Adrenal Gland

Question 1

What is the inactive form of cortisol?

Answer 1

cortisone that prevents long-acting of cortisol

also increases solubility so excreted by kidneys

Question 2

What is the rate-limiting enzyme in steroidogenesis?

Answer 2

StAR = shuttle cholesterol from storage cells or cytoplasm to mitochondria

Question 3

What are the 2 important enzymes in steroidogenesis?

Answer 3

StAR and p450scc (side chain cleavase)

Question 4

What are the main functions of cortisol?

Answer 4

• glycogen synthesis in liver
• gluconeogenesis = lipolysis and protein catabolism from muscles
• increase blood glu
• anti-inflammatory

Question 5

What are the consequences of long cortisol effect?

Answer 5

• GI tract ulcerations
• depression + psychosis
• skin thinning + muscle wasting
• impact on vertical growth
• more risk of infections
• osteoporosis
• hypertension from hypervolemia => aldosterone like acting

Question 6

What is the enzyme responsible for the conversion of cortisol to its inactive form?

Answer 6

Type 2 11B HSD

Question 7

What is AME?

Answer 7

enzyme deficiency of HSD11B2

Question 8

How cortisol is transported?

Answer 8

corticosteroid binding globulin (CBG = transcortin) produced in liver
also regulates availability

Question 9

How cortisol is transported?

Answer 9

corticosteroid binding globulin (CBG = transcortin) produced in liver
also regulates availability = protected from inactivation

Question 10

What syndrome is characterized by an overproduction of cortisol?

Answer 10

Cushing’s disease (ACTH dependent or independent = adrenal gland tumor that produces cortisol)

Question 11

What are the possible causes of an overproduction of cortisol?

Answer 11

• CRH producing tumor
• ACTH producing tumor
• adrenal gland tumor
• lack of -ve feedback
• latrogenic cause from steroid treatment = need close monitoring

Question 12

What is the effect of Addison’s disease on the brain?

Answer 12

low cortisol = defects in liver = low glucose levels in blood = brain coma and death
low aldosterone = low blood pressure = shock

Question 13

What is the function of aldosterone?

Answer 13

Recovery of Na+ in kidneys and K+ secretion in urine = adjustment of ECF + blood volume

Question 14

What are the roles of Angiotensin II?

Answer 14

• Na absorption and K excretion (+ water)
• vasoconstriction
• AVP stimulation

Question 15

What does stimulate renin production?

Answer 15

decrease in renal arterial flow sensed by baroreceptors of macula densa

Question 16

what are the acute effects of angiotensin II?

Answer 16

direct vasoconstrirction
adrenal medullary catecholamines secretion
sympathetic discharge

Question 17

How does aldosterone acts on Na+ reabsorption?

Answer 17

=> aldosterone binds to its receptor inside the cell
=> alters DNA transcription to make structural proteins (transporters) and regulatory proteins (kinases)
=> Na uptake by ENaC
=> increase activity of Na,K ATPase

Question 18

what are natriuretic peptides?

Answer 18

secreted by cardiac muscles
play a role in Na transport = release of sodium in
reduce renin secretion

Question 19

What is Conn’s syndrome?

Answer 19

hypersecretion of aldosterone
=> excess secretion of K and H => serum alkalosis + hypocalcemia
=> increase H2O retention

Question 20

What are catecholamines and how are they synthesize?

Answer 20

• epinephrine and norepinephrine (adrenaline and noradrelanine)
• synthesized from tyrosine => dopa (rate limiting step) => dopamine => epinephrine => norepinephrine

Question 21

What are the consequences of early secretion of sex steroids (testosterone)?

Answer 21

growth spurts and adrenarche = body hair growth in females

Question 22

What enzymes are responsible for the inactivation of catecholamines?

Answer 22

MAO + COMT

Question 23

what is the enzyme that converts epinephrine in norepinephrine?

Answer 23

PNMT

Question 24

What are the hormones secreted by adrenal medulla?

Answer 24

• catecholamines

- met-enkephalin

Question 25

What are the hormones secreted by adrenal medulla?

Answer 25

- catecholamines | - met-enkephalin (related to endorphins)

Question 26

What the types of adrenergic receptors?

Answer 26

GPCR | alpha-1, beta-1 and 2

Question 27

What is the role of epinephrine?

Answer 27

mobilize FAs for muscle action increases glucogenolysis glucose for brain = decreasing insulin increase cardiac output

Question 28

What is the role of norepineprine?

Answer 28

increase blood flow and decrease insulin secretion

Question 29

Draw the adrenal medulla with its signals recieved and sent

Answer 29

GO

Question 30

Why does angiotengin II increase growth factors as a slower response?

Answer 30

for vascular and cardiac hypertrophy and remodeling = greater cardiac output = increase blood pressure

Question 31

What is pheochromocytoma?

Answer 31

tumor that overproduces catecholamines

Question 32

Where are present adrenergic receptors?

Answer 32

``` a1 = smooth muscles (skin + GI) + nerve terminal B1 = heart, cerebral cortex B2 = lungs, smooth muscle, cerebellum ```

Question 33

On what epinephrine has a bigger impact?

Answer 33

metabolism + cardiac output