pituitary hormone regulation & presentation of pituitary disease Flashcards
describe blood supply of anterior pituitary
anterior pituitary has no arterial blood supply but receives
blood through a portal venous
circulation from the
hypothalamus
describe the pituitary - thyroid axis
hypothalamus - TRH
pituitary - TSH
thyroid - T3 &T4
which pituitary hormones are regulated by hypothalamus
- GHRH & SMS
- GnRH
- CRH
- TRH
- Dopamine
which pituitary hormones are regulated by pituitary
- GH
- LH & FSH
- ACTH
- TSH
- Prolactin
examples of pituitary diseases
*Benign pituitary adenoma
* Craniopharygioma
* Trauma
* Apoplexy / Sheehans
* Sarcoid / TB
what are the 3 vital signs of presentation for diagnosing tumours.
- pressure on local structures
- pressure on normal pituitary
- functioning tumour
disease caused by tumours pressing on local structures
bitemporal hemianopia
disease caused by tumours pressing on pituitary
hypopituitarism
diseases caused by tumours impacting functioning tumours (3)
– Prolactinoma
– Acromegaly
– Cushing’s disease
characteristics of prolactinoma
*More common in women
* Present with galactorrhoea / amenorrhea / infertility
* Loss of libido
* Visual field defect
treatment of prolactinoma
dopamine agonist eg
Cabergoline or bromocriptine
3 questions to ask a patient with a pituitary tumour
- Is it pressing on optic chiasm
- Are they hypopituitary
- Do they have a functioning
tumour
what does hypothalamus produce in the GH/ IGF-I axis
hypothalaums -> GHRH or SMS
what does GHRH do
GHRH -> increases the amount of growth hormone produced by the pituitary, which then goes to the liver
what does SMS/GHIH do
SMS -> decreases GH production from the pituitary so that less goes to the liver
