Aldosterone

Question 1

Adrenal cortex is organized into 3 distinct zones

Answer 1

1. zona glomerulosa
2. Zona fasciculata
3. zona reticularis

Question 2

Importance of Aldosterone

Answer 2

essential to sodium retention
in 3 primary tissues: principal cells (kidney, large intestine, sweat glands)

Question 3

2 types of salt retention by the kidney

Answer 3

regulated + non-regulated (countercurrent system»_space; osmotic gradient)

Question 4

major site of mineralocorticoid activity

Answer 4

Kidney

Question 5

What happens when aldosterone binds to the mineralocorticoid receptor (MR) in target cell?

Answer 5

affects transcriptional changes (typical of steroid hormone action)

Question 6

What retains Na+ and H2O in the body

Answer 6

aldosterone stimulates Na+ reabsorption in the collecting ducts

Question 7

what does Aldosterone cause in the kidney

Answer 7

increase blood pressure by increasing extracellular fluid volume
increase urine excretion of K+ and H+

Question 8

main function of aldosterone is to

Answer 8

sustain extracellular fluid volume by conserving body sodium

Question 9

when body sodium is depleted

Answer 9

the fall in extracellular fluid and plasma volume decreases renal arterial blood flow and pressure (activating RAA system)

Question 10

Aldosterone is largely secreted in response to

Answer 10

signals that arise from the kidney when a reduction in circulating fluid volume is sensed

Question 11

Aldosterone facilitates ….

Answer 11

clearance of potassium from the extracellular fluid

Question 12

potassium stimulates

Answer 12

aldosterone synthesis
- providing feedback control mechanism to control potassium levels

Question 13

potassium depletion

Answer 13

reduced aldosterone secretion

Question 14

stimulation of aldosterone synthesis by potassium

Answer 14

depolarization of zona glomerulosa cell membrane
- causing Ca+2 voltage changes to increase in intracellular Ca 2+ stimulates expression of P450aldo

Question 15

regulation of aldosterone

Answer 15

+
Potassium (main)
Angiotensin 2 (main)
ACTH (not so much)

-
ANP (atrial natriuretic peptide

Question 16

RAA

Answer 16

Renin- Angiotensin - Aldosterone system

Question 17

Granular juxtaglomerular cells are going to feel

Answer 17

Blood pressure

Question 18

Macula Densa sense

Answer 18

Sodium levels

Question 19

What stimulates the release of renin

Answer 19

Low blood pressure and low sodium levels

Question 20

Renin is produced in

Answer 20

juxtaglomerular cells

Question 21

Enzyme made by the liver

Answer 21

angiotensinogen

Question 22

What makes Angiotensin 1

Answer 22

conversion btw Angiotensinogen and renin

Question 23

What makes Angiotensin 2

Answer 23

Angiotensin 1 with ACE (angiotensin converting enzyme)

Question 24

Angiotensin 2 is potent in controlling

Answer 24

• increasing blood pressure
• stimulating NEP by neurons $ adrenal medulla
• reabsorption of K+
• also helps also aldosterone secretion
• AVP to help with H2O absorption
• water absorption

Question 25

angiotensin 3

Answer 25

potent pressor hormone controls aldosterone

Question 26

how to get angiotensin 2 to 3

Answer 26

amino peptidase A

Question 27

Angiotensin 2 &3 effects

Answer 27

increase - aldosterone synthesis and secretion - vasoconstriction - release of AVP - release of adrenal catecholamines - central sympathetic outflow

Question 28

Angiotensin 2 goal

Answer 28

maintain normal extracellular volume and blood

Question 29

increasing transcription of P450aldo

Answer 29

increases aldosterone production

Question 30

increasing vasoconstriction

Answer 30

increase blood pressure and renal blood flow (decrease renin)

Question 31

Release EPI and NEP from

Answer 31

adrenal medulla

Question 32

angiotensin 2 enhance activity of the

Answer 32

sympathetic nervous system and NE release in nerve terminals

Question 33

promote release of AVP

Answer 33

increase water reabsorption in collecting ducts

Question 34

Angiotensin 2 receptors

Answer 34

AT1 & AT2

Question 35

AT1

Answer 35

- adrenal, cardiovascular, renal effects - Gq >> Ca+2 to elicit response

Question 36

AT2

Answer 36

associated with effects NOT related with aldosterone

Question 37

Regulation of aldosterone (if you have tooo much)

Answer 37

Atrial natriuretic Peptide (ANP)

Question 38

as a result of volume expansion , atrial myocytes secrete

Answer 38

ANP >> binds to receptors in the zona G. to inhibit aldosterone synthesis

Question 39

ANP counterbalance the effect of

Answer 39

RAA on aldosterone secretion - ANP acts by increasing cGMP (opposes cAMP & inhibits aldosterone) - ANP also reduces aldosterone indirectly by inhibiting renin release