15. Adrenal glands - functional assessment

Question 1

what is the morphology of the adrenal gland ?

Answer 1

located at top of kidneys

consist of two major component :
peripheral cortex (consist of 3 zones)
there central medulla

Question 2

what are the three zones in the adrenal cortex and what are their function ?

Answer 2

all these hormones produces are made from cholesterol = steroid hormones
there are INTRACELLULAR RECEPTORS FRO THEM
————-

Zona glomerulosa
: secretes mineralcorticoids (aldosterone mainly)
in response to stimulation by Angiotensin 2

Aldosterone then acts
increased Na2+ and thus increased water reabsorption
increased CL reabsorption
K+ excretion
H+ excretion
Na2+ and water reabsorption from the gut

Zona fasciculata:
secretes the glucocorticoids -cortisol mainly
in response to ACTH from pituitary gland

immunosuppesion - inhibits phospholipase 2
antagonist of insulin and increases peripheral insulin resistance = increase blood glucose by gluconeogenesis

zona reticularis: secretes androgens (mainly dehydroepiandosterone DHEA) and DHEA-Sulfat)

Question 3

side effects of cortisol therapy ?

Answer 3

risk of developing diabetes type 2

Question 4

what is the function adrenal medulla ?

Answer 4

preganglionic sympathetic fibres stimulate the secretion of epinephrine/ adrenaline into the blood stream

norepinephrine is the neurotransmitter

Question 5

describe the functional assessment of the adrenal gland ?

Answer 5

Blood cortisol - rise and fall through out day highest being in the morning
so not effective thing one sample
———–

Adrenocorticotropin hormone, or ACT from pituitary
adrenals not functioning = increase ACTH
———–

adrenal stimulation test
measure cortisol levels before and after stimulation of the adrenal glands
the
co
rtisol level is measured and then the patient is injected with a synthetic form of
ACTH called cosyntropin. After 45 minutes, the blood cortisol level is measured agai
failure of cortisol rise = adrenal dysfunction

corticotropin releasing hormone test
baseline levels of ACTH and cortisol are measure
corticotropinreleasing hormone chemical that stimulates the release of ACTH(not of cortisoldirectly!) is injected. Cortisol and ACTH levels are measured every 15 minutes.
Typically, ACTH levels peak after 15 to 30 minutes, and cortisol pevels peak 30 to 40

glucocorticoid function
8am fating and sleeping midnight cortisol sample
or 24 urine collection

androgen test
standard syncathen test = measure basal ACTH and steroid precursors 17 hydroxyprogesterone
and DHAS - dehydroepiandrosterone sulphase
and androstenedione
before and after 60 min of stimulation