Clinical Chemistry Review CLS 540

The principle method used to measure hormone levels in blood in most clinical laboratories is:

A. Gas chromatography

B. Thin layer chromatography

C. Electrophoresis

D. Immunoassay

D. Immunoassay

Which chemical classification of hormones does not utilize a second messenger system to produce the effect of a hormone?

A. Amino acid related

B. Polypeptide

C. Steroid

D. Protein

C. Steroid

Secretion of hormones by the adenohypohysis may be controlled by the circulating levels of hormones from the respective target gland, as well as hormones secreted by what tissue?

A. Posterior lobe of the pituitary gland

B. Intermediate lobe of the pituitary gland

C. Hypothalamus

D. Adrenal medulla

C. Hypothalamus

Which of the following hormones is stored in the neurohypophysis and involved in uterine contraction?

A. Corticotrophin-releasing hormone

B. Oxytocin

C. Thyroid-stimulating hormone

D. Growth hormone

B. Oxytocin

Where is antidiuretic hormone (ADH or vasopressin) synthesized?

A. Adrenal cortex

B. Adenohypophysis

C. Hypothalamus

D. Posterior pituitary

C. Hypothalamus

Which of the following hormones initiates its response by binding to cytoplasmic receptors?

A. Insulin

B. ACTH

C. Cortisol

D. Thyroxine

C. Cortisol

Which of the following functions as an inhibiting factor for growth hormone release?

A. Gonadotropin-releasing hormone

B. Growth hormone-releasing hormone

C. Dopamine

D. Somatostatin

D. Somatostatin

Activation of the sympathetic nervous system leads to the 'fight and flight' response. Which of these is NOT part of that process:

A. Vasodilatation in skeletal muscle

B. Sweating

C. Increased blood pressure

D. Increased gut motility

D. Increased gut motility

Which of the following hormones enters the target cells by passive diffusion?

A. Oxytocin

B. Prolactin

C. Thyrotropin-releasing hormone

D. Estrogen

D. Estrogen

A 50-year-old female patient underwent surgery to remove a pituitary tumor. During surgery, the pituitary stalk was severed. Secretion of which of the following hormones would increase?

A. PRL (Prolactin)

B. TSH (Thyroid Stimulating Hormone)

C. GH (Growth Hormone)

D. LH (Luteinizing Hormone)

A. PRL (Prolactin)

Antidiuretic hormone (ADH) release from the posterior pituitary is stimulated by:

A. Low blood pressure sensed by baroreceptors in the kidneys

B. High serum osmolarity sensed by osmoreceptors in the hypothalamus

C. Low osmolarity sensed by osmoreceptors in the kidneys

D. High concentration of potassium sensed by chemoreceptors in the carotid body

B. High serum osmolarity sensed by osmoreceptors in the hypothalamus

Common neurologic disturbances seen with pituitary adenomas are:

A. Comas

B. Visual disturbances

C. Confusional states

D. Breathing abnormalities

B. Visual disturbances

A 15-year-old female presents with breast discharge, dysmenorrhea, and excessive excitability. Tests reveal that all her pituitary hormones are elevated. The most likely cause is:

A. A pituitary adenoma

B. Hypothalamic hyposecretion

C. Hypothalamic inflammation

D. A neurohypophyseal tumor

A. A pituitary adenoma

A 22-year-old male is admitted to the intensive care unit with a closed head injury sustained in a motorcycle accident. The injury has caused severe damage to the posterior pituitary. Which of the following complications should be anticipated?

A. Dilutional hyponatremia

B. Dehydration from polyuria

C. Cardiac arrest from hyperkalemia

D. Metabolic acidosis

B. Dehydration from polyuria

A 54year-old patient with pulmonary tuberculosis (lung infection) is evaluated for syndrome of inappropriate ADH secretion (SIADH). Which of the following clinical manifestations would be expected from this patient?

A. Peripheral edema

B. Tachycardia

C. Low blood pressure

D. Concentrated urine

D. Concentrated urine

Hormone levels in the body are kept from rising too high primarily by a(an):

A. Active kidney excretion of hormones

B. Enzymatic degradation of hormones

C Positive feedback mechanism

D. Negative feedback mechanism

D. Negative feedback mechanism

Normally secretion of growth hormone is suppressed by all of the following except:

A. Hypoglycemia

B. Somatostatin

C. IGF-I

D. Growth hormone

A. Hypoglycemia

When insulin binds to its receptors on muscle cells, an increase in glucose uptake by the muscle cells occurs. This is an example of ___________________ effect by the hormone.

A. Pharmacologic

B. Permissive

C. Synergistic

D. Direct

D. Direct

A patient has signs and symptoms suggestive of acromegaly. The diagnosis would be confirmed if the patient had which of the following?

A. An elevated serum phosphate concentration

B. A decreased serum growth hormone releasing factor concentration

C. No decrease in serum growth hormone concentration 90 minutes after oral glucose administration

D. An increase serum somatostatin concentration

C. No decrease in serum growth hormone concentration 90 minutes after oral glucose administration

The adrenal cortex releases:

A. Corticosteroids

B. Mineralosteroids

C. Androgens

D. All of the listed

D. All of the listed

The rate-limiting step in the formation of adrenal cortex steroids is the synthesis of:

A. Corticosterone

B. Cortisol

C. Pregnenolone

D. Progesterone

C. Pregnenolone

Pituitary secretion of ACTH is inhibited by elevated circulating levels of:

A. Aldosterone

B. Cortisol

C. Estradiol

D. Progesterone

B. Cortisol

The most common form (95%) of congenital adrenal hyperplasia is 21-hydroxylase deficiency, which can be detected by elevated plasma levels of:

A. Cortisol

B. Aldosterone

C. 17-OH-progesterone

D. 11-deoxycortisol

C. 17-OH-progesterone

How is primary hypocortisolism (Addison disease) differentiated from secondary hypocortisolism (of pituitary origin)?

A. Adrenal corticotropic hormone (ACTH) is decreased in primary and elevated in secondary

B. Adrenal corticotropic hormone (ACTH) is increased in primary and decreased in secondary

C. Low aldosterone and hypoglycermia present with secondary hypocortisolism

D. Normal cortisol levels and blood pressure with primary

hypocortisolism

B. Adrenal corticotropic hormone (ACTH) is increased in primary and decreased in secondary

Which of the following sample collection would give an accurate assessment of potential excess cortisol production (hypercortisolism)?

A. Collect a plasma sample as baseline, and another 1-hour after administration of metyrapone

B. Collect a plasma sample at 8 am only

C. Collect a 24-hour urine free cortisol

D. Collect a plasma sample at 8 am and at 8 am the next day

C. Collect a 24-hour urine free cortisol

A person having an abnormally low cortisol baseline is given ACTH. A subsequent cortisol taken after the ACTH shows no change in the level. The most probable diagnosis is:

A. Cushing disease

B. Addison disease

C. Adrenocortical tumor

D. Hypopituitarism

B. Addison disease

Aldosterone is released by the adrenal cortex upon stimulation by:

A Renin

B. Angiotensinogen

C. Angiotensin I

D. Angiotensin II

D. Angiotensin II

As a screening test for Cushing 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 am; 2 pm

B. 8 am; 8 pm

C. 12 noon; 6 pm

D. 12 noon; 12 midnight

B. 8 am; 8 pm

The innermost layer of the adrenal cortex is called the:

A. Zona reticularis

B. Zona glomerulosa

C. Zona fasciculate

D. Zona medulla

A. Zona reticularis

The major site for steroid metabolism is the:

A. Kidney

B. Gl tract

C. Spleen

D. Liver

D. Liver

Which of the following steroid molecules has a more powerful role in electrolyte metabolism and homeostasis of sodium in the blood?

A. 11-deoxycorticosterone

B. 11-deoxycortisol

C. Aldosterone

D. Androstenedione

C. Aldosterone

A 35-year-old female took corticosteroid therapy for several months. Which of the following would be expected?

A. Renal toxicity

B. Episodes of hypoglycemia

C. Hirsutism

D. Type 2 diabetes mellitus-like

D. Type 2 diabetes mellitus-like

A 50-year-old male with one kidney had to undergo surgery for an adrenal tumor. His zona glomerulosa was largely removed during the surgery. Which of the following would most likely occur?

A. Hypernatremia

B. Dehydration

C. Alkalosis

D. Hypokalemia

B. Dehydration

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:

Urine free cortisol = increased

Serum cortisol (8 am) = 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. Addison disease

D. Adrenocortical carcinoma

D. Adrenocortical carcinoma

A 50-year-old female presents with light-headedness and overall abnormal feelings. CT scan reveals an adrenal cortical tumor. Lab tests reveal that the tumor is hormone-secreting. Which of the following would be expected?

A. Increased renin levels

B. Hypotension

C. Hypokalemia

D. Hyponatremia

C. Hypokalemia

A 49-year-old female is diagnosed with hypercortisolism. An increase in which of the following would be expected?

A. Protein catabolism and liver gluconeogenesis

B. Fat storage and glucose utilization

C. Production and secretion of adrenal hormones

D. Fat, protein, and carbohydrate anabolism

A. Protein catabolism and liver gluconeogenesis

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 clinical finding that is consistent with a diagnosis of adrenocortical insufficiency is:

A. Hypokalemia

B. Hypoglycemia

C. Hypertension

D. Moon face

B. Hypoglycemia

A patient has a history of fungal infection. He comes to his physician of weakness and fatigue. His laboratory results show a decreased glucose, increased potassium, decreased total carbon dioxide, slightly increased BUN, and a decreased cortisol level. The results would lead to suspect that the patient has:

A. Addison's disease

B. Cushing syndrome

C. Intermittent adrenal hyperplasia

D. Hyperaldosteronism

A. Addison's disease

When blood pressure decreases, the release of renin from the initiates the mechanism.

A. Lung; renin-cortisol

B. Kidney; Embden-Myer glucose

C. Liver; renin-angiotensin

D. Kidney; angiotensinogen-aldosterone

D. Kidney; angiotensinogen-aldosterone

Most steroid hormones are carried by a binding protein to the site of action because they are insoluble in aqueous environments. In the case of cortisol, a steroid hormone, the binding protein for transport is:

A. Albumin

B. CBG

C. TBG

D. SHBG

B. CBG

Which of the following statements is NOT correct about laboratory analysis of 5-HIAA?

A. Need a 24-hr urine sample to quantify

B. Brown polypropylene bottle needed for collection

C. No dietary restrictions are necessary during collection

D. Sodium metabisulfite and EDTA are needed as preservatives

C. No dietary restrictions are necessary during collection

Which metabolite is MOST often increased in carcinoid tumors of the intestine?

A. Homovanillic acid (HVA)

B. 3-Methoxydopamine

C. 3-Methoxy-4-hydroxyphenylglycol (MHPG)

D. 5-hydroxyindolacetic acid (5-HIAA)

D. 5-hydroxyindolacetic acid (5-HIAA)

A 15-year-old male took an illicit drug that acts by directly inhibiting phenylethanolamineN-methyltransferase(PNMT). Secretion of which of the following hormones would be inhibited?

A. Dopamine

B. Epinephrine

C. Norepinephrine

D. Tyrosine

B. Epinephrine

A 4-year-old female presents with palpable abdominal mass, pallor, and petechia. Based on family history, clinical findings, and the patient 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. Increase urinary homovanillic acid (HVA)

D. Decreased urinary vanillylmandelic acid (VMA)

D. Decreased urinary vanillylmandelic acid (VMA)

The urinary excretion product measured as an indicator of epinephrine production is:

A. Dopamine

B. Dihydroxyphenylalanine

C. Homevandelic acid

D. Vanillylmandelic acid (VMA)

D. Vanillylmandelic acid (VMA)

Pheochromocytoma is a benign or malignant tumor arising from:

A. Bile caniculi

B. Trophoblastic cells

C. Neurochromaffin cells in the adrenal medulla

D. Follicular cells of the thyroid

C. Neurochromaffin cells in the adrenal medulla

Metabolites of adrenal medulla hormones include:

A. Methoxytryramine dihydroxyphenyl acetic acid

B. Vanillymandelic acid (VMA)

C. Homovanillic acid (HVA)

D. All of the listed

D. All of the listed

Which of the following classes of compounds is derived from tyrosine and includes epinephrine, norepinephrine, and dopamine?

A. Steroids

B. Androgens

C. Catecholamines

D. Estrogens

C. Catecholamines

The adrenal medulla secrets which of the following in the GREATEST quantity?

A. Metanephrine

B. Dopamine

C. Norepinephrine

D. Epinephrine

D. Epinephrine

The following instructions were given to a patient prior to the collection of a 24-hour urine specimen: The urine must be maintained at a pH of 2 in a dark bottle. The patient should not eat/drink coffee, chocolate, bananas, oranges, aspirin, Aldomet (methyldopa, a-adrenergic agonist for lowering blood pressure) for a period of time before or during the collection. These instructions are consistent with obtaining a urine sample for the determination of:

A. Dopamine

B. Homovanillic acid (HVA)

C. Norepinephrine

D. Vanillylmandelic acid (VMA)

D. Vanillylmandelic acid (VMA)

Dopamine and norepinephrine are naturally occurring catecholamines that function to (as):

A. Affect metabolic processes

B. Neurotransmitters

C. Catabolize enzymes

D. Influencer on the vascular system

B. Neurotransmitters