Practice 9 MCQs on CELLULAR INJURY AND ADAPTATION MCQs with OmpathStudy. Built for Kenyan medical and health students to revise key concepts and prepare for...
Q1. 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?
Answer: Hypertrophy ANSWER: E
Explanation: 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.
Q2. 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?
Answer: Acute pancreatitis ANSWER: E
Explanation: The focal, chalky white deposits are areas of fat necrosis resulting from the release of pancreatic lipases in a patient with acute pancreatitis.
Q3. In an experiment, cells are subjected to radiant energy in the form of x-rays. This results in cell injury caused by hydrolysis of water. Which of the following cellular enzymes protects the cells from this type of injury?
Answer: Glutathione peroxidase
Explanation: Intracellular mechanisms exist that deal with free radical generation, as can occur with radiant injury from irradiation. Glutathione peroxidase reduces such injury by catalyzing the breakdown of hydrogen peroxide.
Q4. 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?
Answer: Liquefactive necrosis
Explanation: 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."
Q5. 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?
Answer: Germ cells
Explanation: 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.
Q6. 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?
Answer: Apoptosis
Explanation: 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.
Q7. 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?
Answer: Lobular hyperplasia
Explanation: 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.
Q8. 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?
Answer: Myometrial smooth muscle hypertrophy
Explanation: 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.
Q9. 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?
Answer: Endoplasmic reticulum
Explanation: 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