Endocrinology

Because of infertility problems, a physician would like to determine when a woman ovulates. The physician orders serial assays of plasma progesterone. From these assays, how can the physician recognize when ovulation occurs? A. After ovulation, progesterone rapidly increases. B. After ovulation, progesterone rapidly decreases. C. Right before ovulation, progesterone rapidly increases. D. There is a gradual, steady increase in progesterone throughout the menstrual cycle.

A. After ovulation, progesterone rapidly increases.

Which of the following is the major mineralocorticoid? A. Aldosterone B. Cortisol C. Corticosterone D. Testosterone

A. Aldosterone

Which of the following would be elevated in the blood in medullary carcinoma of the thyroid? A. Calcitonin B. Thyroxine C. Catecholamines D. Secretin

A. Calcitonin

Which of the following is the most potent estrogen and is considered to be the true ovarian hormone? A. Estriol (E3) B. Estrone (E1) C. 17B-Estradiol (E2) D. 16a-Hydroxyestrone

C. 17B-Estradiol (E2)

Which of the following hormones initiates its response by binding to cytoplasmic receptors? A. Estradiol B. Epinephrine C. Growth hormone D. Follicle-stimulating hormone

A. Estradiol

In a patient that who is suspected of having pheochromocytoma, measurement of which of the following would be most useful? A. Metanephrine B. Homovanilic acid C. 5-Hydroxyindoleacetic acid D. Homogentisic acid

A. Metanephrine

How is the majority of reverse T3 (rT3) made? A. Peripheral deiodination of T4 B. Peripheral deiodination of T3 C. From T3 in the thyroid gland D. From thyroglobulin in the thyroid gland

A. Peripheral deiodination of T4

What effect would a low-salt diet, upright position, and diuretics have on the following test results? A. Renin (increased), aldosterone (increased), hypernatremia, hypokalemia B. Renin (increased), aldosterone (decreased), hypernatremia, hypokalemia C. Renin (decreased), aldosterone (decreased), hyponatremia, hyperkalemia D. Renin (decreased), aldosterone (increased), hyponatremia, hyperkalemia

A. Renin (increased), aldosterone (increased), hypernatremia, hypokalemia

What is the predominant form of thyroid hormone in the circulation? A. Thyroxine B. Triiodothyronine C. Diiodotyrosine D. Monoiodotyrosine

A. Thyroxine

Which of the following is the most common cause of the adrenogenital syndrome called congenital adrenal hyperplasia, and which test is used for its diagnosis? A. 17a-Hydroxylase deficiency; progesterone assay B. 21-Hydroxylase deficiency; 17a-hydroxyprogesterone assay C. 3B-Hydroxysteroid dehydrogenaseisomerase deficiency; 17a-hydroxypregnenolone assay D. 11B-Hydroxylase deficiency; 11-deoxycortisol assay

B. 21-Hydroxylase deficiency; 17a-hydroxyprogesterone assay

As a screening test for Cushing's syndrome, the physician wishes to see whether a patient exhibits normal diurnal rhythm of his cortisol secretion. At what time should the specimens be drawn for plasma cortisol determination? (Assume a daytime work schedule for the patient.) A. 6 A.M., 2 P.M. B. 8 A.M., 4 P.M. C. 12 noon, 6 P.M. D. 12 noon, 12 midnight

B. 8 A.M., 4 P.M.

Plasma renin activity (PRA) measurements are usually made by measuring which of the following using immunoassay? A. Angiotensinogen B. Angiotensin I C. Angiotensin II D. Angiotensin-converting enzyme

B. Angiotensin I

Diabetes insipidus is associated with depressed secretion of which of the following hormones? A. Prolactin B. Antidiuretic hormone C. Growth hormone D. Oxytocin

B. Antidiuretic hormone

Once synthesized, the thyroid hormones are stored as a component of thyroglobulin in what area of the thyroid gland? A. Epithelial cell wall of the follicle B. Colloid in the follicle C. Isthmus of the thyroid gland D. Extracellular space of the thyroid gland

B. Colloid in the follicle

An elevated level of which of the following hormones will inhibit pituitary secretion of adrenocorticotropic hormone (ACTH)? A. Aldosterone B. Cortisol C. 17B-Estradiol D. Progesterone

B. Cortisol

The presence of a very high titer for antithyroglobulin antibodies and the detection of antithyroid peroxidase antibodies is highly suggestive of what disorder? A. Pernicious anemia B. Hashimoto thyroiditis C. Multinodular goiter D. Thyroid adenoma

B. Hashimoto thyroiditis

Which of the following tissues does not secrete steroid hormones? A. Ovaries B. Pituitary gland C. Testes D. Adrenal cortex

B. Pituitary gland

Thyroid-releasing hormone (TRH) is given to a patient. Serum thyroid-stimulating hormone (TSH) levels are taken before and after the injection, and the values are the same - low. This patient probably has which of the following disorders? A. Primary hypothyroidism B. Secondary hypothyroidism C. Tertiary hypothyroidism D. Iodine deficiency

B. Secondary hypothyroidism

Which of the following is not associated with growth hormone? A. Somatotropin B. Secreted by posterior pituitary C. Hypersecretion results in acromegaly D. Affects lipid, carbohydrate, and protein metabolism

B. Secreted by posterior pituitary

When performing parathyroid surgery for adenoma resection, parathyroid hormone is quantified at three points relative to the surgical procedure: baseline prior to incision, second baseline with gland exposure, and third sample at post-excision. Which of the following is not correct in assessing the PTH values? A. The second baseline value should be higher than the first baseline. B. The first baseline value should be the highest value of the three samples. C. The post-excision value should be at least 50% of or lower than the second baseline. D. The lack of decrease in the PTH value post-excision indicates possible multigland disease.

B. The first baseline value should be the highest value of the three samples.

What is the major carrier protein of the thyroid hormones in the blood? A. Albumin B. Thyroxine-binding globulin C. Thyroxine-binding prealbumin D. Thyroglobulin

B. Thyroxine-binding globulin

Which of the following is the Hollander insulin test test used to confirm? A. Hyperglycemia B. Vagotomy C. Pancreatectomy D. Insulinoma

B. Vagotomy

A 30-year-old woman is admitted to the hospital. She has truncal obesity, buffalo humpback, moon face, purple striae, hypertension, hyperglycemia, increased facial hair, acne, and amenorrhea. The physician orders endocrine testing. The results are as follows: Urine free cortisol - increased Serum cortisol (8 A. M.) - increased Plasma ACTH - decreased Dexamethasone suppression test: overnight low dose - no suppression of serum cortisol, high dose - no suppression of serum cortisol What is the most probable diagnosis? A. Pituitary adenoma B. Ectopic ACTH lung cancer C. Adrenocortical carcinoma D. Addison disease

C. Adrenocortical carcinoma

When do the highest levels of gonadotropins occur? A. During the follicular phase of the menstrual cycle B. During the luteal phase of the menstrual cycle C. At the midpoint of the menstrual cycle D. Several days prior to ovulation

C. At the midpoint of the menstrual cycle

Why are the total thyroxine (T4) levels increased in pregnant women and woman who take oral contraceptives? A. Inappropriate iodine metabolism B. CHanges in tissue use C. Changes in concentration of thyroxine-binding globulin (TBG) D. Changes in thyroglobulin synthesis

C. Changes in concentration of thyroxine-binding globulin (TBG)

During pregnancy in the second trimester, human chorionic gonadotropin (hCG) levels _____________ and progesterone and estriol levels ___________________ . A. Increase, increase B. Increase, decrease C. Decrease, increase D. Decrease, decrease

C. Decrease, increase

In a patient suspected of having primary myxedema, one would expect the following serum results: free thyroxine (FT4) _________________, thyroid hormone binding ratio (THBR) ____________________, and thyroid-stimulating hormone (TSH) _____________________. A. Decreased, increased, decreased B. Increased, increased, decreased C. Decreased, decreased, increased D. Increased, decreased, increased

C. Decreased, decreased, increased

The adrenal medulla secretes which of the following in the greatest quantity? A. Metanephrine B. Norepinephrine C. Epinephrine D. Dopamine

C. Epinephrine

Zollinger-Ellison syndrome is characterized by an elevated blood level of which of the following? A. Trypsin B. Pepsin C. Gastrin D. Cholecystokinin-pancreozymin

C. Gastrin

What would be an example of ectopic hormone production? A. Prolactin production by pituitary tumors B. Calcitonin production by thyroid tumors C. Growth hormone production by lung tumors D. Cortisol production by adrenal tumors

C. Growth hormone production by lung tumors

Secretion of hormones by the anterior pituitary may be controlled by the circulating levels of hormones from the respective target gland, as well as hormones secreted by what organ? A. Posterior lobe of the pituitary gland B. Intermediate lobe of the pituitary gland C. Hypothalamus D. Adrenal medulla

C. Hypothalamus

In a patient with suspected primary hyperthyroidism associated with Graves disease, one would expect the following laboratory serum results: free thyroxine (FT4) _____________________, thyroid hormone binding ratio (THBR) ____________________, and thyroid-stimulating hormone (TSH) _______________. A. Increased, decreased, increased B. Increased, decreased, decreased C. Increased, increased, decreased D. Decreased, decreased, increased

C. Increased, increased, decreased

Which of the following is not quantified in the triple test for Down syndrome? A. a1-Fetoprotein B. Unconjugated estriol C. Progesterone D. Human chorionic gonadotropin

C. Progesterone

Of which of the following is 5-hydroxyindoleacetic acid (5-HIAA) the primary metabolite? A. Epinephrine B. Norepinephrine C. Serotonin D. Prolactin

C. Serotonin

The secretion of which of to the following is controlled by growth hormone? A. Growth hormone-releasing hormone B. Corticotropin-releasing hormone C. Somatomedin D. Somatostatin

C. Somatomedin

Which of the following is an autoantibody that binds to TSH receptor sites on thyroid cell membranes, preventing thyroid stimulating hormone from binding? A. Antithyroglobulin antibodies B. Thyroid antimicrosomal antibodies C. Thyrotropin-receptor antibodies D. Antithyroid peroxidase antibodies

C. Thyrotropin-receptor antibodies

What does the concentration of urinary free cortisol mainly reflect? A. Total serum cortisol B. Conjugated cortisol C. Unbound serum cortisol D. Protein-bound serum cortisol

C. Unbound serum cortisol

During pregnancy, estriol is synthesized in the placenta from ____________ formed in the _____________________. A. Estradiol, mother B. Estradiol, fetus C. 16a-Hydroxy-DHEA-S, mother D. 16a-Hydroxy-DHEA-S, fetus

D. 16a-Hydroxy-DHEA-S, fetus

What percentage decrease in plasma or urinary estriol, in comparison with the previous day's level, is considered significant during pregnancy? A. 5 B. 10 C. 25 D. 40

D. 40

Which of the following compounds is not a precursor of the estrogens? A. Progesterone B. Testosterone C. Cholesterol D. Aldosterone

D. Aldosterone

A 4-year-old female presents with a palpable abdominal mass, pallor, and petechiae. Based on family history, clinical findings, and the patient's physical examination, neuroblastoma is suspected. Which of the following does not support such a diagnosis? A. Increased blood dopamine levels B. Increased blood epinephrine levels C. Increased urinary homovanillic acid D. Decreased urinary vanillylmandelic acid

D. Decreased urinary vanillylmandelic acid

The placenta secretes numerous hormones both protein and steroid. Which of the following hormones is not secreted by the placenta? A. Human chorionic gonadotropin (hCG) B. Estrogen C. Human placental lactogen (HPL) D. Luteinizing hormone (LH)

D. Luteinizing hormone (LH)

A patient is suspected of having Addison disease. His symptoms are weakness, fatigue, loss of weight, skin pigmentation, and hypoglycemia. His laboratory tests show low serum sodium and chloride, elevated serum potassium, and elevated urine sodium and chloride levels. The serum cortisol is decreased and the plasma ACTH is increased. To make a definitive diagnosis, the physician orders an ACTH stimulation test, and serum cortisol levels are measured. If the patient has primary hypoadrenocortical function (Addison disease), what would be the expected level of serum cortisol following stimulation? if the patient has hypopituitarism and secondary hypoadrenocortical function, what would be expected level of serum cortisol following stimulation? A. Increase from baseline; decrease from baseline B. Decrease from baseline; increase from baseline C. Slight increase from baseline; no change from baseline D. No change from baseline; slight increase from baseline

D. No change from baseline; slight increase from baseline

Which of the following functions as an inhibiting factor for somatotropin release? A. Gonadotropin-releasing hormone B. Growth hormone-releasing hormone C. Somatomedin D. Somatostatin

D. Somatostatin

Which of the following is the most potent androgen? A. Androstenedione B. Dehydroepiandrosterone C. Androsterone D. Testosterone

D. Testerone