adrenal gland physiology Flashcards
functions of cortisol
T/F is cortisol catabolic
T
what are the main uses of corticosteroids
suppress inflammation
suppress immune system
replacement treatment
what receptor does aldosterone act on
mineralocorticoid receptor >
these receptors can be found on: kidneys , salivary glands , gut and sweat glands
effects of aldosterone
sodium / potassium balance
blood pressure regulation
regulation of extracellular volume
what is Addisons
adrenal/cortisol deficiency
adrenal glands aren’t working = primary insufficiency , what are some examples
addisons
congenital adrenal hyperplasia
adrenal TB/malignancy
secondary insufficiency = pituitary gland not working eg …
due to lack of ACTH - stimulation - exogenous steroid use is the commonest cause
iatrogenic
pituitary / hypothalamic disorders
tertiary causes of adrenal insufficiency
to do with hypothalamus
most commonly drug induced
steroid use over a long time
tertiary causes of adrenal insufficiency
to do with hypothalamus
most commonly drug induced
steroid use over a long time
symptoms of addisons
anorexia
wt loss
dizziness and low BP
abdominal pain, vomitting, diarrhoea
skin pigmentation
causes of addisons
autoimmune destruction of adrenal cortex due to autoantibodies targeting those cells
associated with T1DM, autoimmune thyroid disease, and B12 deficiency
diagnosis of addisons
SYNACTHEN test - the main one
management of adrenal insufficiency
do not delay
hydrocortisone as cortisol replacement :
if unwell give IV first, 200mg with IV fluids
if they’re ok :
oral hydrocortisone and try to give them it throughout the day
fludrocortisone as aldosterone replacement - careful monitoring of BP and K
educate the patients
what to do in an adrenal crisis
0.9NaCl (saline)
100mg IV hydrocortisone
treat underlying cause
…if in doubt always better to over treat
investigations for cushings order
screening > low dexamethasone test > check ACTH levels
hypokalaemia + hypertension =
primary aldosteronism: autonomous production of aldosterone independent of its regulators
what regulates aldosterone
angiotensin II/ potassium
what are the cv actions of aldosterone
clinical features of PA
significant hypertension
hypokalaemia
alkalosis
subtypes of PA
adrenal adenoma - Conn’s
bilateral adrenal hyperplasia
rare causes = unilateral hyperplasia, genetics
subtypes of PA
adrenal adenoma - Conn’s
bilateral adrenal hyperplasia
rare causes = unilateral hyperplasia, genetics
diagnosis of PA
management of PA
surgery : unilateral laparoscopic adrenalectomy only if there is an adrenal adenoma
>cures hypokalaemia and hypertension
medical : MR antagonists ie spironolactone or eplerenone
in bilateral adrenal hyperplasia
what is this
left adrenal adenoma
what are congenital adrenal hyperplasia syndromes
an inherited group of disorders characterised by a deficiency in one of the enzymes necessary fro cortisol synthesis
commonest is 21a hydroxylase deficiency
variants of 21a hydroxylase deficiency
classically = salt-wasting, simple virilising
non-classical = hyperandrogenaemia
presentation of CAH in males
adrenal insufficiency
poor weight gain
biochemical patten
presentation of CAH in females
genital ambiguity
non-classical presentation of CAH
hirsute
acne
oligomenorrhoea
precocious puberty
infertility/subfertility
tx of CAH in children
timely recognition
glucocorticoid replacement
mineralcorticoid replacement
surgical correction
tx of CAH for adults
control androgen excess
restore fertility
avoid steroid over replacement
