Vessel Layers
What are the three layers of blood vessels from outermost to innermost?
tunica externa (adventitia), tunica media, tunica intima
What are the three types of arteries from largest to smallest?
what are the three types of capillaries from most to least permeable?
sinusoidal, fenestrated, continuous
What is the formula for pulse pressure?
systolic pressure - diastolic pressure
average blood pressure (include units)
120/80 mmHg
Where would the tunica media be thickest?
muscular arteries
the blood reservoir
veins
what is the function of pericytes?
stabilize capillary walls and control permeability
what are the three sources of resistance?
blood viscosity, vessel length, vessel diameter
what branch of the ANS controls vasoconstrictionof blood vessels?
sympathetic
what tunic is the vasa vasorum located and in what type of vessels can you find them?
Tunica externa
Bigger/major blood vessels
Where are elastic arteries found and what specific characteristic is important regarding their location?
located close to the heart
recoil allows for them to manage the high pressure coming from heart contraction
What type of capillaries are bet fit for absorption and filtration?
fenestrated capillaries
Where does the greatest change in blood pressure occur?
arterioles
why are valves important in the venous system?
prevent backflow since there is too low a pressure to push blood in the right direction
What is the function of the tunica intima?
reduces friction and contains subendothelial layer of connective tissue (basement membrane)
What important role to arterioles play in the control of blood pressure?
arterioles vasoconstrict to lower blood pressure and slow down blood so that the blood does not cause capillaries to burst
why are continous capillaries important to have in the brain?
create blood brain barrier
walls are not permeable enough to let blood leave the capillaries, but nutrients, gases, and ions can still pass through the intercellular clefts
What is blood pressure when it reaches the right atrium? (include units)
0 mmHg
how does blood vessel diameter influence resistance?
varies inversely with 4th power of vessel radius
if radius is doubled, the resistance is 1/16 as much
vasoconstriction->increased resistance
Why are there collagen fibers in the tunica external?
anchor vessels to surrounding structures
describe respiratory pump for venous return
pressure changes during breathing move blood toward the heart by squeezing abdominal veins at the diaphragm pushes on abdominal caivty
what three structures control the flow through the capillary beds?
metarteriole, thoroughfare channel, and precapillary sphincters
what is the formula and definition of MAP?
mean arterial pressure- pressure that propels blood to the tissues
MAP=diastolic pressure + 1/3 pulse pressure
the name of the alternate pathways to given body regions