ATI LPN
PN Learning System Medical Surgical Endocrine Practice Quiz Questions
Question 1 of 5
A study of renal disease identifies patients with greater than 3.5 g of protein in a 24-hour urine collection, but no RBCs or WBCs. Dysfunction involving which of the following cells is most likely to be responsible for proteinuria?
Correct Answer: D
Rationale: The podocytes (visceral epithelial cells) of the glomerulus form a filtration barrier that depends upon both the anionic charge as well as slit diaphragms. Injuries that cause effacement, retraction, detachment, and vacuolization allow protein, principally albumin, to escape into Bowman space. Podocytes have limited capacity for regeneration and repair. The loss of 3.5 g/day of protein defines nephrotic syndrome. About a sixth of filtration occurs through the mesangium. The remaining listed options do not participate in this epithelial protein filtration barrier.
Question 2 of 5
A 47-year-old woman noticed a lump in her neck 1 week ago. On physical examination, there is a 2-cm nodule in the right lobe of the thyroid gland. A fine-needle aspiration biopsy is performed, and microscopic examination of the specimen shows cells consistent with a follicular neoplasm. She undergoes a subtotal thyroidectomy. Which of the following laboratory tests should be performed on this patient in the immediate postoperative period?
Correct Answer: C
Rationale: Inadvertent removal of or damage to the parathyroid glands during thyroid surgery can cause hypocalcemia secondary to hypoparathyroidism. This is the most common cause of hypoparathyroidism. Individuals with hypocalcemia exhibit neuromuscular irritability, carpopedal spasm, and sometimes seizures. Antithyroglobulin antibody levels are of no use in diagnosing surgical diseases of the thyroid. Calcitonin quantitative is not a useful measure to determine the status of calcium metabolism.
Question 3 of 5
A 39-year-old man has had headache, weakness, and a 5-kg weight gain over the past 3 months. He has experienced mental depression during the same period. On physical examination, his face is puffy. His temperature is 36.9°C and blood pressure is 160/75 mm Hg. He has cutaneous striae over the lower abdomen and ecchymoses scattered over the extremities. A radiograph of the spine shows a compressed fracture of T11. Laboratory findings show fasting plasma glucose level of 200 mg/dL, serum Na+ of 150 mmol/L, and serum K+ of 3.1 mmol/L. The plasma cortisol level is 38 μg/dL at 8:00 am and 37 μg/dL at 6:00 pm. Administration of low and high doses of dexamethasone fails to suppress the plasma cortisol level and excretion of urinary 17-hydroxycorticosteroids. The plasma corticotropin level is 0.8 pg/mL. Which of the following lesions is most likely to be present in this man?
Correct Answer: B
Rationale: The clinical and laboratory features of this case point to Cushing syndrome. The dexamethasone suppression test is used to localize the source of excess cortisol. When low-dose and high-dose dexamethasone trials fail to suppress cortisol secretion, a pituitary corticotropin-secreting adenoma as the source of excess glucocorticoids is unlikely. The choice is an ectopic source of corticotropin, such as a lung cancer, or a tumor of the adrenal cortex that is secreting glucocorticoids. The plasma corticotropin level distinguishes between these two possibilities. Corticotropin levels are high if there is an ectopic source, whereas glucocorticoid secretion from an adrenal neoplasm suppresses corticotropin production by the pituitary, leading to atrophy of the contralateral adrenal cortex.
Question 4 of 5
Which of the following statements regarding hormones is incorrect?
Correct Answer: A
Rationale: Hormones act via bloodstream, not synapses (neurotransmitters do); others are true: receptor specificity, gene expression, second messengers.
Question 5 of 5
Adonis arrives at the gym and spots a dumbbell he wants to use. When attempting to lift the weight, his biceps brachii contract, but the weight is not moved because it is too heavy. This is called?
Correct Answer: A
Rationale: Isometric contraction: muscle tenses without shortening, as load exceeds force.