exchange via diffusion Narrow lumen to fit between cells for extensive branching, which increases surface area to volume ratio for efficient material exchange via diffusion