A 27-year-old woman comes to the physician because of a 2-month history of palpitations, diaphoresis, and a 5-kg (11-lb) weight loss. Her pulse is 101/min and blood pressure is 141/84 mm Hg. Physical examination shows a fine tremor when the fingers are outstretched. After confirmation of the diagnosis, treatment is begun with an antithyroid medication. The physician emphasizes the need for adequate contraception because of the increased risk of severe fetal malformations associated with the use of this medication, which is why its use is discouraged in the first trimester of pregnancy. Which of the following best describes the mechanism of action of this drug?
AInhibition of thyroid hormone release
BInhibition of peripheral conversion of T4 to T3
CDecreased iodide uptake by follicular cells
DSuppression of thyroid-stimulating hormone release
EInhibition of iodide ion oxidation
A 49-year-old woman presents to the office because of tremors for 2 months. She says that her hands have been shaking a lot, especially when she feels stressed. In addition, she has been sweating more than usual and has lost 8 kg (17.6 lb) in the last 2 months. She has a past medical history of vitiligo. Her vital signs are a heart rate of 98/min, a respiratory rate of 14/min, a temperature of 37.6°C (99.7°F), and a blood pressure of 115/75 mm Hg. Physical examination shows a fine, bilateral hand tremor and a diffuse goiter. Which of the following hormonal imbalances is most likely present?
ALow TSH, high free T4, and high free T3
BHigh TSH, high free T4, and high free T3
CHigh TSH, normal free T4, and normal free T3
DLow TSH, normal free T4, and normal free T3
EHigh TSH, low free T4, and low free T3
An investigator studying hormone synthesis and transport uses immunocytochemical techniques to localize a carrier protein in the central nervous system of an experimental animal. The investigator finds that this protein is synthesized together with a specific hormone from a composite precursor. The protein is involved in the transport of the hormone from the supraoptic and paraventricular nuclei to its destination. The hormone transported by these carrier proteins is most likely responsible for which of the following functions?
AStimulation of thyroglobulin cleavage
BUpregulation of renal aquaporin-2 channels
CHyperplasia of the adrenal zona fasciculata
DIncreased insulin-like growth factor 1 production
EMaturation of primordial germ cells
+ 7 more in the PDF
Browse all chapters