Hypothalamic and Pituitary Flashcards
A 34-year-old woman is being prepared for thyroidectomy. As part of the preparation, she is given a solution containing high iodide concentration. She wonders why she is being treated with something that is added to food (salt). The explanation is that
A - iodide in food is poorly absorbed.
B - iodide in food is rapidly taken up by skeletal muscle.
C - low concentrations of iodide are required for thyroxine synthesis, but high concentrations inhibit thyroxine synthesis and release.
D - iodide in food is not utilized by the thyroid gland.
E - high concentrations of iodide block the TRH receptor on the pituitary gland.
C - low concentrations of iodide are required for thyroxine synthesis, but high concentrations inhibit thyroxine synthesis and release.
A 38-year-old South American woman has a large protrusion on her neck but is otherwise asymptomatic. Her condition is caused by a dietary deficiency of
A - iron.
B - magnesium.
C - potassium.
D - sodium.
E - iodine.
E - iodine.
A 22-year-old woman has signs of hyperthyroidism. Her doctor orders blood tests to determine the pituitary regulation of thyroid function. Which of the following tests will be most helpful?
A - Iodine
B - T4—thyroxine
C - T3—triiodothyronine
D - TSH—thyroid-stimulating hormone
E - TRH—thyroid-releasing hormone
D - TSH—thyroid-stimulating hormone
A 68-year-old woman has increasing lethargy, slight weight gain, and the onset of cognitive impairment. A serum TSH is slightly elevated and a T4 is within normal limits. She is a candidate for
A - TRH.
B - levothyroxine.
C - methimazole.
D - iodide.
E - radioactive iodine.
B - levothyroxine.
A 25-year-old woman has been treated with thyroxine for hypothyroidism. She has become pregnant. She complains now of being constantly fatigued. The proper course of action would be to
A - do nothing, fatigue is normal during pregnancy.
B - increase the iodine in her diet.
C - measure her serum TSH during the first trimester and adjust her thyroxine dose based on the result.
D - double her dose of thyroxine.
E - decrease the dose of thyroxine as the need for thyroid replacement therapy decreases during pregnancy.
C - measure her serum TSH during the first trimester and adjust her thyroxine dose based on the result.
A 48-year-old woman with Graves disease with severe hyperthyroidism is being treated with radioactive iodine. She is also being treated with methimazole because of
A - the long period of time before hyperthyroidism is controlled by radioactive iodine.
B - the expectation that radioactive iodine will be ineffective.
C - methimazole is better absorbed than radioactive iodine.
D - methimazole will counteract the side effects of radioactive iodine.
E - radioactive iodine is not active unless administered with methimazole.
A - the long period of time before hyperthyroidism is controlled by radioactive iodine.
A 73-year-old man with a history of surgery for a benign thyroid nodule when he was 50 years old is now euthyroid but has developed a cardiac arrhythmia. Which of the antiarrhythmic drugs listed below might cause him to develop iodine-induced hypothyroidism?
A - Quinidine
B - Amiodarone
C - Diltiazam
D - Propranolol
E - Digoxin
B - Amiodarone
A 53-year-old woman with the diagnosis of Graves disease is being treated with radioactive iodine. She should be warned of the high likelihood of
A - hyperthyroidism.
B - iodism.
C - hypothyroidism.
D - thyroid nodules.
E - thyroid cancer.
C - hypothyroidism.
A 78-year-old woman has received GH injections from an antiaging clinic. She is likely to experience which of the following effects?
A
Growth of the long bones in her legs
B
Carpal tunnel syndrome
C
Blurred vision
D
Decreased hearing
E
A metallic taste
B
Carpal tunnel syndrome
A 6-year-old boy is diagnosed with central or GnRH-dependent precocious puberty. He is being treated with nafarelin, a GnRH analog, as a nasal spray. GnRH analogs are effective in precocious puberty because they
A
downregulate GnRh receptors on pituitary gonadotropes.
B
block the action of testosterone on muscle cells.
C
stimulate testicular estrogen synthesis.
D
antagonize the effect of luteinizing hormone (LH).
E
antagonize the effect of GnRH release from the hypothalamus.
A
downregulate GnRh receptors on pituitary gonadotropes.
A 20-year-old male cyclist is suspected of using performance-enhancing drugs. Although his urine testosterone concentration is elevated, his testosterone/epitestosterone (T/E) (a measure of exogenous testosterone administration) ratio is normal. He has achieved this state by the use of which of the following?
A
Estrogen
B
Progestin
C
Human chorionic gonadotropin (hCG)
D
Low dose testosterone
E
Growth hormone (GH)
C
Human chorionic gonadotropin (hCG)
A 4-year-old boy with short stature is diagnosed with growth hormone (GH) deficiency. His GH replacement therapy should be continued until
A
he is in the 90th percentile on growth charts.
B
he is in the 60th percentile on growth charts.
C
his epiphyses are fused.
D
he begins to develop secondary sex characteristics.
E
he has permanent teeth.
C
his epiphyses are fused.
A 22-year-old man is determined to have impaired fertility secondary to gonadotropin deficiency. He is being treated with recombinant FSH. The most common side effect with gonadotropin therapy is
A
hirsutism.
B
alopecia.
C
erectile dysfunction.
D
dry skin.
E
gynecomastia.
E
gynecomastia.
Which drug is used to reduce secretion of
gonadotropins and gonadal steroids in children with
precocious puberty?
(A) cabergoline
(B) menotropins
(C) leuprolide
(D) gonadorelin
(E) octreotide
(C) leuprolide
Which drug for treating acromegaly acts by blocking
receptors for growth hormone?
(A) pegvisomant
(B) somatropin
(C) octreotide
(D) leuprolide
(E) cabergoline
(A) pegvisomant
