hypertension

Question 1

What is the definition of hypertension

Answer 1

persistently higher than normal blood pressure, treatment if mean BP> 150/95 mmHg

Question 2

What is the equation for BP

Answer 2

BP= COTPR where CO=SVHR and TPR is a measure of the degree of constrictions of the arterioles.

Question 3

Outline sympathetic regulation of BP

Answer 3

see notes on hypertension

Question 4

How does the sympathetic system increase the frequency and force of contraction

Answer 4

via B1 receptors, increases cAMP which increases CA2+ that increases there’s and force of contraction

parasympathetic activity decreases frequency by decreasing cAMP via M2 receptors.

Question 5

How is TPR regulated

Answer 5

SNS—>NA—>a1—1p3—->ca2+—->constriction

SNS—>A—->B2—->cAMP—–>relaxation

Question 6

How does RAAS regulate BP

Answer 6

A decrease in BP causes the kidneys to secrete renin which turns angiotensinogen (secreted by the liver) to angiotensin 1 that is turned to angiotensin 2 by ACE (secreted by the lungs) which signals aldosterone secretion that increases the uptake of salts and therefore increases water uptake which increases BP.

Question 7

What are some side effects of ACEi

Answer 7

ACE inhibitors increase angiotensin 1 which along with an increase in substance p bradykinin increase respiratory tract sensitivity.

renal impairment due to hypotension and may cause hyperkalemia. ramipril is an ACEi

Question 8

What is an example of angiotensin receptor antagonist

Answer 8

Losartan, has minimal side effects

Question 9

What is an example of an aldosterone antagonist

Answer 9

spironolactone can be used as an add on for resistant hypertension but frontline in patients with primary aldosteronism.

Question 10

What is an example of calcium channel antagonist

Answer 10

amlodipine, targets L-type calcium channel on the smooth muscle of arterioles, can be used to decrease the frequency and force of contraction.

Question 11

What are some examples of diuretics that are used in bp regulation

Answer 11

thiazide and thiazide like diuretics as they also acts via activation of Katp in smooth muscle of blood vessels to dilate arterioles and decrease BP.

Question 12

Outline the function of indapamide

Answer 12

opens Katp channel so K+ leaves which makes the voltage more negative which makes the VGCC less likely to open so the smooth muscle relaxes and BP goes down.
S/E: hypokalemia and decreased ions, increase in urate, glucose and blood lipids.

Question 13

How does thiazide and thiazide-like diuretics decrease hypertension

Answer 13

they block the reabsorption of sodium in the DCT which stops water following, this decreases blood volume and as a result blood pressure.