Endocrinology I Flashcards
which hormone is responsible for directly stimulating tissue growth?
IGF-1 whose secretion is stimulated by GH
what type of cell makes up most of the pituitary gland?
somatotroph (50%)
what type of cell is the least abundant in the pituitary gland?
thyrotrophs (<10%)
what is the most common type of hormone secreting pituitary tumor?
prolactin
how would you classify most pituitary tumors?
non-malignant (benign)
- non functioning (don’t affect hormone levels)
- hyperfunctioning
what is the size of a microadenoma?
<1cm
what is the size of a macroadenoma?
> 1cm
what are common signs and sxs that go along with pituitary tumors?
- visual field defects
- N/V
- H/A
- hormone specific sxs
what is the most common type of pituitary tumor overall?
non-functioning
micro>macro
what is unique about LH/FSH secreting tumors?
the hormones secreted are not effective, therefor do not produce any clinical manifestations
what is the most common way that microadenomas are found?
incidental finding from a scan that was taken for another reason
what is included in the initial pituitary work up?
- all ant. pit. hormones
- target organ hormones (free T4, cortisol, sex hormones, IGF-1)
- MRI of pit and hypothalamus (w/contrast)-NOT of the WHOLE BRAIN
- ophthalmology referral for pt with macroadenoma and field defects
when is surgery recommended?
- symptomatic tumors
2. macroadenomas
why does reglan cause hyperprolactinemia?
it is a dopamine antagonist
-dopamine secretion inhibits prolactin release
what is a normal prolactin level?
> 30