Question

• Compare and contrast the structure, mechanical properties, and functions of arteries, arterioles, capillaries, venules, and veins in the cardiovascular system.

Answer 1

Answer :- Arteries: Carry blood from heart toward the tissues of organs. Carries oxygen rich blood, contains all three layers; thick tunica media, thinner tunica externa than veins. They stay rounded, have contractibility, and are ANS responsive

arterioles:
smaller branches that enter tissues
Move blood from main artery into capillaries.
tunics size decreased relatively
most ANS responsive
vasoconstrict and vasodilate to controlling BP
point at which vessels become microscopic vessels
form anastomoses for collateral circulation

veins:
return vessels that take deoxygenated blood back to the heart
has all three layers but with a thinner tunica media and a thicker tunica externa
entire wall is thinner than arteries; widely distended; weak walls
BP is greatly reduced
contain valves to prevent back flow especially in extremities
serve as blood reservoirs
some sympathetic stimulation causing veins to vasoconstrict to divert blood to skeletal muscles instead of pooling
in hemorrhage venous blood can replace lost blood

venules:
return vessels that take deoxygenated blood back to the heart
only two layers; tunica interna and tunica externe
BP is greatly reduced

capillaries: exchange happens between the capillaries and the cells of tissues via simple diffusion and blood plasma
made of only tunica interna
only one epithelial cell thick
near every cell in body
microscopic
number per tissue depends on activity level in that tissue (oxygen and nutrient demand)
form capillary networks which increase surface area for diffusion....Thanks dear student