Kidneys roll in circulation

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What is kidneys roll in blood pressure?

Increased bp -> increased diuresis and natriuresis -> Decreased BV

What is pressure diuresis/natriuresis?

A few mm hg increase -> doubles the effect of renal output.

What is the two primary determinants of the long-term arterial pressure level?

Shifting the equilibrium point. That is to change the intake/outtake level in ren.

Decribe the arterial pressure in kidney.

CO and peripheral resistant changes while arterial pressure in ren is constant.

Define hyper tension.

Blood pressure s>135 d>90

Hypertension causes?

1) heart failure and coronary heart disease 2)increased bp-> cerbral infarkt (stroke) 3) increased bp-> hemorrage in ren

Hypertension is caused by?

Excessive accumulation of extracellular fluid in the body.

Describe changes in circulary function during volume-loading hypertension!

1) increased extracellular fluid volume-> increased blood volume -> increased CO -> increased bp actives baroreceptors-> Vasodilatation -> decreased resistance

Why does kidney failure cause high pressure?

Kidney can't secrete salt -> hypertension

Salt causes?

1) Stimulation of thirst center in medulla.

What is the salts effect on renin-angiotensin system?

Increased salt intake->Increased ECV-> Increased BP-> Decreased renin & angiotensin-> decreased retention of salt and water-> Return of ECV back to normal-> normal BP

Why does aldesteronism lead to hypertension?

Tumor or patological disorder in adrenal gland -> increase alderone release-> increased salt&water absorbtion ->hypertension

Describe the renin-angiotensin system!

dec. bp->prerenin (stored in juxta glomeruler cells) ->renin (func. enzym) -> angiotensin-I (have a little vasoconstrion effect)-> angiotensin-II (lungs)

What does angiotensin-II (prod. lungs) have for effect?

1)Vasoconstricter (arteriols and little on veins) 2)retention of water & salt (because of renvasoconstrion and better absorbtion) 3) release of aldorone (causes better absorbtion in ren)