Brand 12/1/08 Arterial Pressure Utcom

Front 1

where are high and low pressure baroreceptors? which nerves cary their signals?

Back 1

high - carotid sinus, aortic arch
low - atrium, vena cava
they travel up CN IX and X

Front 2

what parts of the brain are the major BV excitatory/inhibitory centers

Back 2

all messages converge at vasomotor center in medulla/pons
receives signals from:
ant hypothal - inhibitory
post hypothal - excitatory

Front 3

list the pressure ranges that dif baroreceptors act

Back 3

Carotid Sinus - 60-180. (most significant one in regulating the normal range)
Aortic Arch - 90-210
Peripheral chemoreceptors work during low BP, <80
CNS Ischemic response is a last-choice response, <20, where high CO2 leads to high sympathetic stimulation

Front 4

explain capacitance veins

Back 4

veins in the visceral organs, but not VC, constrict upon sympa stimulation which releases their "stores" of blood and transfers it to rest of system

Front 5

describe autonomic failure, eg sp. cord injury, and HR/BP

Back 5

arterial pressure will decrease by 50%. thus SV will increase, thus PP will increase, but the pressures will be very errant

Front 6

describe vasovagal syncope

Back 6

the ant hypothal (inhibitory signals) signals decrease HR and CO, also vasodilate skeletal mm, less TPR, lower BP, faint

Front 7

why do some people faint after a meal?

Back 7

after eating, GI flow increases, and peripheral resistance should increase to balance the TPR. in elderly, peripheral resistance may not increase, so their TPR will drop, and MAP will decrease

Front 8

describe diuresis and natriuresis

Back 8

diuresis is increased urine flow
natriuresis is increased Na excretion
both help to reduce BP

Front 9

how does angiotension work?

Back 9

reduces Na excretion by kidney to retain H2O and maintain BP

Front 10

how does renal fxn relate to the pressure-diuresis curve?

Back 10

as renal fxn gets worse, Na excretion decreases, so BP may increase - leading to chronic HTN