Clinical Chemistry Review CLS 540 exam 4

What would be the predicted results for the following laboratory results for a patient with primary hypothyroidism?

Laboratory tests (serum): Total T4 (TT4), FT4, TSH

A. Below normal TT4, below normal FT4, below normal TSH

B. Below normal TT4, elevated FT4, elevated TSH

C. Elevated TT4, below normal FT4, elevated TSH

D. Below normal TT4, below normal FT4, elevated TSH

D. Below normal TT4, below normal FT4, elevated TSH

Free thyroxine assays measure:

A. Total thyroxine levels

B. Only the bound thyroxine level

C. Only the unbound thyroxine level

D. The sum of the bound and unbound thyroxine

C. Only the unbound thyroxine level

Thyroid hormones are derived from which of the following amino acids?

A. Tryptophan

B. Methionine

C. Histidine

D. Tvrosine

D. Tvrosine

The recommended initial thyroid function test for either an asymptomatic patient or a patient with symptoms which may be related to a thyroid disorder is:

A. Free Thyroxine (free T4)

B. Total Thyroxine (T4)

C. Thyroid-stimulating hormone (TSH)

D. Triiodothyronine (T3)

C. Thyroid-stimulating hormone (TSH)

The thyroxine (T4) in target cells is converted into the more biologically active hormone:

A. Thyroglobulin (TG)

B. Triiodothyronine (T3)

C. Diodotyrosine (DIT)

D. Reverse triiodothyronine (rT3)

B. Triiodothyronine (T3)

All of the following proteins transport thyroid hormones except:

A. Gamma globulin

B. Thyroxine-binding globulin

C. Albumin

D. Thyroxine-binding prealbumin

A. Gamma globulin

The storage protein for T4 and T3 that frequently has circulating antibodies against it in chronic thyroiditis is:

A. Albumin

B. Thyroxine-binding globulin

C. Thyroxine-binding prealbumin

D. Thyroglobulin

D. Thyroglobulin

The following results were found on a patient who is overweight, lethargic, intolerant to cold, and slightly anemic: decreased free T4 and increased TSH. Which of the following conditions is the MOST likely diagnosis?

A. Primary hyperthyroidism

B. Secondary hyperthyroidism

C. Primary hypothyroidism

D. Secondary hypothyroidism

C. Primary hypothyroidism

A patient with increased ionized calcium, decreased phosphorus increased alkaline phosphatase, and mild acidosis MOST probably has:

A. Hyperthyroidism

B. Hyperparathyroidism

c. Hypothyroidism

D. Hypoparathyroidism

B. Hyperparathyroidism

The colloid material of the thyroid follicle is PRIMARILY composed of:

A. Thyroglobulin

B. Triiodothyronine

C. Tetraiodothyronine

D. Thyroxine-binding globulin

A. Thyroglobulin

Which of the following thyroid hormones is NOT biologically active?

A. Thyroxine

B. Reverse triiodothyronine

C. Triiodothyronine

D. Tetraiodothyronine

B. Reverse triiodothyronine

Which of the following hormone levels is MOST closely associated with the thyroid status of the patient?

A. T4

B. T3

C. rT3

D. Free T4

D. Free T4

The following results were found on a patient who has lost weight, fatique, intolerant to heat, nervous, and irritable: increased free T4 and decreased TSH. Which of the following conditions is the MOST likely diagnosis?

A. Primary hyperthyroidism

B. Secondary hyperthyroidism

C. Primary hypothyroidism

D. Secondary hypothyroidism

A. Primary hyperthyroidism

Which of the following is a good marker for thyroid cancer?

A. Thyroglobulin

B. Triiodothyronine

C. Tetraiodothyronine

D. Thyroxine-binding globulin

A. Thyroglobulin

The MOST common cause of hyperthyroidism is:

A. Chronic lymphocytic thyroiditis

B. Hashimoto's thyroiditis

C. Myxedema

D. Graves' disease

D. Graves' disease

Which autoimmune antibodies at the highest percentage do patients with Hashimoto's thyroiditis develop?

A. Antithyroglobulin

B. Anti-TSH receptor

C. Thyroid peroxidase antibody

D. Antithyroid-binding globulin

C. Thyroid peroxidase antibody

The accumulation of mucopolysaccharides in the skin and other tissue leading to thickening and doughy induration of the skin is seen in patients with:

A. Graves' disease

B. Myxedema

C. Thyrotoxicosis

D. Cretinism

B. Myxedema

Thyroid hormone T4 and T3 are secreted in response from pituitary stimulation by:

A. CRH

B. TRH

C. TSH

D. Somatostatin

C. TSH

The thyroid synthesis of T4 within the follicular cells is a multi-step process. The organification (the incorporation of iodine into thyroglobulin) step is when:

A. lodine combines with tyrosine residues to form MIT and DIT

B. lodide is trapped in follicular cell and oxidized to iodine for MIT and DIT

C. Protease digest drops of colloid and release T3 and T4 to circulation

D. There is enzymatic coupling of MIT and DIT forms to produce intrathyroglobulinT3

A. lodine combines with tyrosine residues to form MIT and DIT

Congenital hypothyroidism or cretinism, according to the American Academy of Pediatrics, necessitates that all newborns be screened via:

A. Blood test for hyperthyroidism using the genetic markers for Graves' disease

B. Blood spots collected for TSH/backup T4 screening for

hypothyroidism

C. Heel sticks for T4 and T3 using immunoassays for blood

D. Isometric radial circumferences of their thigh muscles prior to discharge

B. Blood spots collected for TSH/backup T4 screening for hypothyroidism

Sick euthyroid syndrome (SES) occurs when a patient has abnormal thyroid hormone levels without the presence of thyroid disease. Which set of results represents the findings on a SES patient?

A. Decreased T3 levels with elevated reverse T3, the patient is on amiodarone for cardiac arrhythmias

B. Elevated TSH, with no increase in T3 and T4, patient has diabetes

C. Elevated TSH with decreased T4, patient who had a baby 4 months ago

D. Decreased TSH with increased T4, patient who exhibits eye orbit prominence

A. Decreased T3 levels with elevated reverse T3, the patient is on amiodarone for cardiac arrhythmias

A serum thyroid panel reveals an increase in total T4, normal TSH, and normal free T4. What is the MOST likely cause of these results?

A. Primary hyperthyroidism

B. Secondary hyperthyroidism

C. Euthyroid with increased thyroxine-binding protein

D. Subclinical hypothyroidism

C. Euthyroid with increased thyroxine-binding protein

A 68-year-old female patient tells her physician of being "cold all the time" and recent weight gain with no change in diet. The doctor orders a TSH level, and the laboratory reports a value of 8.7 mU/L) (reference range: 0.5-5.0 mU/L). This patient most likely has:

A. Primary hypothyroidism

B. Graves' disease

C. TSH-secreting tumor

D. Primary hyperthyroidism

A. Primary hypothyroidism

A female patient during her routine physical exam has blood drawn for a comprehensive metabolic panel (CMP) and thyroid panel due to some medication she is on. Her laboratory findings are within acceptable ranges except her TSH level is decreased. A follow-up thyroid panel test shows only her TSH value is decreased and her free T4 is fine. The physician tells the patient that she has:

A. Primary hypothyroidism

B. Primary hyperthyroidism

C. Secondary hypothyroidism

D. Subclinical hyperthyroidism

D. Subclinical hyperthyroidism

Patients who exhibit an abnormal spasm of the facial muscles when tapped lightly on the cheek (Chvostek's sign) may have:

A. Pseudoparahypothyroidism

B. Secondary hyperparathyroidism

C. Renal tubular acidosis

D. Hypoparathyroidism

D. Hypoparathyroidism

Which of the following statements BEST reflects the diagnostic criteria of primary hyperparathyroidism?

A. No serum parathyroid hormone detected (PTH); no serum calcium

detected

B. Detectable amounts of serum PTH concomitant with elevated total serum calcium

C. Elevated total serum calcium only

D. A normal level of serum PTH and serum calcium

B. Detectable amounts of serum PTH concomitant with elevated total serum calcium

The primary regulator of parathyroid hormone synthesis is the concentration of in the blood.

A. Magnesium

B. Phosphate

C. 1, 25-dihydroxyvitamin D

D. lonized calcium

D. lonized calcium

The presence of increased amounts of _________________ will result in increased reabsorption / absorption of ______________ from the bone, kidneys, and intestine.

A. Parathyroid hormone; phosphate

B. Parathyroid hormone; calcium

C. Thyroxine; vitamin D

D. Thyroxine; magnesium

B. Parathyroid hormone; calcium

The following is an appropriate physiologic response to a fall in extracellular fluid (ECF) calcium.

A. A rise in parathyroid hormone (PTH) and a fall in 1.25

dihydroxyvitaminD

B. A fall in parathyroid hormone (PTH) and a rise in 1.25

dihydroxyvitaminD

C. A rise in parathyroid hormone (PTH) and a rise in 1,25

dihydroxyvitaminD

D. A fall in parathyroid hormone (PTH) and a fall in 1,25

dihydroxyvitamin D

C. A rise in parathyroid hormone (PTH) and a rise in 1,25 dihydroxyvitaminD

Which one of the following statements regarding parathyroid hormone (PTH) is NOT true?

A. It promotes reabsorption of calcium from the glomerular filtrate

B. It stimulates renal synthesis of 1,25 dihydroxyvitamin D

C. It shares biological activity with PTH-related protein (PTHrP)

D. It acts on the gut to increase calcium absorption

D. It acts on the gut to increase calcium absorption

Which of the following is MOST often elevated in hypercalcemia associated with malignancy?

A. Parathyroid hormone-related protein (PTHrP)

B. Parathyroid-derived PTH

C. Ectopic PTH

D. Calcitonin

A. Parathyroid hormone-related protein (PTHrP)

A clinical condition associated with chronic hyperparathyroidism is:

A. Seizure disorder

B. Vitamin D malabsorption

C. Hypernatremia

D. Osteoporosis and pathologic fracture

D. Osteoporosis and pathologic fracture

Hyperparathyroidism is MOST consistently associated with:

A. Metabolic alkalosis

B. Hypocalcemia

C. Hypocalciuria

D. Hypophosphatemia

D. Hypophosphatemia

The BEST method of analysis for serum PTH involves using antibodies that detect:

A. The amino-terminal fragment of PTH

B. The carboxyl-terminal end of PTH

C. Both the amino-terminal fragment and intact PTH

D. All fragments of PTH as well as intact hormone

C. Both the amino-terminal fragment and intact PTH

Which of the following hormone is often decreased by approximately 25% in the serum of pregnant women who have a fetus with Down syndrome?

A. Unconjugated estriol (LE3)

B. Human chorionic gonadotropin (hCG)

C. Progesterone

D. Conjugated estradiol (E2)

A. Unconjugated estriol (LE3)

Which of the following is secreted by the placenta and used for the early detection of pregnancy?

A. Follicle-stimulating hormone (FSH)

B. Human chorionic gonadotropin (hCG)

C. Luteinizing hormone (LH)

D. Progesterone

B. Human chorionic gonadotropin (hCG)

Which statement regarding maternal hormones during pregnancy is accurate?

A. Progesterone levels decline throughout gestation

B. Estrogen levels increase throughout gestation

C. hCG levels increase throughout gestation

D. CG levels remain stable throughout gestation

B. Estrogen levels increase throughout gestation

What factor causes the endometrium NOT to be sloughed or lost when a woman becomes pregnant?

A. The decrease in estrogen levels

B. The decrease in progesterone levels

C. The increase in FSH levels

D. hCG (human chorionic gonadotropin) produced by the trophoblasts of the conceptus

D. hCG (human chorionic gonadotropin) produced by the trophoblasts of the conceptus

Refer to the following graph:

increase months 1 and 2

slight decrease months 3 and 4

slight increase months 5-8

The hCG levels shown in the above graph most probably represent:

A. Hydatidiform mole following miscarriage at 4 months

B. Normal pregnancy

C. Development of hydatidiform mole

D. Miscarriage at 2 months with retained placenta

B. Normal pregnancy

Which of the following is NOT a common metabolic/physiological change that occurs in pregnant women?

A. Glucose sparing

B. Increased urine production

C. Lower blood pressure

D. Hypermetabolism

C. Lower blood pressure

Which statement is WRONG regarding hCG?

A. hCG is produced by the placenta

B. hCG stimulates the anterior pituitary gland

C. hCG stimulates the corpus luteum

D. hCG helps maintain estrogen and progesterone levels in the blood

B. hCG stimulates the anterior pituitary gland

During late pregnancy, the form of estrogen measured in urine is MOSTLY:

A. Estradiol

B. Estriol

C. Estrone

D. Pregnanediol

B. Estriol

TSH, LH and FSH share a common alpha peptide chain with which of the following hormones:

A. Growth hormone

B. Prolactin

C. Human chorionic gonadotropin (hCG)

D. Gonadotropin releasing hormone (GnRH)

C. Human chorionic gonadotropin (hCG)

The presence of a fetal neural tube disorder may be detected by:

A. Increased maternal serum alpha fetoprotein

B. Increased amniotic bilirubin

C. Decreased amniotic fluid phosphatidyl glycerol

D. Decreased maternal serum acetylcholinesterase

A. Increased maternal serum alpha fetoprotein

When performing marker screening tests for Down syndrome, why are results expressed in multiples of the median (MoM) rather than concentration?

A. Concentration is not normally distributed

B. Some tests cannot be reported in mass units

C. MoM normalizes for gestational age

D. Mean cannot be determined accurately for these analytes

C. MoM normalizes for gestational age

Which of the following statements accurately describes CG levels in pregnancy?

A. Levels of CG rise throughout pregnancy

B. In ectopic pregnancy, serum CG doubling time is below expected levels

C. Molar pregnancies are associated with lower levels than expected for the time of gestation

D. hCG returns to nonpregnant levels within 2 days following delivery, stillbirth, or abortion

B. In ectopic pregnancy, serum CG doubling time is below expected levels

Which of the following statements regarding the L/S

(Lecithin/Sphingomyelin) ratio is true?

A. A ratio of 2:1 or greater usually indicates adequate pulmonary surfactant to prevent respiratory distress syndrome (RDS)

B. A ratio of 1.5:1 indicates fetal lung maturity in pregnancies

associated with diabetes mellitus

C. Sphigomyelin levels increase during the third trimester, causing the L/S ratio to fall slightly during the last 2 weeks of gestation

D. A phosphatidy|glycerol (PG) spot indicates the presence of meconium in the amniotic fluid

A. A ratio of 2:1 or greater usually indicates adequate pulmonary surfactant to prevent respiratory distress syndrome (RDS)

The presence of phosphatidyl glycerol in amniotic fluid fetal lung maturity tests must be confirmed when:

A. Hemolytic disease of the newborn is present

B. Amniotic fluid is contaminated by hemoglobin

C. Neural tube disorder is suspected

D. The mother has gestational diabetes

D. The mother has gestational diabetes

Pulmonary maturity for the fetus is characterized by:

A. Increases in phosphatidyl glycerol and lecithin, while sphinomyelin is constant

B. Decreases in phosphatidyl glycerol and lecithin, while sphinomyelin is constant

C. Increases in phosphatidyl glycerol and lecithin, while sphinomyelin is decreases

D. Decreases in phosphatidyl glycerol and lecithin, while sphinomyelin is increases

A. Increases in phosphatidyl glycerol and lecithin, while sphinomyelin is constant

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 and progesterone

C. Human placental lactogen (PL)

D. Luteinizing hormone (LH)

D. Luteinizing hormone (LH)

Amniocentesis is performed on the woman whose last two pregnancies resulted in stillbirths due to hemolytic disease of the newborn. A screening test performed at the hospital is positive for bilirubin, and the specimen is sent to a reference laboratory for a bilirubin spectrophotometric scan. Physicians are concerned when the report comes back negative. What factor would be considered in evaluating this result?

A. Specimen was refrigerated

B. Specimen was centrifuged

C. Specimen was exposed to light

D. Specimen reached the reference lab within 30 minutes

C. Specimen was exposed to light

The primary source of circulating testosterone is the:

A. Anterior pituitary

B. Adrenal cortex

C. Hypothalamus

D. Testis

D. Testis

Secondary hormonal control of male reproductive function is located within the:

A. Anterior pituitary

B. Hypothalamus

C. Testis

D. Adrenal cortex

A. Anterior pituitary

The Sertoli cells of the testis synthesize:

A. Follicle-stimulating hormone

B. Inhibin

C. Testosterone

D. Lutenizing hormone

B. Inhibin

Testosterone concentration fluctuates in a circadian fashion and is HIGHEST:

A. 8 am

B. 12 noon

C. 8 pm

D. 11 pm

A. 8 am

The primary estrogen synthesized by the ovary and used to evaluate ovarian function is:

A. Estriol (E3)

B. Estrone (E1)

C. FSH

D. Estradiol (E2)

D. Estradiol (E2)

The inhibin hormones produced by the gonads inhibits the release of ____________ from the _________________.

A. FSH; posterior pituitary

B. LH; posterior pituitary

C. FSH: anterior pituitary

D. LH: anterior pituitary

C. FSH: anterior pituitary

Which of the following is the MOST potent androgen?

A. Androstenedione

B. Dehydroepiandrosterone

C. Testosterone

D. Dihydrotestosterone

D. Dihydrotestosterone

In males, pituitary luteinizing hormone (LH)

A. Induces Leydig cells in the testes to produce testosterone

B. Induces Sertoli cells to produce sperm

C. Stimulates ejaculation of semen

D. Has no known reproductive function

A. Induces Leydig cells in the testes to produce testosterone

Secretion of LH and FSH from the pituitary gland in males normally is suppressed by:

A. Estrogen

B. Prostate-specific antigen

C. Cortisol

D. Testosterone

D. Testosterone

The major difference between male and female sex hormone production is that:

A. LH has no apparent action in the male

B. Sex hormone production in the male is relatively constant

C. Estrogen is not produced in the male

D. In the male, GnRH does not cause the release of FSH

B. Sex hormone production in the male is relatively constant

A 30-year-old female with newly diagnosed polycystic ovarian syndrome is being counseled by her OB-GYN. The physician indicates that this condition OFTEN results in:

A. Ovarian cancer

B. Infertility

C. Early menopause

D. Pelvic inflammatory disease

B. Infertility

A 46-year-old female is in menopause. She has ovarian failure. Which of the following also occurs?

A. Decreased estrogen and progesterone, increased LH and FSH

B. Decreased estrogen and progesterone, normal LH and FSH

C. Decreased estrogen, testosterone, and androgen

D. Decreased estrogen, FSH, LH, and progesterone

A. Decreased estrogen and progesterone, increased LH and FSH

Sex hormones are secreted by _____________________________.

A. All endocrine tissues of the body

B. The inner layer of the adrenal cortex and the gonads

C. The gonads

D. The inner layer of the adrenal cortex

B. The inner layer of the adrenal cortex and the gonads

Which hormone is MOST closely involved with ovulation?

A. Prolactin

B. LH (luteinizing hormone)

C. FSH (follicle stimulating hormone)

D. Estrogen

B. LH (luteinizing hormone)

Which set of results is MOST likely in adult male with primary testicular failure?

A. Increased LH, FSH, and decreased testosterone

B. Decreased LH, FSH, and testosterone

C. Decreased testosterone, androstenedione, and FSH

D. Increased androstenedione, decreased testosterone, and normal FSH

A. Increased LH, FSH, and decreased testosterone

When pituitary adenoma is the cause of decreased estrogen production, an increase of which hormone is MOST frequently responsible?

A. Prolactin

B. FSH

C. LH

D. TSH

A. Prolactin

A female with severe excessive pubic and facial hair growth (hirsutism) should be tested for which of the following hormones?

A. Estrogen and progesterone

B. Chorionic gonadotropin

C. Growth hormone

D. Testosterone and dehydroepiandrosterone sulfate

D. Testosterone and dehydroepiandrosterone sulfate

In the testes the synthesis of androgen-binding protein or SHBG (Sex Hormone Binding Globulin) is stimulated by:

A. Inhibin and LH

B. FSH and testosterone

C. Estradiol and gonad releasing hormone

D. Progesterone and LH

B. FSH and testosterone

Which hormone is responsible for an increase in body temperature at the time of ovulation?

A. Progesterone

B. Estrogen

C. LH

D. FSH

A. Progesterone

Which of the following tests on amniotic fluid can be used to help detect an open neural tube defect?

A. AFP (alpha-fetoprotein)

B. AChE (Acetylcholinesterase)

C. L/S ratio

D. Both AChE and AFP

D. Both AChE and AFP

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.