Lecture 13 - Control of Blood Flow II

Question 1

What are characteristics of hypertension?

Answer 1

• increased cardiac output
• increased sympathetic nerve activity
• increased angiotensin II and aldosterone levels
• impairment of renal-pressure natriuresis mechanism
• inadequate secretion of salt and water

Question 3

What is primary hypertension?

Answer 3

-hypertension of unknown origin
-90-95% of hypertension
-major factors include:
—weight gain
—sedentary life style

Question 4

What is secondary hypertension?

Answer 4

-hypertension second to another cause

Question 5

What are lethal effects of chronic hypertension?

Answer 5

• early heart failure and coronary artery disease
• cerebral infarct
• kidney failure

Question 6

What is atherosclerosis?

Answer 6

• hardening of the arteries

- caused by lesions in the intima of vessels walls which can protrude into the vessel lumen

Question 7

Increased arterial pressure leads to __________ and __________.

Answer 7

Increased urine output (pressure diuresis) and increased sodium output (pressure natriuresis)

Question 8

What are the risk factors of atherosclerosis?

Answer 8

Non-modifiable:

• age (40-60)
• gender (postmenopausal women)
• genetic

Modifiable:

• hyperlipidemia
• hypertension
• cigarette smoking
• diabetes

Question 9

What is an atheroma?

Answer 9

-cap of smooth muscle cells, macrophages, foam cells, and other extracellular components overlaying a necrotic center

Question 10

What are two ways by which the kidneys can increase blood pressure?

Answer 10

• decrease renal output (shift renal output curve to the right)
• increase renal intake (elevate renal intake curve)

Question 11

What is the difference between renal output curves for acute and chronic hypertension?

(L13 S32-33)

Answer 11

• chronic: increased salt intake causes small changes in arterial pressure
• acute: increased salt intake causes a greater change in arterial pressure

Question 12

What is chronic hypertension (including severe)?

Answer 12

-when mean arterial pressure is greater than the upper range of accepted normal

Normal:

• MAP: 90mmHg
• BP: 110/70

Hypertensive:

• MAP: 110 mmHg
• BP: >135/90

Severe hypertension:

• MAP: 150/170 mmHg
• BP: 250/130

Question 13

What are the lethal effects of chronic hypertension?

Answer 13

• early heart failure
• coronary heart failure
• heart attack
• cerebral infarct
• kidney failure

Question 14

What are the factors involved in the renin-angiotensin system and where are they secreted from?

Answer 14

• renin (kidney
• angiotensinogen (liver)
• angiotensin I
• angiotensin II
• ACE/angiotensin converting enzyme (endothelium)
• aldosterone (adrenal gland)
• ANP/atrial natriuretic peptide(atrium of heart)

Question 15

Describe the process of the renin-angiotensin system.

Slide 42

Answer 15

• decreased blood pressure causes the KIDNEY to release RENIN
• renin converts ANGIOTENSIONGEN (liver) to ANGIOTENSION I
• ACE (endothelium) converts angiotensin I to ANGIOTENSIN II
• angiotension II stimulates the ADRENAL GLAND to secrete ALDOSTERONE
• aldosterone causes the KIDNEY to increase sodium and water REABSORPTION
• angiotension II increases blood pressure causing atrium to release ANP which cause VASODILATION