Cellular Injury and Adaptation Practice Questions

64 multiple-choice questions on Cellular injury and adaptation for paramedic and EMT students, from Chapter 9 (Pathophysiology). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

64 practice questions

1. Pathophysiology is the study of:

   1. A. How drugs act on body tissues
   2. B. Normal function of healthy organs
   3. C. Normal structure of the organs
   4. D. How disease disrupts function
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   Answer: D. How disease disrupts function

   It connects what is wrong inside the cell to what you see at the bedside.

2. The most common cause of cellular injury is:

   1. A. Bacterial and viral infection
   2. B. Hypoxia from poor perfusion
   3. C. Toxic chemical exposure
   4. D. Inherited genetic defects
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   Answer: B. Hypoxia from poor perfusion

   Hypoxia, usually from inadequate perfusion, is the most common cause. Oxygen delivery failure underlies most emergencies you treat.

3. Ischemia refers to:

   1. A. Swelling of cells after injury
   2. B. Death of tissue from lack of oxygen
   3. C. Low oxygen content in arterial blood
   4. D. Inadequate blood flow to a tissue
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   Answer: D. Inadequate blood flow to a tissue

   Ischemia is inadequate blood flow; tissue death is infarction and low blood oxygen is hypoxemia. Prolonged ischemia leads to infarction.

4. The first cellular change in hypoxic injury is:

   1. A. Increased protein synthesis
   2. B. Rupture of the nuclear membrane
   3. C. Release of lysosomal enzymes
   4. D. A shift to anaerobic metabolism
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   Answer: D. A shift to anaerobic metabolism

   The cell shifts to anaerobic metabolism, which produces far less ATP. Falling ATP causes the sodium-potassium pump to fail.

5. When the sodium-potassium pump fails, the cell:

   1. A. Swells as sodium and water enter
   2. B. Loses sodium and gains potassium
   3. C. Increases its ATP production
   4. D. Shrinks as water moves out
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   Answer: A. Swells as sodium and water enter

   Cellular swelling is an early, reversible change.

6. Free radicals damage cells by:

   1. A. Triggering antibody attack on the cell
   2. B. Stealing electrons from cell structures
   3. C. Blocking oxygen binding to hemoglobin
   4. D. Blocking glucose entry into the cell
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   Answer: B. Stealing electrons from cell structures

   They steal electrons from membranes and other structures, setting off chain reactions. Reperfusion injury involves a burst of free radical production.

7. Apoptosis is:

   1. A. Swelling and rupture of the cell
   2. B. Uncontrolled cell death with inflammation
   3. C. Cell death caused by ischemia
   4. D. Programmed, orderly cell death
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   Answer: D. Programmed, orderly cell death

   Necrosis, by contrast, is disorderly and triggers inflammation.

8. Necrosis differs from apoptosis because necrosis:

   1. A. Leaves no cellular debris behind
   2. B. Is a genetically programmed process
   3. C. Causes cell rupture and inflammation
   4. D. Requires energy from ATP to proceed
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   Answer: C. Causes cell rupture and inflammation

   The inflammation is what produces much of the tissue damage.

9. Atrophy refers to:

   1. A. An increase in cell size
   2. B. A change in cell type
   3. C. An increase in cell number
   4. D. A decrease in cell size
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   Answer: D. A decrease in cell size

   Atrophy is a decrease in cell size and organ mass from disuse or reduced stimulation. An immobilized limb loses muscle mass this way.

10. Hypertrophy refers to:

    1. A. Decreased cell number
    2. B. Change in mature cell type
    3. C. Increased cell number
    4. D. Increased cell size
    Show answer

    Answer: D. Increased cell size

    The left ventricle hypertrophies in long-standing hypertension.

11. Hyperplasia refers to:

    1. A. Abnormal changes in cell shape
    2. B. An increase in the size of cells
    3. C. A change from one cell type to another
    4. D. An increase in the number of cells
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    Answer: D. An increase in the number of cells

    It occurs in tissues capable of dividing.

12. Metaplasia is:

    1. A. One mature cell type replaced by another
    2. B. An increase in the number of cells
    3. C. Disordered growth in cell size and shape
    4. D. Loss of differentiation in malignant cells
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    Answer: A. One mature cell type replaced by another

    Airway cells in a smoker convert to a more durable but less functional type.

13. Dysplasia refers to:

    1. A. A normal adaptive increase in cell size
    2. B. Programmed death of damaged cells
    3. C. Abnormal cell size, shape, and order
    4. D. Replacement of one cell type by another
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    Answer: C. Abnormal cell size, shape, and order

    Dysplasia is abnormal change in cell size, shape, and organization. It may precede cancer and is often detected by screening.

14. Chemical injury to cells may come from:

    1. A. Industrial chemicals but not medications
    2. B. Illegal drugs and poisons only
    3. C. Toxins that are swallowed, not inhaled
    4. D. Medications, alcohol, and toxins
    Show answer

    Answer: D. Medications, alcohol, and toxins

    Sources include medications, alcohol, recreational drugs, carbon monoxide, and environmental toxins. Carbon monoxide blocks oxygen transport and use.

15. Cells can be injured by:

    1. A. External agents but not immune reactions
    2. B. Hypoxia alone, as all injury ends in it
    3. C. Many agents, including hypoxia and chemicals
    4. D. Infection and trauma, but not chemicals
    Show answer

    Answer: C. Many agents, including hypoxia and chemicals

    Causes include hypoxia, chemicals, infection, immune reactions, physical agents, nutritional imbalance, and genetic defects. Hypoxia is the most common.

16. The first visible change in a hypoxic cell is:

    1. A. Shrinkage as water leaves the cell
    2. B. Swelling as sodium and water enter
    3. C. Rupture of the outer cell membrane
    4. D. Fragmentation of the nucleus
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    Answer: B. Swelling as sodium and water enter

    Reversible if oxygen is restored.

17. Reversible cellular injury differs from irreversible injury because:

    1. A. The cell recovers if oxygen is restored
    2. B. It does not affect cell membrane pumps
    3. C. It produces no structural changes in the cell
    4. D. It always resolves without any treatment
    Show answer

    Answer: A. The cell recovers if oxygen is restored

    Restoring oxygen and nutrients allows recovery. Time is the deciding factor.

18. Irreversible injury is marked by:

    1. A. Cellular swelling with intact membranes
    2. B. Mild dysfunction that resolves with oxygen
    3. C. A shift to anaerobic metabolism alone
    4. D. Membrane rupture and nuclear breakdown
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    Answer: D. Membrane rupture and nuclear breakdown

    Membrane rupture, mitochondrial damage, and nuclear breakdown mark the point of no return.

19. Hypoxic injury progresses to death faster in:

    1. A. Brain and heart cells
    2. B. Skeletal muscle cells
    3. C. Bone and cartilage cells
    4. D. Skin and fat cells
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    Answer: A. Brain and heart cells

    Brain and heart cells have high metabolic demand. Brain cells die within minutes.

20. Ischemia differs from hypoxia because ischemia:

    1. A. Is always reversible when flow returns
    2. B. Also cuts off nutrients and waste removal
    3. C. Involves only low arterial oxygen content
    4. D. Is a milder form of oxygen deprivation
    Show answer

    Answer: B. Also cuts off nutrients and waste removal

    Reduced blood flow also impairs nutrient delivery and waste removal, so ischemia is worse than hypoxia alone.

21. Infarction refers to:

    1. A. Inflammation following tissue injury
    2. B. Reversible injury from brief ischemia
    3. C. Tissue death from prolonged ischemia
    4. D. Swelling of tissue from fluid leak
    Show answer

    Answer: C. Tissue death from prolonged ischemia

    Myocardial infarction is the classic example.

22. Free radicals are generated during:

    1. A. Sleep and other low-metabolism states
    2. B. Only exposure to ionizing radiation
    3. C. Digestion of fats and proteins only
    4. D. Reperfusion, radiation, and inflammation
    Show answer

    Answer: D. Reperfusion, radiation, and inflammation

    Reperfusion, radiation, inflammation, and certain chemicals generate them. Normal oxygen metabolism produces them too.

23. Antioxidants protect cells by:

    1. A. Speeding repair of damaged DNA
    2. B. Neutralizing free radicals
    3. C. Slowing the cell's metabolic rate
    4. D. Increasing cellular oxygen supply
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    Answer: B. Neutralizing free radicals

    Vitamins C and E are examples.

24. A patient who took 30 g of acetaminophen 2 days ago is now jaundiced and confused. The mechanism of cell injury is:

    1. A. A toxic metabolite destroying liver cells
    2. B. Shock-induced ischemia of the liver
    3. C. An immune attack on drug-coated liver cells
    4. D. Bile duct blockage backing bile into the liver
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    Answer: A. A toxic metabolite destroying liver cells

    Acetaminophen is harmless until the liver converts it to a toxic metabolite (NAPQI). In overdose, glutathione is depleted and the metabolite destroys liver cells, causing jaundice and encephalopathy days later. The injury is direct chemical toxicity, not low blood flow, an immune reaction, or a blocked bile duct.

25. Carbon tetrachloride and acetaminophen injure which organ primarily?

    1. A. Heart
    2. B. Lung
    3. C. Liver
    4. D. Kidney
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    Answer: C. Liver

    The liver metabolizes them into toxic products.

26. Lead poisoning affects primarily:

    1. A. The skin, hair, and nails
    2. B. The liver, gallbladder, and pancreas
    3. C. Nerves, blood, and kidneys
    4. D. The lungs, airways, and pleura
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    Answer: C. Nerves, blood, and kidneys

    Lead affects the nervous system, blood, and kidneys. Children are especially vulnerable.

27. Carbon monoxide injures cells by:

    1. A. Causing swelling of the upper airway
    2. B. Displacing oxygen as an inert gas
    3. C. Binding hemoglobin and cytochromes
    4. D. Triggering widespread inflammation
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    Answer: C. Binding hemoglobin and cytochromes

    It binds hemoglobin, blocking oxygen transport, and binds mitochondrial cytochromes, blocking cellular oxygen use. CO is not an inert simple asphyxiant; it binds chemically at very low concentrations.

28. Ethanol injures cells through:

    1. A. Dehydration from its diuretic effect alone
    2. B. Triggering an immune attack on the liver
    3. C. Toxicity, metabolites, and malnutrition
    4. D. Blocking hemoglobin from carrying oxygen
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    Answer: C. Toxicity, metabolites, and malnutrition

    Direct toxicity, toxic metabolic byproducts, and nutritional deficiency all contribute. Liver, brain, and heart are affected.

29. Infectious agents injure cells by:

    1. A. Releasing toxins but never invading
    2. B. Inflammation alone, never direct damage
    3. C. Direct destruction of cells only
    4. D. Invasion, toxins, and immune responses
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    Answer: D. Invasion, toxins, and immune responses

    They invade directly, release toxins, and trigger harmful immune responses. Sometimes the immune response does more damage than the organism.

30. Exotoxins are:

    1. A. Toxic products of viral replication
    2. B. Components of the bacterial cell wall
    3. C. Proteins secreted by living bacteria
    4. D. Released only when bacteria die
    Show answer

    Answer: C. Proteins secreted by living bacteria

    Tetanus and botulinum toxins are examples.

31. Endotoxins are:

    1. A. Toxins produced by fungal spores
    2. B. Proteins secreted by living bacteria
    3. C. Toxic products of viral replication
    4. D. Gram-negative cell wall components
    Show answer

    Answer: D. Gram-negative cell wall components

    They are released when gram-negative bacteria die and trigger sepsis and shock.

32. Physical agents that injure cells include:

    1. A. Heat, cold, radiation, and electricity
    2. B. Drugs, alcohol, poisons, and toxins
    3. C. Bacteria, viruses, fungi, and parasites
    4. D. Antibodies, complement, and histamine
    Show answer

    Answer: A. Heat, cold, radiation, and electricity

    Physical agents include heat, cold, radiation, electricity, and mechanical force. Each has a distinct mechanism.

33. Heat injures cells by:

    1. A. Slowing cellular enzyme activity
    2. B. Denaturing cellular proteins
    3. C. Forming ice crystals in cells
    4. D. Damaging DNA with ionizing energy
    Show answer

    Answer: B. Denaturing cellular proteins

    Heat denatures proteins and disrupts membranes. Protein denaturation begins above about 41 degrees C.

34. Cold injures cells by:

    1. A. Damaging DNA through ionization
    2. B. Raising the cellular metabolic rate
    3. C. Denaturing proteins and enzymes
    4. D. Ice crystals and vasoconstriction
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    Answer: D. Ice crystals and vasoconstriction

    Ice crystal formation, vasoconstriction, and microvascular clotting all contribute. Frostbite is the classic example. DNA damage from ionizing energy is how radiation injures cells.

35. Radiation injures cells by:

    1. A. Heating tissue until proteins denature
    2. B. Damaging DNA and generating free radicals
    3. C. Blocking oxygen binding to hemoglobin
    4. D. Directly rupturing the cell membrane
    Show answer

    Answer: B. Damaging DNA and generating free radicals

    Rapidly dividing cells are most sensitive.

36. Electrical injury damages cells through:

    1. A. Nerve effects without tissue heating
    2. B. Heat and effects on excitable tissue
    3. C. Cardiac effects without tissue heating
    4. D. Surface burns at contact points only
    Show answer

    Answer: B. Heat and effects on excitable tissue

    Current generates heat, directly affects excitable tissue such as heart and nerve, and disrupts tissue along its path. External burns underestimate internal damage.

37. Nutritional injury occurs with:

    1. A. Vitamin deficiencies but not excess
    2. B. Both deficiency and excess of nutrients
    3. C. Excess intake but not deficiency
    4. D. Starvation and protein deficiency only
    Show answer

    Answer: B. Both deficiency and excess of nutrients

    Obesity and malnutrition both injure.

38. Genetic causes of cellular injury include:

    1. A. Chromosome number abnormalities only
    2. B. Inherited disease but not acquired change
    3. C. Acquired mutations from toxins only
    4. D. Inherited and acquired mutations
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    Answer: D. Inherited and acquired mutations

    Mutations may be inherited or acquired from environmental damage. Cancer involves acquired mutations.

39. Cellular adaptation is:

    1. A. A permanent change that cannot be undone
    2. B. A change that is always beneficial to the body
    3. C. A reversible change that helps the cell survive
    4. D. A change that is always harmful to the cell
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    Answer: C. A reversible change that helps the cell survive

    It can become maladaptive.

40. Atrophy of a muscle after a cast is removed is:

    1. A. Reversible with use
    2. B. A form of necrosis
    3. C. Pathologic and progressive
    4. D. Permanent loss of muscle
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    Answer: A. Reversible with use

    Disuse atrophy recovers with activity.

41. Physiologic hypertrophy occurs in:

    1. A. A trained athlete's heart
    2. B. A heart with aortic stenosis
    3. C. A failing heart after infarction
    4. D. A heart in chronic hypertension
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    Answer: A. A trained athlete's heart

    Examples include an athlete's heart or a weight lifter's muscles. Pathologic hypertrophy results from disease.

42. Pathologic hypertrophy of the heart occurs in:

    1. A. Hypertension and valve disease
    2. B. Uncomplicated normal pregnancy
    3. C. Normal aging without disease
    4. D. Endurance training in athletes
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    Answer: A. Hypertension and valve disease

    Chronic hypertension and valve disease cause it. It eventually fails.

43. An endurance athlete's heart muscle cells enlarge, while the uterine lining in pregnancy grows by adding cells. These are, respectively:

    1. A. Hyperplasia and hypertrophy
    2. B. Metaplasia and dysplasia
    3. C. Atrophy and hyperplasia
    4. D. Hypertrophy and hyperplasia
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    Answer: D. Hypertrophy and hyperplasia

    Hypertrophy is an increase in cell size; cardiac muscle cells mostly cannot divide, so they enlarge. Hyperplasia is an increase in cell number, as in the hormonally stimulated endometrium. Metaplasia and dysplasia are changes in cell type and organization. Atrophy is shrinkage.

44. Compensatory hyperplasia occurs when:

    1. A. Cells shrink from lack of stimulation
    2. B. Hormones stimulate tissue growth
    3. C. Tissue regrows after partial removal
    4. D. A tissue is chronically overstimulated
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    Answer: C. Tissue regrows after partial removal

    The remaining tissue regenerates, as the liver does after partial removal.

45. Hormonal hyperplasia occurs in:

    1. A. The uterus during pregnancy
    2. B. Skeletal muscle with training
    3. C. Nerve tissue after injury
    4. D. The heart during exercise
    Show answer

    Answer: A. The uterus during pregnancy

    Examples include the uterus in pregnancy and the breast during lactation, driven by estrogen and other hormones.

46. Metaplasia in a smoker's airway involves:

    1. A. Enlargement of mucus-secreting cells
    2. B. Death of ciliated airway cells
    3. C. Multiplication of normal ciliated cells
    4. D. Columnar cells replaced by squamous cells
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    Answer: D. Columnar cells replaced by squamous cells

    Ciliated columnar cells are replaced with squamous cells. Protective but loses function.

47. Metaplasia is significant because it:

    1. A. Causes necrosis of the tissue
    2. B. Is already an early form of cancer
    3. C. Is permanent once it has developed
    4. D. Can lead to dysplasia and cancer
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    Answer: D. Can lead to dysplasia and cancer

    Metaplasia is the replacement of one mature cell type by another, such as squamous cells replacing columnar cells in a smoker's bronchi. It is an adaptation, not necrosis and not yet cancer, and it is reversible: removing the stimulus can reverse it, but if the stimulus continues it may progress to dysplasia and then cancer.

48. Dysplasia is considered:

    1. A. A precancerous change
    2. B. An always benign change
    3. C. A normal adaptive change
    4. D. An established cancer
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    Answer: A. A precancerous change

    It may regress or progress.

49. Anaplasia refers to:

    1. A. Enlargement of cells under workload
    2. B. Loss of cell differentiation
    3. C. Increase in number of normal cells
    4. D. Normal maturation of immature cells
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    Answer: B. Loss of cell differentiation

    Anaplasia is the loss of differentiation seen in malignant tumors. Anaplastic cells look primitive.

50. Neoplasia refers to:

    1. A. Normal growth of tissue in childhood
    2. B. Reversible adaptation to stress
    3. C. Programmed death of damaged cells
    4. D. Uncontrolled new cell growth
    Show answer

    Answer: D. Uncontrolled new cell growth

    Neoplasia is new, uncontrolled growth forming a tumor, which may be benign or malignant.

51. Dead tissue in a deep burn triggers intense local inflammation, while worn-out skin cells die quietly without any. The burn tissue death is:

    1. A. Apoptosis
    2. B. Atrophy
    3. C. Metaplasia
    4. D. Necrosis
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    Answer: D. Necrosis

    Necrosis is unplanned cell death in which cells swell and rupture, releasing contents that cause inflammation. Apoptosis is programmed, orderly death without inflammation. Atrophy is cell shrinkage, and metaplasia is replacement of one cell type by another.

52. Coagulative necrosis typically occurs in:

    1. A. Brain infarction from stroke
    2. B. Bacterial abscess cavities
    3. C. Fatty tissue of the pancreas
    4. D. Heart and kidney infarcts
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    Answer: D. Heart and kidney infarcts

    It occurs in infarction of solid organs. Tissue architecture is preserved briefly.

53. Liquefactive necrosis typically occurs in:

    1. A. Brain infarction and abscesses
    2. B. Pulmonary tuberculosis lesions
    3. C. Pancreatitis and breast trauma
    4. D. Myocardial and renal infarcts
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    Answer: A. Brain infarction and abscesses

    Tissue becomes liquid.

54. Caseous necrosis is characteristic of:

    1. A. Heart attack
    2. B. Stroke
    3. C. Tuberculosis
    4. D. Pancreatitis
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    Answer: C. Tuberculosis

    Cheese-like appearance.

55. Fat necrosis occurs in:

    1. A. Myocardial infarction and angina
    2. B. Tuberculosis and fungal infection
    3. C. Pancreatitis and breast trauma
    4. D. Ischemic stroke and brain abscess
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    Answer: C. Pancreatitis and breast trauma

    Enzymes digest fat.

56. Gangrene refers to:

    1. A. Reversible ischemic tissue injury
    2. B. Infection without any tissue death
    3. C. Inflammation limited to the skin
    4. D. Necrosis of a large area of tissue
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    Answer: D. Necrosis of a large area of tissue

    It is often accompanied by infection. Dry, wet, and gas gangrene.

57. Gas gangrene is caused by:

    1. A. Fungal infection of tissue
    2. B. Clostridium bacteria
    3. C. Viral infection of muscle
    4. D. Poor circulation alone
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    Answer: B. Clostridium bacteria

    Clostridium species produce gas in tissue. Rapidly progressive and lethal.

58. Apoptosis is important because it:

    1. A. Quietly removes damaged cells
    2. B. Causes the damage seen in infarction
    3. C. Triggers inflammation to clear debris
    4. D. Occurs only in diseased tissue
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    Answer: A. Quietly removes damaged cells

    It removes damaged or unneeded cells without inflammation. Failure of apoptosis contributes to cancer.

59. Cellular aging involves:

    1. A. Wear and tear alone, without genetics
    2. B. Accumulated damage and shortened telomeres
    3. C. Genetic programming alone, without damage
    4. D. Lengthened telomeres and better repair
    Show answer

    Answer: B. Accumulated damage and shortened telomeres

    Reduced repair capacity also contributes. Aging is both programmed and damage-related.

60. Senescence refers to:

    1. A. Programmed death of aging cells
    2. B. Cells dividing without control
    3. C. Adaptive shrinkage of cells with age
    4. D. Cells losing the ability to divide
    Show answer

    Answer: D. Cells losing the ability to divide

    Part of aging.

61. Pathophysiology helps the paramedic by:

    1. A. Providing definitive field diagnoses
    2. B. Determining exact medication doses
    3. C. Replacing the need for protocols
    4. D. Explaining why findings occur
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    Answer: D. Explaining why findings occur

    It explains what is happening inside the patient so findings make sense, connecting signs to mechanisms.

62. Which cell type is most vulnerable to hypoxia?

    1. A. Neuron
    2. B. Fibroblast
    3. C. Bone cell
    4. D. Skin cell
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    Answer: A. Neuron

    Minutes without oxygen cause permanent damage.

63. Which tissue tolerates hypoxia longest?

    1. A. Cerebral cortex and retina
    2. B. Kidney tubules and liver
    3. C. Heart muscle and kidney
    4. D. Skin and skeletal muscle
    Show answer

    Answer: D. Skin and skeletal muscle

    Hours rather than minutes.

64. Cellular swelling is clinically significant because:

    1. A. It causes pain by stretching tissues
    2. B. It causes fever by releasing pyrogens
    3. C. It lowers blood volume by trapping water
    4. D. It raises intracranial pressure
    Show answer

    Answer: D. It raises intracranial pressure

    Swelling of brain cells raises intracranial pressure: cerebral edema.