468. A 22-year-old woman presents with a recurrent vaginal candidiasis that is refractory to nystatin treatment. Diabetes screening shows elevated fasting blood glucose, and the patient is started on 25 U of insulin per day. Which aspect of glucose transport is enhanced by insulin?
a. Transport across the tubular epithelium of the kidney
b. Transport against a concentration gradient
c. Transport into adipocytes
d. Transport into the brain
e. Transport through the intestinal mucosa
469. A 24-year-old pregnant woman and her 3-year-old child are seen in a medical mission clinic in Sudan. The child is short in stature, has a potbelly and enlarged protruding tongue, and is developmentally delayed. Iodine is prescribed for mother and child, with the hope of preventing mental retardation in the developing fetus. Iodides are stored in the thyroid follicles mainly in the form of which of the following?
c. Thyroid peroxidase
470. A 15-year-old girl presents with loss of the outer one-third of her eyebrows. Physical examination demonstrates slight enlargement of the thyroid gland and delayed relaxation phase of deep tendon reflexes. Blood work shows an elevation in creatine phosphokinase and TSH. Thyroid hormone therapy is ordered. Physiologically active thyroxine exists in which of the following forms?
a. As a glucuronide
b. Bound to albumin
c. Bound to globulin
d. Bound to prealbumin
471. A 35-year-old woman presents to her primary care physician with weakness and fatigue for the past 6 months. Before this current episode, she used to be a very active runner, but has not had the strength or energy to work out in the last few weeks. Despite this decrease in exercise, she has lost 10 lb over this time, and also reports a decreased appetite. She has also had two presyncopal episodes in the last 2 weeks and has noticed that her skin appears darker than usual. Laboratory tests show:
Serum ACTH: >100 pg/mL
ACTH stimulation test: Cortisol 10 μg/dL
What is the best description of the patient’s fluid and osmolarity status?
a. Hyposmotic volume contraction
b. Hyposmotic volume expansion
c. Hyperosmotic volume contraction
d. Hyperosmotic volume expansion
e. Isosmotic volume contraction
472. A 3-year-old patient with DiGeorge congenital thymic aplasia presents with a seizure. An elevated serum phosphorus and low serum calcium confirm a hypoparathyroid state. Plasma levels of calcium can be increased most rapidly by the direct action of PTH on which of the following?
d. Skeletal musculature
e. Thyroid gland
473. A 20-year-old man presents with increasing daytime somnolence. A 24-hour sleep study showing a sudden onset of rapid eye movement (REM) sleep without previous slow-wave sleep confirms a diagnosis of narcolepsy. REM sleep decreases the secretion of growth hormone. The physiological secretion of growth hormone is increased by which of the following?
a. Free fatty acids
b. Growth hormone
474. A 50-year-old alcoholic man presents with cirrhotic liver disease and chronic pancreatitis. He has been experiencing nausea for the past several days, and not eating. As a result of an elevation in his blood glucagon levels, which of the following will occur?
a. Inhibition of adenylate cyclase
b. Inhibition of insulin secretion
c. Inhibition of phospholipase C
d. Stimulation of gluconeogenesis in the liver
e. Stimulation of glycogenolysis in muscle
475. A patient with hyperkalemic renal failure is given an infusion of glucose and insulin. The actions of insulin include which of the following?
a. Converting glycogen to glucose
b. Enhancing potassium entry into cells
c. Increasing plasma amino acid concentration
d. Reducing urine formation
e. Stimulating gluconeogenesis
476. A 47-year-old woman with an anterior pituitary tumor presents with poor wound healing and hypertension. The endogenous secretion of ACTH is correctly described in which of the following statements?
a. It is decreased during periods of stress.
b. It is inhibited by aldosterone.
c. It is stimulated by glucocorticoids.
d. It is stimulated by epinephrine.
e. It shows a circadian rhythm in humans.
477. A patient with tuberculosis becomes confused and complains of muscle cramps and nausea. Laboratory results show a plasma sodium concentration of 125 mEq/L, serum osmolarity of 200 mOsm/kg, urine osmolarity of 1,500 mOsm/kg, urine sodium of 400 mEq/d, and a normal blood volume. These clinical findings are consistent with which of the following?
a. Decreased secretion of aldosterone
b. Decreased secretion of ADH
c. Increased secretion of aldosterone
d. Increased secretion of ADH
e. Increased secretion of atrial natriuretic peptide
478. A 65-year-old woman with metastatic small cell lung cancer presents to the emergency department with nausea, vomiting, and tachycardia. She is diagnosed as having Addison disease. Which of the following is most consistent with a patient in this condition?
479. An abdominal computed tomography (CT) in a 50-year-old patient with Conn’s syndrome (primary hyperaldosteronism) shows multiple small adrenocortical masses. Which of the following clinical findings are most likely present?
a. Decreased extracellular fluid volume
d. Increased concentrating ability of the kidney
e. Increased hematocrit
480. A 75-year-old woman with primary hyperparathyroidism presents at her physician’s office with dehydration and malaise. Which of the following plasma levels are most likely to be decreased?
481. A 29-year-old man complains of weight gain, decreased energy, dry skin, and brittle hair for the past 6 months. He was diagnosed with hypothyroidism and started on synthetic thyroid hormone. A decrease in which of the following laboratory values would be expected as result of starting treatment?
a. Free T4
b. Plasma cholesterol
c. Plasma iron
e. Vitamin A
482. A 37-year-old woman presents with exophthalmus and an enlarged thyroid gland. The levels of free thyroxine in her blood are elevated. Other clinical findings of Graves’ disease include which of the following?
c. Decreased sweating
d. Increased basal metabolic rate
e. Increased weight gain
483. A 20-year-old man with diabetes forgets to take his insulin prior to the start of the National Collegiate Athletic Association (NCAA) swimming championships. Insulin-independent glucose uptake occurs in which of the following sites?
a. Adipose tissue
c. Cardiac muscle
d. Skeletal muscle
484. A 46-year-old woman on lithium therapy for her bipolar disorder presents with complaints of weakness, arthralgia, and constipation. Blood work reveals hypercholesterolemia, increased levels of TSH, and decreased free T4 levels. Which of the following is also likely to be associated with her hypothyroid state?
a. Decreased body mass index
b. Heat intolerance
c. Increased metabolic rate
485. A multisystem trauma patient develops hyperpyrexia, severe tachycardia, and high-output congestive heart failure with volume depletion, consistent with thyroid storm. Which of the following is the most appropriate treatment for the exaggerated hyperthyroidism?
a. Aspirin to treat fever
b. β-Adrenergic antagonist therapy to block sympathomimetic symptoms
c. Iodine followed by propylthiouracil to block release and synthesis of thyroid hormone
d. Oral hydration to correct volume depletion
e. T3 administration to induce negative feedback inhibition of T4
486. A 13-year-old boy presents for short stature. He was growing appropriately; however, 2 years ago, his primary pediatrician noticed he dropped two percentiles on his growth chart. The patient reports he is much smaller than his friends and has not noticed any pubertal changes such as enlargement of testes or development of axillary or pubic hair. What laboratory test abnormality would you expect to see?
a. Decreased ACTH
b. Decreased IGF-I
c. Increased gonadotropins
d. Increased growth hormone
e. Increased thyroxine
487. A patient presents with Whipple’s triad, including plasma glucose <60 mg/dL, symptomatic hypoglycemia, and improvement of symptoms with administration of glucose. CT of the abdomen is suggestive of islet cell carcinoma. Which of the following best describes the islets of Langerhans?
a. They are found primarily in the head of the pancreas.
b. They contain six distinct endocrine cell types.
c. They constitute approximately 30% of the pancreatic weight.
d. They have a meager blood supply.
e. They secrete insulin and glucagon.
488. A 59-year-old man is brought to his physician’s office by his wife. She reports that he has been weak, nauseated, and urinates frequently. She has also noticed a fruity odor on her husband’s breath. A urine sample is strongly positive for ketones and the finger-stick glucose is high, leading to a presumptive diagnosis of diabetes. As a result of insulin deficiency, which of the following will most likely occur?
a. Decreased fatty acid release from adipose tissue
b. Decreased intracellular α-glycerophosphate in liver and fat cells
c. Enhanced glucose uptake and use except by brain tissue
d. Increased cellular uptake of glucose
e. Indirect depression of glucose utilization due to excess fatty acids in the blood
489. A 24-year-old woman presents with a slightly elevated blood pressure. She has high plasma levels of total T4, cortisol, and renin activity, but no symptoms or signs of thyrotoxicosis or Cushing’s syndrome. Which of the following is the most likely explanation?
a. She has an adrenocortical tumor.
b. She has been subjected to chronic stress.
c. She has been treated with ACTH and TSH.
d. She has been treated with T3 and cortisol.
e. She is in the third trimester of pregnancy.
490. A 13-year-old girl presents for her annual sports physical exam. Her height is measured at 50 in (>3 SD below the mean for her age), and the history suggests that the girl may be suffering from anorexia nervosa. Which of the following about growth and development is most likely?
a. Growth hormone activates the JAK2-STAT pathway.
b. Linear growth ceases earlier in boys than in girls.
c. Serum IGF-I levels decrease throughout childhood.
d. Growth hormone is essential for prenatal linear growth.
e. Normal growth during puberty is independent of thyroid function.
491. A 57-year-old postmenopausal woman takes calcium and vitamin D supplements daily to prevent osteoporosis. Which of the following best describes vitamin D?
a. 1,25 (OH)2-vitamin D production increases when PTH secretion decreases.
b. It is a water-soluble vitamin.
c. It is converted to 1,25 (OH)2-vitamin D in the liver.
d. The physiologically active form of vitamin D is 1,25 (OH)2-vitamin D.
e. Vitamin D deficiency is seen in areas with high sun exposure.
492. A 22-year-old woman with insulin-dependent diabetes mellitus presents to the emergency department with nausea, vomiting, and a blood glucose of 600. She is found to have diabetic ketoacidosis (DKA). Which of the following is true regarding patients with DKA?
a. Intracellular potassium levels are increased.
b. Intravenous fluids correct the acidosis.
c. Respiratory rate decreases.
d. Serum potassium levels are decreased.
e. Serum potassium levels are increased.
493. A 34-year-old patient with chronic asthma is started glucocorticoid therapy. The treatment may result in bone loss because glucocorticoids do which of the following?
a. Increase calcium absorption from the gastrointestinal tract
b. Increase osteoblast growth
c. Inhibit bone formation
d. Inhibit bone resorption
e. Suppress vitamin D activation
494. Radiation treatment for a pituitary tumor in an 8-year-old boy results in complete loss of pituitary function. As a result, the child is likely to experience which of the following symptoms?
a. Accelerated growth spurts
d. Increased responsiveness to stress
e. Sexual precocity
495. A 36-year-old male computer programmer works for a company that has just been acquired in a corporate takeover. He experiences symptoms of tachycardia, palpitations, and an irregular heartbeat, particularly at night. His plasma catecholamine levels are found to be increased, which may result from which of the following?
a. Changing from the standing to the supine position
b. An increase in blood glucose
c. An increase in blood pressure
d. An increase in blood volume
e. An increase in plasma cortisol
496. An 18-year-old man with hemophilia A suffered multiple internal injuries from a motorcycle accident. He is now presenting with dizziness, abdominal pain, dark patches on his elbows and knees, and cravings for chips and french fries. He is referred to an endocrinologist who makes the diagnosis of Addison’s disease, and prescribes cortisol. Cortisol administration to a patient with adrenal insufficiency will result in which of the following?
a. Enhanced wound healing
b. Increased ACTH secretion
c. Increased corticotropin-releasing hormone (CRH) secretion
d. Increased gluconeogenesis
e. Increased insulin sensitivity in muscle
497. An 80-year-old man reports increasing dyspnea, which worsens with exertion. The cardiologist orders an echocardiogram, brain natriuretic peptide, and atrial natriuretic peptide (ANP) to evaluate possible congestive heart failure. Which of the following is most likely with ANP?
a. ANP acts only on the distal nephron to increase urine flow.
b. ANP constricts afferent renal arterioles.
c. ANP enhances ADH secretion.
d. ANP secretion increases when central venous pressure increases.
e. ANP secretion is stimulated by hyponatremia.
498. A patient with multiple endocrine neoplasia type I (MEN I) and acromegaly is found to have a deletion of the 11q13 region of chromosome 11, a suppressor gene for growth hormone. Growth hormone excess results in which of the following?
a. Decreased gluconeogenesis
b. Decreased lipolysis
c. Decreased protein synthesis
e. Insulin resistance
499. Sulfonylurea treatment in a 53-year-old type 2 diabetic patient causes a fall in the patient’s plasma glucose concentration to 45 mg/dL. Which of the following is a sign and symptom of hypoglycemia?
b. Dry skin
d. Loss of fine motor skills
500. A 29-year-old woman presents with paroxysmal episodes of headaches, anxiety, and palpitations. The physician suspects an anxiety disorder, but orders laboratory studies to rule out underlying disease. The laboratory findings of hypercalcemia and elevated urinary catecholamines suggest the possibility of MEN II. Which of the following is the hallmark of pheochromocytoma?
a. Dry skin
e. Weight gain