Phys 23: Long Term Control Of Bp

Front 1

Describe the shape of a salt sensitive hypertensive renal function curve compared to that of a normal

Back 1

The hypertensive will start at a higher equilibrium point. In the normal, an increase in salt intake will not result in a large increase in pressure so the curve rises nealyly vertically. In the salt sensitive, an incrase in salt will increase pressure so the curve shifts right as it rises.

Front 2

Explain how the cause of hypertension change from the acute to the chornic phase in volume loading hypertension w/ decreases renal mass

Back 2

Intially, the volume load increases cardiac output which leads to an increase in arterial pressure. In response to the increase in CO and the increase in blood flow to tissues, the body autoregulates and decreases CO by increaseing TPR. The increase in TPR functions to maintain the elevated arterial pressure. Note well-the increase TPR is a result of hypertension not the cause in this situation.

Front 3

Explain how increased ECF leads to increases arterial pressure (cascade)

Back 3

increase ECF=> increased blood volume=> increased Psf=> increased venous return=> increase cardiac output => autoregulation and increased TPR, increased CO and TPR=> increased arterial pressure

Front 4

What does the Goldblatt renal artery clamp experiment demonstrate

Back 4

clamping the renal artery decreases the pressure sensed by the kidney which triggers the renin/angiotensinogen system. This system works to increase arteriole pressure by increaseing vasconstriction and by increasing Na/H2O retention. This mechanism can raise arteriole pressure beyond the normal level until a pressure is acheived that will allow the kidney to filter properly again. Think in terms of the kidney being selfish, it will set BP at what it needs, not the body.

Front 5

What do the results of the renal cross transplantation studies demonstrate

Back 5

transplanting a hypertensive kidney into a normal rat can lead to hypertension and visa versa, demonstrates that the kidney is main determiner of blood pressure

Front 6

Describe the cascade that occurs to activate the renin-angiotensinogen system

Back 6

a decrease in blood pressure signals to the kidney to release renin. renin acts on angiotensinogen converting it to angiotension I. Angiotensin I is converted to angiotensin II by ACE. Angiotension II increases blood pressure by increasing renal retention of salt and water and increasing vasconstriction.

Front 7

expalin how angiotensinogen production changes to maintain a normal BP at varous sodium intake levels

Back 7

When Na intake is high, angiotensin production is low and Na exrection will be favored. The curve is shifted far left. When Na intake is low, angiotensin production will be high and Na retention will be favored. The curve is shifted far right.