three major types of vessel
arteries, capillaries, and veins
— carry blood away from the heart, — carry blood toward the heart
arteries; veins
contact tissue cells and directly serve cellular needs
capillaries
wall of arteries and veins are composed of three tunies
tunica externa, tunica media and tunica interna (intima)
tunics
wall has 3 layers
tunica externa
tunica media
tunica interna
arteries
2 types of arteries
elastic (conducting) arteries and muscular arteries
larger arteries
elastic (conducting) arteries
medium to smaller arteries
muscular arteries
elastic arteries
muscular arteries
atrioloes
capillaries
on the outer surface help stabilize capillary walls
pericytes
contractile cells that wrap around the endothelial cells of capillaries and venules
pericytes (rouget cells or mural cells)
are abundant in the skin and muscles
continous capillaries
fenestrated capillaries
sinisoids
capillary beds consist of two types of vessels
vascular shunts and true capilliaries
consist of metarteriole–thoroughfare channels connecting an arteriole directly to a venule
vascular shunts
10 to 100 per capillary bed
true capillaries