HTN

Question 1

How does the renin-angiotensin-aldosterone system work?

Answer 1

• Renin is an enzyme secreted by specialized cells in the kidney when BP falls or decrease in sodium flowing through kidney tubules
• once in blood, renin converts to inactive liver protein (angiotensin I)
• when passing through lungs, angiotensin I is converted to angiotensin II (potent natural vasoconstrictors)
• angiotensin converting enzyme (ACE) finishes the process

Question 2

What is the renin-angiotensin-aldosterone system?

Answer 2

key homeostatic mechanism that controls BP and fluid balance

Question 3

Angiotensin II

Answer 3

• potent natural vasoconstrictor

- secretes ADH and aldosterone

Question 4

Aldosterone

Answer 4

hormone from adrenal cortex

increases sodium reabsorption in the kidneys

helps the body retain water (increases blood volume and raises BP)

Question 5

ADH

Answer 5

hormone from posterior pituitary

enhances the conservation of water by the kidneys (increases BP by increasing blood volume)

Question 6

Angiotensin-converting enzyme (ACE) inhibitors

Answer 6

Block the affects of angiotensin II and aldosterone levels to decrease BP by lowering peripheral resistance and decreasing blood volume

Question 7

Angiotensin II receptor blockers (ARBs)

Answer 7

block receptors for angiotensin II in arteriolar smooth muscle and in the adrenal gland

causes BP to fall

arteriolar dilation and increases sodium excretion by the kidneys

(different from ACE inhibitors because it blocks the action of angiotensin II after it is formed)

Question 8

Hypertension

Answer 8

consistent elevation of systemic arterial BP

Question 9

Primary, idiopathic or essential HTN

Answer 9

no identifiable cause

90%

Question 10

Secondary HTN

Answer 10

caused by identifiable factors

ex. excessive secretion of epinephrine by the adrenal glands or by narrowing of the renal arteries

10%

Question 11

Non pharmacological tx of HTN

Answer 11

● Exercise
● Diet
● Smoking cessation
● Alcohol intake

Question 12

Nutritional therapy of HTN

Answer 12

● DASH diet (dietary approaches to stop hypertension)
● Low in saturated fat, total fat, and cholesterol
● High in fruits, vegetables, and low fat dairy foods
● Whole grains, poultry, fish, and nuts
● Low amounts of fats, red meats, sweets, and sugared beverages
● High in potassium, calcium, magnesium, protein and fiber
● Lower in salt and sodium
○ Sodium circulating in blood, higher BP

Question 13

Recommendations for HTN

Answer 13

maintenance of healthy weight (weight loss is recommended for those who are overweight)

moderate activity increases strength of heart to improve BP

Question 14

Factors that affect BP

Answer 14

• peripheral resistance
• fluid volume
• cardiac output

Question 15

Cardiac output

Answer 15

volume of blood pumped per minute

higher CO = higher BP

CO determined by HR and stroke volume (amount of blood pumped by a ventricle in one contraction)

Question 16

Peripheral Resistance

Answer 16

turbulence-induced friction in the arteries

Question 17

Peripheral Resistance

Answer 17

turbulence-induced friction in the arteries

Question 18

Baroreceptors

Answer 18

sense pressure within large vessels

Question 19

Chemoreceptors

Answer 19

recognize pH levels of oxygen and CO2 in the blood

Question 20

Stress

Answer 20

causes BP to rise

Question 21

Depression, lethargy

Answer 21

BP lowers

Question 22

Systolic BP

Answer 22

pressure in the arteries when the ventricles in the heart contract

Question 23

Diastolic BP

Answer 23

When the pressure falls from the ventricles relaxing and not ejecting blood

Question 24

Risks

Answer 24

When BP rises, the heart has to work harder to eject blood into the circulation

causes

• ventricular hypertrophy (thickening of vessel walls)
• angina, MI, CVA, peripheral vascular disease
• HF
• Kidney failure
• blindness

Question 25

Guidelines to management of HTN

Answer 25

healthy BP is in the 115/75 range

first approach is a modifiable lifestyle

if pressure does not change… drugs can be added

Question 26

Pharmacotherapy of HTN

Answer 26

Diuretics, ACE inhibitors, Angiotensin II receptor blockers, calcium channel blockers, beta-blockers

then… added vasodilators or alpha 2 agonists

used to reduce morbidity and mortality

individualized to pts risk factors, comorbid med conditions and degree of BP elevation