Adrenal gland Flashcards by Jamie Craig

what is produced in the zona glomerulosa

mineralocorticoids

How well did you know this?

Not at all

Perfectly

what is produced in the zona fasiculata

glucocorticoids

How well did you know this?

Not at all

Perfectly

what is produced in the zona reticularis

androgens

How well did you know this?

Not at all

Perfectly

what cells are present in the adrenal medulla and what do they secrete

chromaffin cells

catecholamines

How well did you know this?

Not at all

Perfectly

describe how cholesterol becomes testosterone

synthesised to aldosterone, cortisol or DHEA/androstenedione, converted to testosterone
this is done by many individual enzymes

How well did you know this?

Not at all

Perfectly

regulation of cortisol and androgen synthesis?

hypothalamus recieves stress, time of day, illness to release CRH to ant pituitary
releases ACTH to cause cortisol production in adrenal
-ve feedback of cortisol on hypothalamus and ant pituitary

How well did you know this?

Not at all

Perfectly

describe the peak of cortisol

diurnal variation

highest at 6-10am and drops over the day before it is near zero at night

How well did you know this?

Not at all

Perfectly

describe regulation of aldosterone synthesis?

decreased BP leads to renin activation, angiotensinogen to ATI, converted to ATII by ACE, causes direct vasoconstriction and aldosterone to increase Na retention in kidneys to decrease fluid output

How well did you know this?

Not at all

Perfectly

6 classes of steroid receptor

glucocorticoid
mineralocorticoid 
vitamin D 
androgen 
oestrogen 
progestin

How well did you know this?

Not at all

Perfectly

effects of cortisol

increases blood sugar, lipolysis and proteolysis
decreases cytokines, macrophage activity, leucocyte migration
accelerated osteoporosis
decreased libido
euphoria/psychosis
increased BP, CO, renal blood flow and GFR

How well did you know this?

Not at all

Perfectly

what target tissues does aldosterone act on

kidneys
salivary glands
sweat glands
gut

How well did you know this?

Not at all

Perfectly

causes of primary adrenal insufficiency

addisons disease 
congenital adrenal hyperplasia 
TB/malignancy 
bilateral adrenal haemorrhage 
bilateral adrenalectomy 
drug induced by rifampicin, phenobarbital, anticoagulants

How well did you know this?

Not at all

Perfectly

causes of secondary adrenal insufficiency

lack of ACTH stimulation 
sheehans syndrome 
iatrogenic 
pituitary/hypothalamic disorders 
pituitary surgery/haemorrhage 
infection, trauma, tumour of pituitary/hypothalamus 
cushings disease/syndrome 
long term glucocorticoid therapy

How well did you know this?

Not at all

Perfectly

clinical features of addisons disease

anorexia 
weight loss 
skin pigmentation 
abdominal pain and vomiting 
diarrhoea
fatigue 
lethargy

How well did you know this?

Not at all

Perfectly

what is addisons disease

autoimmiune destruction of the adrenal cortex

How well did you know this?

Not at all

Perfectly

what other AA conditions is addisons disease associated with

pernicious anaemia, T1DM, AA thyroid disease

How well did you know this?

Not at all

Perfectly

biochemical diagnosis of addisons disease

hyponatraemia and hyperkalaemia 
hypoglycaemia 
SST - normal is >250 and post ACTH >550nmol/L
high ACTH
renin high and aldosterone low

How well did you know this?

Not at all

Perfectly

what test is diagnostic to addisons disease

21-OH-Ab is indicative if pt is over 6m

if -ve get CT adrenals for infiltrative disease, malignancy, infection, haemorrhage

How well did you know this?

Not at all

Perfectly

management of addisons disease

hydrocortisone - IV if unwell and then oral in divided doses
flurocortisone as aldosterone replacement and monitor BP and K
steroid card
sick day rules
cannot stop suddenly

How well did you know this?

Not at all

Perfectly

management of adrenal crisis

fluids
100mg hydrocortisone 
hydrocortisone infusion or 6hr IM 
cardiac monitor 
treat cause

true/false - there is a need to treat aldosterone in secondary adrenal insufficiency

false - aldosterone is managed by RAAS

ACTH dependent causes cushings syndrome

pituitary adenoma
Ectopic ACTH
ectopic CRH

ACTH indepedent causes of cushings syndrome

Adrenal adenoma/carcinoma

adrenal hyperplasia

clinical features cushings syndrome

easy bruising 
thin skin 
striae 
proiximal myopathy 
interscapular fat pad 
euphoria/altered mood/psychosis 
thin arms/legs 
increased abdo fat 
cataracts 
osteoporosis 
menstrual irregularity 
hypertension
oedema 
decreased libido
hirsutism 
acne 
virilism

diagnosis of cushings syndrome

overnight dexamethasone suppression test 24 hr urinary free cortisol late night salivary cortisol low dose dexamethasone suppression test

how to localise cause of cushings disease biochemically?

identify if ACTH is high/low if low it is likely adrenal if high it is likely pituitary/hypothalamic/adrenal

clinical features of primary hyperaldosteronism

hypokalaemia significant hypertension alkalosis due to loss of H in urine

causes of primary hyperaldosteronism

adrenal adenoma - conns bilateral adrenal hyperplasia genetic mutations unilateral hyperplasia

diagnosis of primary hyperaldosteronism

measure plasma aldosterone and renin and express as ratio rasied ratio do a saline suppression test failure of aldosterone to suppress by >50% with 2L confirms Adrenal CT/adrenal vein sample

surgical management of primary hyperaldosteronism

for adenoma unilateral laparoscopic adrenalectomy only if confirmed by CT and adrenal vein sample

medical management of primary hyperaldosteronidm

bilateral adrenal hyperplasia | use spironolactone of eplerenone

what is the main enzyme deficiency in congenital adrenal hyperplasia

21a-hydroxylase deficiency

diagnosis of congenital adrenal hyperplasia

basal or stimulated 17-OH progesterone

classical presentation of congenital adrenal hyperplasia

adrenal insufficiency biochemical pattern addisons - low Na and high K poor weight gain

non-classical presentation of congenital adrenal hyperplasia

``` hirsutism acne oligomenorrhoea precocious puberty infertility/subinfertility ```

management of congenital adrenal hyperplasia

recognition, glucocorticoid replacement and mineralocorticoid replacement in some surgical correction in adults, control androgen excess and restore fertility

what amino acids are catecholamines derived from?

dopamine, derived from tyrosine

what syndromes are associated with phaeo

neurofibromatosis MEN2a von hippel lindau tuberous sclerosis

classic triad of phaeo? other symptoms?

``` headache, hypertension, sweating palpitations anxiety and fear constipation flushing incidental FHx ```

signs of phaeo

``` hypertension postural hypotension pallor bradycardia/tachycardia pyrexia ```

signs of complications in phaeo

``` left ventricle failure myocardial necrosis stroke shock paralytic ileus of bowel ```

biochemical abnormalities in phaeochromocytoma

``` hyperglycaemia high haematocrit low potassium mild hypercalcaemia lactic acidosis ```

10% rules in phaeo?

``` 10% malignant 10% bilateral 10% extra adrenal 10% associated with hyperglycaemia 10% children 10% familial ```

who to investigate for phaeo

``` resistant HTN HTN in the young classical symptoms FHx consider in hyperglycaemia and HTN ```

diagnosis of pheochromocytoma

2x 24hr catecholamine urinary MRI/CT abdo/body MIBG PET

management of pheochromocytoma

``` full alpha and beta blockade fluid/blood replacement surgical chemo, radiolabelled MIBG biochemical and radiolabelled follow up test for associated genetic conditions/screening family members ```

how is cushings diagnosed from obesity

``` thin skin, bruising prox myopathy osteoporosis conjunctival oedema frontal balding in women ```

what can lead to false positives in cushings diagnosis

alcohol/depression | exogenous steroid