MTB and important from FA Flashcards
(98 cards)
increased sex hormone-binding globulin in MEN –>
lowers free testostosterone –> gynecomastia
decreased sex hormone-binding globulin in WOMEN –>
raises free testosteron –> hirsutism
causes of increased sex hormone-binding globulin
OCP
PREGANCY
increased sex hormone-binding globulin - estrogen levels
unchanged
MC ectopic thyroid tissue site is the
tongue (lingual thyroid)
α subunit is common to (hormones)
WHAT DETERMINES THEIR SPECIFICITY
- TSH 2. LH 3. FSH 4. hCG
β subunit determines their hormone specificity
vasopressin and oxytocin production and secretion (where and transportation)
made in hypothalamus (supraoptic and paraventricular nuclei) and transported to posterior pituitary via neurophysins
insulin release regulators (and how)
- glucose (increases)
- GH (increases)
- β2 agonists (increase)
- cortisol (increase)
- α2 agonists –> decrease insulin release
Dopamine function (hypothalamic pituitary)
decreases prolactin and TSH secretion
GHRH analog?
used for
tesamorelin
used to tread HIV lipodystrophy
TRH funtion
- increases TSH secretion
2. increases prolactin secretion
prolactin secretion is regulated by
- TRH (positively)
- dopamine (negatively)
- prolactin (negatively by increasing dopamine secretion)
- estrogen and progesterone (positively, in pregnany)
somatostatin function (on hypothalamic pituitary axon)
decreases secretion of
- GH
- TSH
TSH is regulated by
- T3/T4 (negatively, decrease sensitivity of TRH)
4. dopamine (negatively)
GH secretion is regulated by
- glucose (negatively)
- somatostatin (negatively, release via negative feedaback by somatomedin)
- GHRH (positively)
- Ghrelin (positively, via GH secretagog receptor)
- somatomedin C (negatively, via somatostatin)
TBG - increased (situations)
estrogen (pregnancy or OCP use)
TBG - decreased (situations)
- hepatic failure
2. steroids
etiology of endogenous hepercortisolism (and percentages)
- Cushing disease (Pituitary production) - 70%
- Adrenals - 15%
- Unknown source of ACTH - 5%
- ecropic ACTH (cancer or carcinoid) - 10%
adrenal disorders - diagnostic algorithm - genarally
- establish the presence of hyperctortisolism
2. establish the cause of hypercotisolism
establish the presence of hyperctortisolism - best initial test
24h urine cortisol
if this is not in the choices: answer 1 mg overnight dexamethasone suppression test or late night salivary cortisol levels (normal exclude)
establish the presence of hyperctortisolism - 1 mg overnight dexamethasone suppression test
1 mg should normally suppress the morning cortisol level –> if this suppression occurs, hypercortisolism can be ecxluded
THERE ARE FP
establish the presence of hyperctortisolism - 24 urine vs 1 mg dexamethasone
24h urine cortisol test is a more specific –> if 24h urine cortisol is elevated -> confirm
causes of FP in 1mg overnight suppresson testing
- Depression
- alcoholism
- obesity
establish the cause of hypercortisolism - best initial test
ACTH testing is the best initial test determine the cause (source) or location of hypercrtisolism
- low –> adrenal source or exogenous
- elevated –> pituitary, ectopic production (carcinoid, lung cancer)