15 terms

Blood Vessels

vasa vasorum
system of tiny blood vessels in the walls of the larger vessels
provide nutrients and oxygen to the outer portions of the vessel
reduction in the lumen diameter as the smooth muscle contracts
increase in lumen diameter as smooth muscle relaxes
open space through which blood flows
spider-shaped smooth muscle-like cells that stabilize the capillary wall
intercellular cleft
gaps of unjoined membrane just large enough to allow limited passage of fluids and small solutes across the capillary wall
kupffer cells
large macrophages tat remove and destroy any contained bacteria
the flow of blood from an arteriole to a venule through capillary beds
precapillary sphincter
cuff of smooth muscle fibers that surround the root of each true capillary at the metarteriole
varicose veins
results from a leakage in the valves of veins typically in the lower limbs
venous sinuses
highly specialized, flattened veins thin thin walls composed of only endothelium
ex. coronary sinus and dural sinus
collateral channels
provide an alternate pathway for blood to reach a given body region
peripheral resistance
represents a measure of the amount of friction blood encounters as it passes through the vessels
the rising and falling of blood pressure due to the pulsing blood
vasomotor fibers
sympathetic fibers of the vasomotor centers that transmit relatively continuous impulses