endocrinology Flashcards
what part of brain regulates pituitary gland?
hypothalamus
3 causes of bushings syndrome?
- exogenous steroids
- ACTH-secreting pituitary tumour
- cortisol secreting adrenal tumour
what is the HPA axis?
hypothalamus secretes CRH
pituitary secretes ACTH
adrenal cortex secretes cortisol
how does cushings affect BP + glucose levels?
hypertension
hyperglycaemia
how will cushings syndrome respond to dexamethasone?
will not be supressed
4 causes of Addisons disease?
- autoimmunity
- suppression of HPA axis following steroid therapy
- adrenal tumours
- pituitary failure
what is cushings syndrome
hypercortisolism
oral feature of Addisons?
pigmented buccal mucosa
how does Addisons affect BP + glucose levels?
hypotension
hypoglycaemia
treatment for Addisons?
hydrocortisone or fludrocortisone
what is the thyroid axis?
hypothalamus secretes TRH
pituitary secretes TSH
thyroid secretes thyroxine
what is main role of thyroid?
controls metabolism
3 causes of hyperthyroidism
- autoimmune - graves disease
- multi nodular goitre
- thyroid adenoma
very rarely due to problem in pituitary
example of an antithyroid drug?
carbimazole
iodide also used to treat hyperthyroidism
4 causes of hypothyroidism
- autoimmune destruction
- surgical removal of thyroid
- radio-iodine treatment
- secondary to decreased TSH in pituitary disease
what is myxoedema and what causes it?
caused by hypothyroidism
infilitrain of interstitial tissue with proteinaceous fluid
coarse face, bags under eyes, croaky voice
how to treat hypothryoidism?
thyroxine tablets - levothryoxine
what is the GH axis?
hypothalamus secretes GHRH
pituitary secretees GH
liver produces IGF-1
cause of acromegaly?
pituitary tumour secreting GH
how does acromegaly affect BP + glucose levels?
hypertension
hyperglycaemia
how does PTH effect calcium levels
PTH increase blood calcium levels
what causes hyperPTH
primary - parathyroid tumour
secondary - response to low calcium/vit D
how may hypercalceima be identified on a dental radiograph?
loss of lamina dura
reduced cortical width of mandible + ground glass appearance
2 causes of hypoparathyroidism
- autoimmune
2. damage to parathyroid during surgery