Pituitary Flashcards
What are the hormones secreted by the anterior pituitary?
- MSH
- FSH
- TSH
- GH
- LH
- ACTH
- PRL
(mish. fish.tish, gh.lh, acth.prl)
What are the hormones secreted by the posterior pituitary?
- ADH
- OXT
What does cold exposure do to the thyroid?
cold –> TRH (hypothalamus) –> TSH (anterior pituitary) –> free T4 (thyroid) which then downregulates TSH from anterior pituitary
(‘hip auntie’)
What causes testosterone to be released?
LH
What causes oestrogen and progesterone to be released?
FSH
What action does cortisol have?
down regulates the production of CRH and ACTH (its precursors)
How is cortisol made?
CRH from the hypothalamus –> ACTH from the pituitary –> cortisol
How is thyroxine made?
TRH from hypothalamus –> TSH from pituitary –> thyroxine
How are testosterone and E2 (oestradiol) made?
GnRh from hypothalamus –> LH/FSH from pituitary –> E2/TEST
How is growth hormone made?
GHRH from hypothalamus –> GH from the pituitary
How is prolactin made?
DA from hypothalamus DOWNREGULATES prolactin production from the pituitary
Where are vasopressin and OXT stored?
in the posterior pituitary from the hypothalamus
Where do all the hormones from the pituitary go?
muscle, liver, fat, breast tissue, gonads, brain, bones etc
What is the best test for pituitary disease?
MRI
What is the most common direction for a pituitary tumour to grow?
upwards as there is bone on either side
What are the types of dynamic testing?
- suppress hormone to check if there is too much still being made
- stimulate hormone to check if there is too little made
What is the insulin stress test?
causes a hypo so the hypothalamus will make cortisol and GH due to stress
What is the synacthen test?
synthetic ACTH is given to test cortisol levels
What is the water deprivation test?
check for ADH production using urine concentration to test for diabetes insipidus
What is the difference between a pituitary microadenoma and a macroadenoma?
Microadenoma is smaller than or equal to 1cm
Macroadenoma is bigger than 1cm
What can pituitary tumours cause?
they can compression other structures so less production from normal tissue
- hypoadrenalism
- hypothyroid
- hypogonad
- GH deficiency
- DI (less common as tumours usually affect anterior pit)
What is the treatment for a tumour causing bitemporal hemianopia?
- transphenoidal surgery
- hormone replacement
What are the causes of raised prolactin?
- physiological: breast feeding, pregnancy, stress and sleep
- pharmacological: dopamine antagonists, antipsychotic
- pathological: hypothyroid, stalk blocking (RTA or iatrogenic) or prolactinoma
What are the differentials for excess sweating?
- post-menopausal
- acromegaly
- hyperthyroidism
- Cushing’s
- Phaeochromocytoma (increased adrenaline and noradrenaline)
