Hypothalamic Pituitary Axis Physiology Flashcards
What are the precursors of cortisol?
CRH in the hypothalamus is changed into ACTH in the pituitary
What are the precursors of thyroxine?
TRH in the hypothalamus is changed into TSH in the pituitary
What are the precursors of testosterone/oestradiol?
GnRH in the hypothalamus changed into LH/FSH in the pituitary
What is the precursor of GH?
GHRH (in the hypothalamus)
What is the precursor of PRL?
DA (in the hypothalamus)
Where are vasopressin and OXT stored?
The posterior pituitary
What causes the clinical presentation of endocrinological diseases?
Size of gland or amount of hormone (may be all three in pituitary)
How are causes of endocrinological diseases investigated?
Size of gland investigated by imaging
Amount of hormone investigated by blood tests
What peripheral hormone is ACTH paired with?
Cortisol
What peripheral hormone is TSH paired with?
Thyroxine
What peripheral hormone is LH/FSH paired with?
Testosterone/oestradiol
What peripheral hormone is GH paired with?
IGF-1
What hormones are included in a usual thyroid function test?
TSH, thyroxine, LH, FSH, testosterone/oestradiol, GH, IGF-1, PRL
When are dynamic tests used?
When baseline tests aren’t sufficient = usually on steroid axis
When are dynamic pituitary stimulation tests used?
If there is too little of a hormone = synacthen stimulation test, insulin stress test/prolonged glucagon test, water deprivation test
