blood vessels final

arteries

structure- thick muscular walls

function- carry blood away from heart under high pressure

veins

structure- thinner walls, valves prevent backflow

function- carry blood toward the heart under low pressure

capillaries

structure- very thin walls

function- site of gas, nutrient, and waste exchange between blood and tissues

blood vessel diameter

narrower vessels increase resistance and pressure

blood viscosity

thicker blood (dehydration) increases resistance

vessel length

longer vessel increases resistance

cardiac output

more blood pumped=higher pressure and flow

elasticity of vessels

more elastic arteries maintain better pressure control

filtration

movement of fluid out of capillaries into tissues

• driven by hydrostatic pressure (pushing force from blood pressure)

reabsorption

movement of fluid back into capillaries

• driven by osmotic pressure (pulling force due to plasma proteins)