Adrenal Disorders Flashcards
adrenal gland parts and their function
outer = cortex (most outer layer to inner)
- zona glomerulosa ; mineralocorticoids (aldosterone) NA+ and K+ levels
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zona fasciculata ; glucocorticoids ( cortsiol and corticosterone metabolism of carbohydrates
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zona reticularis ; androgens sex hormone
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zona reticularis ; androgens sex hormone
inner = medulla
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adrenaline
- noradrenaline
disorders of the adrenal cortex
too much hormones of the adrenal corex or too little
- adrenal insufficiency
- congenital adrenal hyperplasia
- hyperaldosteronism
disorders of the adrenal medulla
pheochromocytoma and paraganglioma
clinical presentation of adrenal hormone deficiency
-autoimmune infiltration of immune cells -addisons disease ; v in
what hormones are decreased in adrenal deficiency
cortisol , androgens , mineralocorticoid
why is androgen deficiency worse in women
because its the only source of androgen
cortisol def.
- tired, lethargy , low blood sugar since its anti -insulin -treatment is tablets
aldosterone def.
- dizziness, since lose water, too much potassium
androgen def.
- loss of hair and axillae, and v libido
too much cortisol
- cushings syndrome
too much aldosterone
- high blood pressure and low potassium
excess ACTH
- d low cortisol
adrenal medulla dsiease
palpitations,, ^/vbp, anzixety
assessment for adrenal cortex diseases
- blood tests basal cortisol test 0900 - stimulation test ; give ACTH
stimulation test vs supressio test
- give ACTH
supress
- electrolytes -cortisol midnight - 24hours urine cortisol
how to test the adrenal medulla
- 24 urine catechol - 24 urine metanephrines (break down components of ad/nad) - plasma metanephrine (more sensitive than urine) - tell patients to not have coffee, chocolate, vanilla
imaging of adrenal diseases
-CT -MRI -functional imaging -PET -MBG
Addisons disease
-primary adrenal failure -skin pigmentation., vitiligo, pig. accentuation of the nipples , freckling , darkening of hair, underweight , thyroid problems , low bp when stand up, nausea -c autoimmune isolated or polyglandular, -infection (TB< FUNGAL< AIDS -infiltration , amyloid, -malignancy lung, breast, -T = lifelong meds of gluocortisol , mineralocorticoid
adrenal crisis
- § ; collapse, hypotension, dehydration, pigmentation, coma - treatment is rehydration and cortisol
long term steroids c
- ACTH deficiency - so can get adrenal rises
steroids
-asthma, eczema , herbal treatments
adrenal cushings
- pitu tumour - §; hirsutism , acne, greasy skin - large tumours ; androgenic shock,
young patient, on tablets hypertension
hyperadosteroism
CAH
-autosomal recessive, but marrying cousins you get autosomal homozygous - blooming of an enzyme -lack of cortisol and aldosterone but really high androgen so with baby girl you get them looking like boys
phaechromocytome
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paraganglioma
outside the adrenal cortex -can c sudden death - management ; a and b blockage
histology of pphaechromocytoma
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embryology of the adrenal cortex
during development he cortex is derived from mesoderm, whereas the medulla is derived from the neural crestcells wc migrae to the developing cortex
how does aldosterone work
it controles the rate at which NA”+ are reabsorbed or excreted, and it useds the NA/K+ pump.
since sodium is osmotticaly actie it plays a role in water control and so BP
t affects the expresionof basolateral NA/K+ pump,more expressed more NA+ reabosrbed (but also theres a risk of losing too much K+ and becoming hypokalemic)
it also affects the expression of epithelial sodium channel ENaCs on the collecting duct and so more na+ reabsorption
it is also part of the RAAS system
whats the function and structure cortisol
its a a member of the c12 steroid family, and since its a steroid hormone its lipophilic and synthesised from cholesterol
enters cells and bind to cytoplasmic receptros forming hormone-receptor complex then enters the nucleus and interacts with specific regionsof DNA affecting the rate fo trasncription of specific genes
it causes things like ;
- v rate of amino acid uptake
- v protein syntehsis
- ^hepatic gluconeogenesis and glycogenolysis
- ^lipolysis in adipose tissue
- peripheral uptake of glucose
secretion is controlled by ACTH
os it lipophilic and so is transorted bond to plasma proteins, the main transporter being transcortin 90% , the rest 10% is transported on albumin
describe whats in the adrenal medulla and how its synthesised
chromaffin cells convert amino acid tyrosine into dopamine, then dopamine is converted into adrenaline
funcitons of adrenaline are
^ CVS
^ mental alertness
^ glycogenolysis in liver and muscel
^lipolysis
adrenaline binds to GCPR a and beta
excess cortisl secretion
cortisol fucntion is to ^liplysis/^glycogenolysis and gluconeogenesis/vproteinsynthesis/vaminoacid upatake/vglucose uptake(anti-insulin)
hypoeractivity of adreanl cortex can cause Cushing’s syndrome;
symptoms =
- steroid diabetes = ^ proteolysis, ^glyco.. c can cause hyperglycaemia associated with polyuria and polydipsia s steroid diabetes
- lipogenesis so deposition of fat in the abdomen, neck and face giving moon-shped face an weigth gain
- purple striae in the lower abdomen, upper arms and thighs due to the protein lysis c easy brusing as a result of the thinning of skin and subcutaneous tissue
- immunosupressive, anti=inflammtomry, anti-allergic reactions can cause ^ bacterial infections and acne
- pain and collapse of ribs due to osteoporosis caused. by distrubance of calciummetabolism and loss of bone matrix
- too much cortisol can cause aldosterone secretion so you get fluid retneion issues and hypertension
- pain and collapse of ribs due to osteoporosis caused. by distrubance of calciummetabolism and loss of bone matrix
causes of excess cortisol
increased acrivity of adrenal cortex due to primary cortisol producing adrenal adenoma
ACTH secretion disorders due to pituatiary adenome like in cushings disease
ectopic secretions of ACTH from small cell tumours of the lungs
cushings disease vs syndrome and which is more common
disease = pituitary adenoma
syndrome = symptoms due to excess cortsiol
syndrome
too little cortsil
due to decreased aactivity in the adrenal cortex - addisons disease
its due to autoimmune destructionof the adrenal cortec but you also find reduced glucocorticoids and meralcorticoids
disorder of the piut/hypo that causes v ACTH or CRF adn this affects only glucocorticoids
addisons disease vs crisis
cris = autoimmune destrution that involves loss of mineralcortiocid and corisol wc presents as an actue emergency
disease = chronic debilitating disorder
how do patients in addison’s disease / crisis present?
what makes it worse
disease ;
- tired, fatugues,
- vague abdominal pain
- weightloss,
- dizzinesss
- extreme muscular weakness and dehydration
- increased sin pigmentaion (especiallyin areas of friction, buccal mucosa, scars, palmar creass) this is due ot increased POMC(alpha MSh and gamma MSh wc stimulate melaocytes to produce more melanin
- decreased blood pressure d sodium depletion anfluid
- postural hypotension due to depletion
- hypoglycaemic epsiodes on fasting due to lack of glucocorticoid
made worse by stress, trauma,severe infetion,
how do you treat addison crisis
Ivfluids because tehir fluid is very low and IV cortisol to avoid death
qhats the most common causeof cushings syndrome
prescribed glucocorticoids (sterid hormones) anti-infamm drugs
clinical tests for adrenocorticlal function
- measure plasma cortisol adn ACTH levels
- 24 hours urinary excretion of cortisol and break down products (17-hydroxysteroids)
- dynamic functioning test = dexamethasone (suspresses ACTH and so cortsiol
how do you test for addison’s disease
give synacthen intramuscularly and it increases the plsma cortisol by >200nmol/L
this wouldn’t happen to someone with addison’s disease
what tests do you to differentiate betweent eh different causes of ^ b cortisol levels without imaging
- cushing’s disease = dexamethasone , inhibits ACTH release and so cortsiol levels should go down to normal
- due to adrenalcortex overfunctioning; then mineralcorticoids are also high adn so check aldosterone levels
- if you give dexamethasone and the ACTH levels are still high then its due tot cancer secreteing tumour thats secreting ACTh
congential adrenal hyperplasia
- theres a genetic defect an enzyme in the biosytnehitic pathway to make cortisol and so ^^ACTH due to negative feedback to try and increase cortisol levels, but cortisol cant be made well and so there’s adrenal hyperplasia
- most common genetic defect in the 21-hyroxylase enzyme means that the the biosynthesis of corticosteriuds from cholesterol doesnt occur as per usual so in return the precursor 21-hydroxypregnenolone is used in androgen synthesis (+testersone), thsi results in salt water rising (^^ NA+ in pee due to v aldosterone ) and female gential amiguity
what are the clinical presentation of people with congential adrenal hyperplasia
salt water rising due ot low aldosterone
female genitalia ambiguiity
whats conn’s disease
hyperaldosteronism
it can be unilateral or bilateral malfunctioning of the adrenal glands, uni = adenoma, bi= hyperaldodersternism type 1 or 2 genetic disease
symptoms of conn’s disease
high blood pressure , , occasional muscle weakness and spasm, tingling sesnsation an dexcessive urination
due to the potassium levels being so low hypokalcemia
how do you diagnose conn’s without imaging
decreasing renin will usually decrease aldosterone in normal people but people with conn’s syndrome the aldoserone levels dont decrease with low renin
whats the structure of a steroid receptor homology
nuclear hormones (so are thyroid and VD)
cortisol can bind to mineralcorticoid and adnrogens receptors when conc is really high
excess androgen in women
- congenital adrenal hyperplasia female genitalia ambiguity
- hirsutism (excessive hair growth)
- testerone ^
- deeper voice
- menstrural issues
- increased muscle bulk
whats the difference between type 1 and type 2 hyperaldosteronism
type 1
- due to adenoma of the adrenal cortex = conn’s syndrome
- bilateral idiopathic adrenal hyperplasia
- low rein:aldo
type 2
- due to overactive RAAS system
- d renal artery stenosis or renin producing tumour (rarely)like juxtaglomerular tumour
