Long Term Control of Blood Pressure

Question 1

Long term control of blood pressure is probably not mediated by

Answer 1

the arterial baroreflex

Question 2

Long term control of blood pressure revolves around the control of

Answer 2

plasma volume by the kidney

Question 3

Long term control involves what three distinct hormone systems?

Answer 3

• Renin-angiotensin-aldosterone system
• Antidiuretic factor
• Atrial natriuretic peptide

Question 4

Give 3 functions of the kidneys

Answer 4

• excretion of waste products
• maintenance of ion balance
• regulation of pH
• regulation of osmolarity
• regulation of plasma volume

Question 5

What system creates a very high osmolarity outside the collecting duct of the kidney?

Answer 5

Renal counter-current system

Question 6

What determines how big the osmotic gradient between the outside and inside of the collecting duct is?

Answer 6

Na+ transport

Question 7

What will determine whether water follows the osmotic gradient between the inside and outside of the collecting duct?

Answer 7

Permeability of the collecting duct to water

Question 8

Making the collecting duct very permeable to water will result in

Answer 8

• lots of water reabsorption

- little urine

Question 9

Making the collecting duct very permeable to water will conserve

Answer 9

plasma volume

Question 10

If the collecting duct is very permeable will it result in a small volume or hypo or hyper-osmotic urine?

Answer 10

Hyper-osmotic

Question 11

If the collecting duct is very impermeable will it result in a large volume of hypo or hyper-osmotic urine?

Answer 11

Hypo-osmotic

Question 12

From what part of the kidney is renin produced?

Answer 12

Juxtaglomerular

Question 13

What 3 things trigger renin production?

Answer 13

• activation of sympathetic nerves to juxtaglomerular apparatus
• decreased distension of afferent arterioles
• decreased delivery of Na+/Cl- through the tubule

Question 14

Renin production being triggered is a sign of low

Answer 14

mean arterial pressure (MAP)

Question 15

Renin converts inactive angiotensinogen to

Answer 15

angiotensin I

Question 16

Angiotensin I is converted by angiotensin converting enzyme to

Answer 16

angiotensin II

Question 17

Give three functions of angiotensin II

Answer 17

• stimulates release of aldosterone from the adrenal cortex
• increases release of ADH from pituitary
• vasoconstrictor

Question 18

Give two effects of aldosterone released from the adrenal gland

Answer 18

• increases Na+ reabsorption in the loop of Henle

- reduces diuresis and increases plasma volume

Question 19

Give two effects of ADH released from the pituitary

Answer 19

• increases water permeability of collecting duct
• reduces diuresis and increases plasma volume
• increases sense of thirst

Question 20

What kind of system is the renin-angiotensin-aldosterone system?

Answer 20

Negative feedback system

Question 21

What tends to be increased by the renin-angiotensin-aldosterone system?

Answer 21

Mean arterial pressure

Question 22

Where is ADH synthesised?

Answer 22

Hypothalamus

Question 23

Where is ADH released from?

Answer 23

Posterior pituitary

Question 24

Give 3 sings of low MAP that trigger ADH release

Answer 24

• decrease in blood volume
• increase in osmolarity of interstitial fluid
• circulating angiotensin II

Question 25

What type of system is the antidiuretic hormone system?

Answer 25

Negative feedback system

Question 26

Where is atrial natriuretic peptide produced and released from?

Answer 26

Myocardial cells in the atria

Question 27

What triggers ANP release?

Answer 27

Increased distension of the atrium

Question 28

Give 3 functions of ANP

Answer 28

• increases excretion of Na+
• inhibits release of renin
• acts on medullary cardiovascular centres to reduce MAP

Question 29

Give two rational drug treatments based on hormones acting on the kidney

Answer 29

• Ca2+ channel antagonists
• Beta-adrenoceptor antagonists
• thiazide diuretics
• angiotensin converting enzyme inhibitors