The Adrenal Gland

Question 1

where are the adrenal glands situated

Answer 1

on the superior pole of the kidney in the retroperitoneal spacce

Question 2

where does the left adrenal vein drain into

Answer 2

left renal vein

Question 3

where does the right adrenal vein drain into

Answer 3

directly into the inferior vena cava

Question 4

what kind of tissue makes up the adrenal medulla

Answer 4

modified sympathetic ganglion derived from neural crest tissue

Question 5

what does the adrenal medulla secrete

Answer 5

catecholamines (epinephrine norepinephrine dopamine)

Question 6

what kind of tissue makes up the adrenal cortex

Answer 6

adrenal cortex is a true endocrine gland derived from mesoderm

Question 7

what are the 3 classes of steroid hormone that the adrenal cortex secretes

Answer 7

mineralcorticoids
glucocorticoids
sex steroids

Question 8

what does the zona glomerulosa secrete

Answer 8

aldosterone (mineralcorticoid)

Question 9

what does the zona fasiculata secrete

Answer 9

glucocorticoids

Question 10

what does the zona reticularis secrete

Answer 10

sex hormones

Question 11

what enzyme is needed to make aldosterone and cortisol

Answer 11

21-hydroxylase

Question 12

what are considered the 2 min products of the adrenal cortex

Answer 12

cortisol and aldosterone

Question 13

what is DHEA

Answer 13

a prehormone of testosterone and oestrogen

Question 14

what is a common cause of congenital adrenal hyperplasia

Answer 14

defects in 21 hydroxylase

Question 15

which hormone does cortisol have a negative feedback effect on

Answer 15

ACTH

Question 16

what percentage of plasma cortisol is bound to a carrier protein

Answer 16

95%

Question 17

what is the carrier protein that cortisol binds to

Answer 17

cortisol binding globulin

Question 18

what kind of cells have receptors for glucocorticoid

Answer 18

all nucleated cells have cytoplasmic receptors for glucocorticoid

Question 19

does cortisol or ACTH have longer half life

Answer 19

cortisol has a longer half life

Question 20

when do cortisol and ACTH peak

Answer 20

6-9am

lowest level midnight

Question 21

cortisol is essential to life why

Answer 21

1. maintains blood glucose levels
2. protects the brain from hypoglycaemia
3. has a permissive action on glucagon

Question 22

what is the actions of cortisol on glucose metabolism

Answer 22

1. gluconeogensis-stimulates the formation of gluconeogenic enzymes in the liver
2. proteolysis- to provide gluconeogenic substrates for the liver
3. lipolysis-which increases [FFA] plasma creating an alternative fuel supply that allows [BG] to be protected
4. decrease insulin sensitivity of tissues

Question 23

excess cortisol is said to be ________

Answer 23

diabetogenic as in acts to oppose insulin

Question 24

what effect does cortisol have on Ca2+ balance

Answer 24

decrease Ca2+ absorption from the gut

increases excreation at the kidney

increases bone resorption

Question 25

what effect does cortisol have on mood

Answer 25

hypercortisolaemia is associated with depression and impaired cognitive function

Question 26

what effect does cortisol have on epinephrine

Answer 26

permissive,

(particularly in vascular smooth muscle (alpha-receptor effect = vasoconstrictive therefore cushings disease is strongly associated with hypertension)

Question 27

what effect does cortisol have on the immune system

Answer 27

suppression (inhibits the inflammatory response too)

Question 28

what is the effect of increased aldosterone release

Answer 28

stimulates Na (and H2O) retention and K+ depletion at the kidneys

resulting in increased blood volume and pressure

Question 29

what is the effect of decreased aldosterone secretion

Answer 29

leads to Na (and H2O) loss and increased [K+] plasma

resulting in decreased blood volume and decreased blood pressure

Question 30

at which site in the kidneys does aldosterone act

Answer 30

acts on the distal tubule

Question 31

what is Cushing’s disease

Answer 31

hypersecretion of cortisol

Question 32

what are the most common causes of hypersecretion of cortisol

Answer 32

a tumour (adrenal cortex/pituitary)

iatrogenic

Question 33

what is addisons disease

Answer 33

hyposecretion of ALL adrenal steroids due to autoimmune destruction of the adrenal cortex

Question 34

what is a Pheochromocytoma

Answer 34

a rare neuroendocrine tumour, found in adrenal medulla which results in XS catecholamines

Question 35

why do you have to be careful when withdrawing chronic glucocorticoid treatment

Answer 35

there is a risk of adrenal insufficency if withdraw too fast

Question 36

what can be side effects of glucocorticoid therapy (increased cortisol)

Answer 36

1. increased severity of infection (as cortisol suppresses the immune system)
2. loss of percutaneous fat stores gives the appearance of thinning skin (as cortisol promotes lipolysis and protein catabolism)