Chapter 15 - Blood Flow/BP Flashcards
cardiac output
total blood flow at any level of the circulation
metarterioles regulate blood flow through capillaries by contraction and dilation of…
precapillary sphincters
the site of exchange b/w blood and interstitial fluid
capillaries and postcapillary venules
pulse pressure
systolic pressure minus diastolic pressure
mean arterial pressure (MAP)
diastolic pressure + 1/3 (systolic pressure - diastolic pressure)
the main site of variable resistance in the systemic circulation
arterioles
relationship b/w resistance and radius of an arteriole
a small change in the radius of an arteriole creates a large change in resistance: R is proportional to 1/r^4
myogenic autoregulation
how arterioles regulates their own blood flow. vasoconstriction increases the resistance offered by an arteriole and decreases the blood flow through the arteriole
vasodilator paracrine molecules include:
NO, H+, K+, CO2, prostaglandins, adenosine, histamine. low O2 also causes vasodilation.
endothelins are powerful…
vasoconstrictors
active hyperemia
a process in which increased blood flow accompanies increased metabolic activity
reactive hyperemia
an increase in tissue blood flow following a period of low perfusion
the reflex control of BP resides in the …
medulla oblongata
baroreceptor reflex
the primary reflex pathway from homeostatic control of mean arterial BP. baroreceptors in the carotid artery and the aorta monitor arterial BP and trigger this reflex
continuous capillaries
have leaky junctions b/w cells but also transport material using transcytosis. continuous capillaries w/ tight junctions form the blood-brain barrier
