Adrenal gland and steroids Flashcards
ILO 8.8a: be familiar with the underlying disease processes of the common medical disorders affecting the body
describe where the adrenal gland is and what it does
- triangle shaped
- located on top of the kidneys
- regulate important bodily functions - metabolism, immunity, blood pressure, stress response, development of sexal characters
what are the two parts of the adenal gland? what does each part do?
medulla
* inner part that relases adrenaline and noradrenaline
* controls blood pressure, heart rate, sweating
cortex
* outer part that releases glucocorticoid, mineralocorticoid steroid hormones and small amounts of sex steroid hormones
what makes up the adrenal cotex? what does each part do?
- zona glomerulosa - produces mineralocorticoids (aldosterone)
- zona fasciculata - produces glucocorticoids (cortisol)
- zona reticularis - produces adrenal androgens
where is cortisol secreted? what does it affect?
- secreted in the zona fasciculata in the cortex of the adrenal gland
- affects the nervous, immune, cardiovascular, respiratory and reproductive system
what are the physiological effects of cortisol?
- regulates stress response
- antagonist to insulin
- lowers immune reactivity
- raises blood pressure
- inhibits bone synthesis
how are the adrenal gland hormones regulated?
- hypothalamus releases CRH (corticotropin releasing hormone)
- CRH acts on the pituitary gland which releases ACTH (adrenocorticotropic hormone)
- ACTH acts on the adrenal cortex to release aldosterone and cortisol etc.
what are therapeutic steroids? what do they treat?
- man-made version of the adrenal hormones
- anti-inflammatories
- glucocorticoid effect - immunosuppression, reduces inflammation
- mineralcorticoid effect - salt and water retention, hypertension
- used for: asthma, COPD, eczema, arthiritis, IBS, MS
what are the adverse effects of therapeutic steroids?
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- hypertension
- type 2 diabetes
- osteoporosis
- increased infection risk
- peptic ulceration
- thinning of the skin
- easy bruising
- cataracts and glaucoma
- hyperlipidaemia (high colesterol)
- increased cancer risk
- psychiatric disturbance
what are examples of therapeutic steroids? what are their equivalent strengths?
5
- hydrocortisone (1mg=1mg)
- prednisolone (1mg=4mg)
- triamcinolone (1mg=5mg)
- dexamethasone (1mg=25mg)
- betamethasone (1mg=30mg)
- e.g. 5mg prednisolone = 20mg hydocorisone
what are some causes of adrenal hyperfunction?
- glucocorticosteroids - Cushing’s syndrome
- aldosterone - Conn’s disease
what is cause of adrenal hypofunction?
Addison’s disease - destruction of adrenal tissue
what is Cushing’s syndrome caused by?
- occurs when there is excess cortisol in the body for a long time
- due to **adrenal adenoma or hyperplasia, pituitary adenoma producing ACTH, lung tumour producing ACTH, steroid medications **
when is Cushing’s syndrome classed as Cushing’s disease?
when there is a pituitary adenoma that produces excess ACTH
* secondary failure (control failure)
what are the symptoms of Cushing’s syndrome?
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- diabetes mellitus feautes
- poor resistace to infections
- osteoporotic changes
- psychiatric disorders
- hirsutism (excess hair)
- skin and mucosa pigmentation
- amenorrhoea, impotence and infertility
what are the signs of Cushing’s disease?
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- centripetal obesity - moon face, buffalo hump
- hypertension
- thick skin and purpura - red or purple spots on skin
- muscle weakness
- osteoporotic changes and fractures
how would you diagnose Cushing’s syndrome?
- high 24hour urinary cortisol excretion
- abnormal dexamethasone suppression tests - given to suppress ACTH
- CRH tests
what results would you see in a CRH test for Cushing’s disease?
- high CRH
- high ACTH
what are some causes of primary adrenal hypofunction?
3
- autoimmune gland destruction
- infection
- infarction
what are some causes of secondary adrenal hypofunction?
- compression from other adenoma
- Sheehan’s syndrome
what is Addison’s disease? what is it caused by?
- primary adrenal insufficiency due to autoimmune disease
- insufficient cortisol and aldosterone
- increased levels of ACTH
what are the symptoms of Addison’s disease?
3
- weakness
- anorexia
- loss of body hair (females)
what are the signs of Addison’s disease?
4
- postural hypertension (absence of aldosterone, effecting glucocorticoids)
- weight loss and lethargy
- hyperpigmentation (not in secondary hypofunction) - scars, oral mucosa, skin due to ACTH secretion
- vitiligo
how would you diagnose Addison’s disease?
- blood test - high ACTH levels
- negative synACTH test (no plasma cortisol rise inresponse to ACTH injection)
how would you treat Addison’s disease?
hormone replacement
* cortisol - hydrocortisone, prednisolone
* aldosterone - fludrocortisone
what test results would you see in primary hyperfunction of the adrenal gland?
- low ACTH
- high cortisol
- negative synACTH
what test results would you see in secondary hyperfunction of the adrenal gland?
- high ACTH
- high cortisol
- positive synACTH
what test results would you see in primary hypofunction of the adrenal gland?
- high ACTH
- low cortisol
- negative synACTH
what test results would you see in secondary hypofunction of the adrenal gland?
- low ACTH
- low cortisol
- positive synACTH
how can you treat adrenal hyperfunction?
- detect cause - pituitary, adrenal gland, ectopic (lung)
- surgery - pituitary or adrenal partial/complete adrenalectomy
what is adrenal crisis?
life threatening condition when the adrenal hormone levels fall significantly
what are the signs of adrenal crisis?
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- fever
- convulsions
- hypogylcaemia
- hypotension
- vomiting
- hypovolaemic shock
- hyponatremia - low sodium
- coma
when do cortisol levels rise?
- physical stress
- infection
what is steroid cover?
- increased steroid dose to prevent adrenal crisis when increased physiological requirement is anticipated
- infection
- surgery
- physiological stress
what are the dental aspects of steroids and adrenal gland disorders? with which patients may steroid cover be required?
- steroid cover may be needed for patients with Addison’s disease, secondary adrenal insufficiency, taking more than 5mg prednisolone
- liase with physician for infections
- candidiasis in Cushing’s syndrome
- oral pigmentation in Addison’s/Cushings due to high ACTH levels
