Thyrotropin-releasing hormone (TRH) infusion causes
- stimulation of prolactin release by the pituitary
- inhibition of thyroxine production
- stimulation of ACTH production by the pituitary
- stimulation of growth hormone production
- all of the above
Serum thyrotropin levels in hyperthyroidism:
- enhanced
- suppressed
TSH fails to rise after TRH administration: this clinical condition is most likely:
- primary hyperthyroidism
- secondary (pituitary) hypothyroidism
- both
- neither
Unusual pituitary tumor cell responses to TRH may result in:
- acromegaly
- Cushing's disease
- prolactin release failure
- none of the above
- A, B & C
Thyroid-stimulating hormone (thyrotropin, TSH) is synthesized at this site:
- hypothalamus
- anterior pituitary
TSH subunit that confers thyroid specificity:
- alpha
- beta
- both
- neither
Mechanism of thyrotropin action -- results in ultimately increased thyroid hormone production:
- activation of thyroid cell IP3 system
- activation of guanylyl cyclase system
- activation of adenylyl cyclase system
- blockade of beta adrenergic receptors
- through alpha adrenergic receptor antagonism
Primary thyrotropin (TSH) degradation site:
- liver
- kidney
- excreted unchanged; no degradation
Hypothalamic hormone causing pituitary release of beta-endorphins and ACTH:
- TRH
- TSH
- CRH
- adrenocorticotropin
ACTH adrenocortical stimulation results in:
- cholesterol esterases activity
- reduced mineralocorticoid production
- adrenal atrophy
- skin depigmentation