Arteries Veinsover-all diameter less greater

lumen smaller largerwall thicker; more rigid thinner; less rigid

relationship of diameter of lumen→the thickness of

the wall

less *except in large arteries

relatively larger lumen(?)

3 coatsbetter demarcated &distinguishable

often lack distinct boundaries

tunica intima relatively thicker relatively thinner

internal elastic membrane presentpresent only in bigger veins; never prominent

smooth muscles&elastic tissue

better supplied

lesser amount; prominent only in larger veins; fibrous (collagenous) tissue occurs in much greater quantities

thickest coat tunica media tunica adventitia

relationship of TATM

thinner *except in med-sized

arteries=equal/almost equal

valves X

*esp those of the lower extremities to prevent backflow of blood

vasa vasorum fewermore; extend more deeply through the media&into

the TI

blood flowmore rapid;under high

pressureslower; under low

pressure

nourishment of cells of inner layers of wall

diffusion mechanisms-operate over long

distances

diffusion mechanisms-operate only over short

distances