cardiovascular lecture 5 Flashcards
perfusion pressure/delta P is the same for
all vascular beds
delta P equals
MAP-VP
organs with the lowest resistance receive
the highest flow. F=delta P/R…since delta P is the same for all vascular beds/organs, R is the major determinate
how do you decrease resistance in vascular beds
relaxation of smooth muscle…mostly in arterioles bc they have the most smooth muscle and also the most resistance
if you decrease MAP what happens to flow
flow decreases. MAP DETERMINES BLOOD FLOW
what is the equation for MAP
MAP= Cardiac Output x Total Peripheral Resistance . So MAP is a result in changes in C.O and TPR
TPR can be changed by…
vasodilation/vasoconstriction of arterioles. compensatory changes in this arteriole resistance occurs to PROTECT THE MAINTENANCE OF MAP
Blood loss causes MAP to do what
MAP decreases with decrease in blood volume. A drop in blood volume decrease blood back to the heart which ultimately causes a decrease in stroke volume which then causes a decrease in C.O and bc MAP=C.O x TPR, a decrease in C.O, decreases MAP
MAP is pressure in the …..
aorta…all of body receives blood from here
what do baroreceptor neurons do
senseor MAP by monitoring pressure in the aortic arch and carotid sinuses
the a.p frequency of baroreceptors is proportional to….
MAP….an increase in pressure causes increased stretch and increased a.p firing…and vice versa
and increase in baroreceptor firing causes what in the symp and psymp
increase in firing means there was an increase in MAP, so body wants to decrease MAP by decreasing C.O/h.r. So, symps will decrease and psymps will increase.
where do baroreceptors send signals to initially
CVCC (in medulla oblongata/brain) and then out to heart/arterioles/veins
