CELLULAR INJURY AND ADAPTATION MCQs

Question 1

On a routine visit to the physician, an otherwise healthy 51-year-old man has a blood pressure of 150/95 mm Hg. If his hypertension remains untreated for years, which of the following cellular alterations would most likely be seen in his myocardium?

Accepted Answer

Hypertrophy ANSWER: E — The pressure load on the left ventricle results in an increase in myofilaments in the existing myofibers. The result of continued stress from hypertension is eventual heart failure with decreased contractility, but the cells do not decrease in size. ---

Question 2

A 38-year-old woman experienced severe abdominal pain with hypotension and shock that led to her death within 36 hours after the onset of the pain. The mesentery shows focal, chalky white deposits. Which of the following events has most likely occurred?

Accepted Answer

Acute pancreatitis ANSWER: E — The focal, chalky white deposits are areas of fat necrosis resulting from the release of pancreatic lipases in a patient with acute pancreatitis. ---

Question 3

A 68-year-old woman suddenly lost consciousness; on awakening 1 hour later, she could not speak or move her right arm and leg. Two months later, a head CT scan showed a large cystic area in the left parietal lobe. Which of the following pathologic processes has most likely occurred in the brain?

Accepted Answer

Liquefactive necrosis — The high lipid content of central nervous system tissues results in liquefactive necrosis as a consequence of ischemic injury, as in this case of a "stroke." ---

Question 4

A 30-year-old man sustains a left femoral fracture in a skiing accident, and his leg is placed in a plaster cast. After the leg has been immobilized for several weeks, the diameter of the left calf has decreased. This change is most likely to result from which of the following alterations in the calf muscles?

Accepted Answer

Atrophy — Reduced workload causes shrinkage of cell size because of loss of cell substance, a process called atrophy. Aplasia refers to lack of embryonic development; hypoplasia describes poor or subnormal development. ---

Question 5

An experiment analyzes cells for enzyme activity associated with sustained cellular proliferation. Which of the following cells is most likely to have the highest telomerase activity?

Accepted Answer

Germ cells — Germ cells have the highest telomerase activity, and the telomere length can be stabilized in these cells. This allows testicular germ cells to retain the ability to divide throughout life. ---

Question 6

On day 28 of her menstrual cycle, a 23-year-old woman experiences onset of menstrual bleeding that lasts for 6 days. She has had regular cycles for many years. Which of the following processes is most likely occurring in the endometrium just before the onset of bleeding?

Accepted Answer

Apoptosis — The onset of menstruation is an example of orderly, programmed cell death (apoptosis) through hormonal stimuli. The endometrium breaks down, sloughs off, and then regenerates. ---

Question 7

After the birth of her first child, a 19-year-old woman breastfed the infant for about 1 year. Which of the following processes that occurred in the breast during pregnancy allowed her to breastfeed the infant?

Accepted Answer

Lobular hyperplasia — Lobules increase under hormonal influence (mainly progesterone) to provide for normal lactation. The breast stroma plays no role in lactation and may increase with pathologic processes. ---

Question 8

A 44-year-old man has a history of poorly controlled diabetes mellitus leading to coronary artery disease. He now has decreasing cardiac output. An increase in which of the following substances in his blood is most indicative of reversible cell injury from decreased perfusion of multiple organs and tissues?

Accepted Answer

Lactic acid — Decreased tissue perfusion leads to hypoxemia and depletion of ATP when cell metabolism shifts from aerobic to anaerobic glycolysis, resulting in depletion of glycogen stores and increased production and accumulation of lactic acid, reducing intracellular pH. ---

Question 9

The nonpregnant uterus of a 20-year-old woman measures 7 × 4 × 3 cm. The woman becomes pregnant and just before delivery of a term infant, the uterus measures 34 × 18 × 12 cm. Which of the following cellular processes has contributed most to the increase in uterine size?

Accepted Answer

Myometrial smooth muscle hypertrophy — The increase in uterine size is primarily the result of an increase in myometrial smooth muscle cell size. The endometrium also increases in size, but it remains as a lining to the muscular wall and does not contribute as much to the change in size. ---

Question 10

A 28-year-old man with cystic fibrosis undergoes genetic testing that reveals a ΔF508 mutation in the CFTR gene. This mutation results in production of a misfolded protein that is retained in which of the following cellular locations?

Accepted Answer

Endoplasmic reticulum — The ΔF508 mutation produces a misfolded CFTR protein that is retained in the endoplasmic reticulum and degraded rather than being transported to the cell membrane. This is analogous to α1-antitrypsin deficiency where misfolded proteins accumulate in the ER ---

Question 11

A 62-year-old man with chronic obstructive pulmonary disease develops cor pulmonale with right ventricular hypertrophy. Which of the following mechanisms best explains the adaptive change in the right ventricle?

Accepted Answer

Increased size of existing myocardial cells — Cardiac myocytes are permanent cells that cannot divide. Hypertrophy results from increased workload (pressure overload from pulmonary hypertension) causing increased synthesis of myofilaments and enlargement of existing cells, not an increase in cell number. ---

Question 12

A 35-year-old woman undergoes a thyroidectomy for Graves disease. Histologic examination of the thyroid gland shows follicular epithelial cells that are tall and columnar instead of the normal cuboidal shape. This finding is best explained by which of the following processes?

Accepted Answer

Hyperplasia with hypertrophy — In Graves disease, excessive TSH receptor stimulation leads to both increased number (hyperplasia) and increased size (hypertrophy) of follicular cells, causing them to become tall and columnar. This is a physiologic adaptation to hormonal stimulation, not a neoplastic or metaplastic change.

CELLULAR INJURY AND ADAPTATION MCQs

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