Clinical Chemistry (Endocrinology) Flashcards
350 - 394
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
An elevated level of which of the following hormones will inhibit pituitary secretion of adrenocorticotropic hormone (ACTH)?
A. Aldosterone
B. Cortisol
C. 17 B-Estradiol
D. Progesterone
Which of the following is the major mineralocorticoid?
A. Aldosterone
B. Cortisol
C. Corticosterone
D. Testosterone
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
What effect would a low-salt diet, upright
position, and diuretics have on the
following test results?
A. Renin ↑, aldosterone T↑, hypernatremia, hypokalemia
B. Renin ↑, aldosterone ↓, hypernatremia, hypokalemia
C. Renin ↓, aldosterone ↓, hyponatremia, hyperkalemia
D. Renin ↓, aldosterone ↓, hyponatremia, hyperkalemia
As a screening test for Gushing syndrome, the physician wishes to see whether a patient exhibits normal diurnal rhythm in his or her cortisol secretion. At what time should the specimens be drawn for plasma cortisol determination?
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
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 level 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 the 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
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
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
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. 11 (3-Hydroxylase deficiency; 11-deoxycortisol assay
Which of the following is the most potent androgen?
A. Androstenedione
B. Dehydroepiandrosterone
C. Androsterone
D. Testosterone
Which of the following tissues does not secrete steroid hormones?
A. Ovaries
B. Pituitary gland
C. Testes
D. Adrenal cortex
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. 17p-Estradiol (E2)
D. 16a-Hydroxyestrone
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
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
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
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)
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
