9 Aldosterone

Question 1

main direct effects of aldosterone?

Answer 1

• recovery of sodium in the kidney and enhanced potassium secretion into the urine
• regulates blood volume

Question 2

what 3 physical attributes of plasma can be regulated to affect the homeostasis of the blood system?

Answer 2

• volume
• blood pressure
• osmolarity

Question 3

what comes first: thirst of sodium appetite?

Answer 3

thirst

Question 4

what kind of cells control the ability of blood vessels to constrict/dilate?

Answer 4

smooth muscles around the vessels

Question 5

what hormones control how much aldosterone is in the system?

Answer 5

• renin

- angiotensin

Question 6

where is renin produced?

Answer 6

kidney

Question 7

what is angiotensinogen?

Answer 7

produced by the liver; it’s the inactive form of angiotensin I; activated by interacting with renin

Question 8

how is angiotensin I converted angiotensin II?

Answer 8

enzyme from the lungs called ACE acts on angiotensin I

Question 9

relationship between angiotensin II and aldosterone?

Answer 9

angiotensin II stimulates aldosterone secretion

Question 10

true or false ACTH has tight regulator function with regard to aldosterone

Answer 10

false - it’s a modest effect

Question 11

effect of angiotensin II?

Answer 11

• increases Na absorption and K excretion

- water retention, higher blood pressure

Question 12

what’s the speculated use of angiotensin II in the brain?

Answer 12

functions as a local regulator playing a role in thirst behavior

Question 13

what cells recognize Na levels in the kidney tubule?

Answer 13

Macula densa

Question 14

from angiotensin II, how is it degraded?

Answer 14

converted to angiotensin II by aminopeptidase and then converted to degradation products

Question 15

when macula densa cells recognize lower sodium concentration, this does what pertaining to the release of renin?

Answer 15

upregulates

Question 16

immediate effects of angiotensin II?

Answer 16

• acts directly on the blood vessels inducing vasoconstriction

Question 17

slow angiotensin II effects?

Answer 17

affects sodium reabsorption

Question 18

longer term angiotensin II effects?

Answer 18

regulation of wall tension

Question 19

how does aldosterone function?

Answer 19

gene expression

sodium is reabsorbed, potassium is being pushed out, water follows it back in (slide 11)

Question 20

what channels are on the luminal side?

Answer 20

• Sodium ENaC channels - these are the ones affected by aldosterone
• aquaporins (slide 10)

Question 21

what channels are on the basal side?

Answer 21

Sodium K-ATPase - this one balances the effect of aldosterone onto the ENaC (slide 10)

Question 22

where does aldosterone mainly work?

Answer 22

distal tubules & collecting ducts of the kidney

Question 23

what happens when you have too much aldosterone?

Answer 23

Conn’s syndrome - increases blood pressure (excess sodium retention)
- serum alkalosis and neuropathy (excess K+ and H + excretion)

Question 24

what causes Conn’s syndrome

Answer 24

either adrenal hyperplasia or tumors

Question 25

where are natriuretic peptides secreted?

Answer 25

cardiac muscle

Question 26

what do natriuretic peptides do?

Answer 26

control sodium release by kidney; reduce blood volume and pressure

Question 27

what other hormone(s) can the adrenal cortex make?

Answer 27

sex steroids

Question 28

what is adrenarche?

Answer 28

earlier than usual maturation of adrenal glands as a result of sex steroid syntehsis

Question 29

expand CAH

Answer 29

congenital adrenal hyperplasia

Question 30

what is CAH?

Answer 30

- excessive androgen production | - masculinization of genitalia

Question 31

go look at slide 16

Answer 31

:)

Question 32

what happens with a CAH female

Answer 32

- ovary forms because of absence of Y chromosome - large adrenal glands produces sex hormones that can lead to DHT which can lead to the masculinization of external genitalia

Question 33

what happens when you have a deficiency in 21 hydroxylase enzyme?

Answer 33

- low cortisol (less negative effect on pituitary, less ACTH produced) - low aldosterone - more tropic signals coming to the adrenal gland

Question 34

how is CAH treated?

Answer 34

surgery at birth

Question 35

which nervous system is the adrenal medulla involved in?

Answer 35

sympathetic

Question 36

what response does the adrenal medulla elicit?

Answer 36

fight/flight; increases blood pressure and cardiac output, dilate pupils

Question 37

what catecholamines are produced in the adrenal medulla?

Answer 37

- norepinephrine | - epinephrine

Question 38

what pathways inactivate norepinephrine and epinephrine?

Answer 38

Comt and Mao

Question 39

what are met-enkephalin and leu-enkephalin?

Answer 39

related to endorphins; associated with runner's high

Question 40

acute fight/flight response?

Answer 40

integrates lots of organ systems to efficiently provide response

Question 41

what organ systems get "neglected" during the fight or flight response?

Answer 41

skin, GI

Question 42

function of epinephrine/norepinephrine?

Answer 42

- increase muscle glycogenolysis - increase glucose levels in the brain - reduces insulin concentration, which reduces uptake by other cells except the brain - increases cardiac output - increases blood pressure/blood flow

Question 43

what kind of receptors are the adrenergic receptors?

Answer 43

GPCRs

Question 44

what is salbutamol?

Answer 44

B2 inhibitor; used to treat asthmatic symptoms

Question 45

difference between epinephrine and norepinephrine?

Answer 45

epi - more robust in terms of cardiac stimulation and metabolic effects nor - more robust in blood vessel constriction

Question 46

true or false: anything that affects the adrenal cortex can also affect the adrenal medulla

Answer 46

yeah, because cortisol has an effect on catecholamines as well

Question 47

what happens when you have hyper-secretions of catecholamines?

Answer 47

``` - caused by tumors causes general symptoms - headache - hypertension - sweating - palpitations - chest pain - anxiety - glucose intolerance - increased metabolic rate (similar effects to anxiety) ```