autonomic BP regulation Flashcards
what is formula for MAP
HRSVTPR+Pveins
what are 2 effects of symp activation on TPR
- constriction of resistance vessel in skin, GI, genitals via NA and a-receptors
- dilatation of vessels in heart and skeleton (B2)
what is autonomic response to drop in BP
constrict vessels to raise BP
where in particular does autonomic influence change vessel radius
muscular arterioles
how else does sypm activation increase MAP
increases HR > more CO
how does system know when MAP changed
baroreceptors in cartid sinus
what happens to signalling when BP gets too high
send more rapid APs back to control centre
where is control centre
medulla
what are transmitters for para and symp system
para -ACH
symp - NA
what is orthostatic hypotension
stand up quick and pass out because blood not going to brain
what normally controls stopping of orthostatic pressure
baroreceptors read and contrict vessels to incr. BP
what shift occurs when we eat a large meal
blood goes from art to Vein
what is intrinsic response to big meal (2)
higher preload = more CO
lower afterload = more CO
what is extrinsic reponse to big meal
- higher TPR
- lower vein comliance > higher vein P
- higher HR and leftward ESPVR
what happens to Part for 24 hrs after excercise
reduced for about 24hrs
