kidney ch19 med prep

pressure diuresis

an increase in arterial pressure by only a few mmHg cann double the renal output.

pressure natriuresis

an increase in arterial pressure by only a few mmHg cann double the salt output.

renal perfusion

the blood flow that passes through a unit mass of renal tissue within a given time

near-infinite-feedack gain priciple

the return of arterial pressure always back to the equilibrium point in the rena urinary output curve.

what are the 2 factors which can change the equilibrium position of the renal output curve?

1) the degree of pressure shift of the renal output curve for water and salt

2) the water and salt intake level

antinatriuretic horomones

hormones which increase reabsorption of sodium, resulting in increased blood volume, increasing blood pressure..

what causes salt sensitivity?

• kidney damage or excess secretion of antinatriuretic hormones like angiotensin 2, aldosterone, ANP, ADH

where is adh secreted

it is secreted by the hypothalamus specifically the posterior pituitary gland

renal ischemia or renal secreting tumor

renin secreting tumor results in large amount of angiotensin 2 formation which leads to vasoconstriction and increased sodium and water retention.

one kidney golbatt hypertension

when one kidney is removed a constrictor is placed on the renal artery of remaining kidney, this leads to decreased pressure inn the renal artery beyond the constrictor , this stimulates rapid release of renin,this increases the ystematic arterial pressure . this is evident in patients with stenosis