Immunity and Inflammation Practice Questions

71 multiple-choice questions on Immunity and inflammation 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.

71 practice questions

1. Innate immunity includes:

   1. A. Memory cells from prior exposure
   2. B. Barriers, inflammation, and phagocytes
   3. C. Protection created by vaccination
   4. D. Antibody production by B cells
   Show answer

   Answer: B. Barriers, inflammation, and phagocytes

   It responds to any invader. It is fast and nonspecific.

2. Adaptive immunity is characterized by:

   1. A. Specific antigen recognition and memory
   2. B. An immediate, nonspecific response to any invader
   3. C. The complement cascade acting on its own
   4. D. Physical barriers such as the skin and mucosa
   Show answer

   Answer: A. Specific antigen recognition and memory

   It is why a second exposure produces a faster response.

3. Humoral immunity is mediated by:

   1. A. B lymphocytes
   2. B. Mast cells
   3. C. Neutrophils
   4. D. T lymphocytes
   Show answer

   Answer: A. B lymphocytes

   B cells produce antibodies, which circulate in plasma and body fluids.

4. Cell-mediated immunity is mediated by:

   1. A. Complement proteins
   2. B. T lymphocytes
   3. C. B lymphocytes
   4. D. Circulating antibodies
   Show answer

   Answer: B. T lymphocytes

   T cells attack infected or abnormal cells directly. They handle viruses, cancer cells, and transplanted tissue.

5. An antigen is:

   1. A. A white cell that engulfs microbes
   2. B. An antibody made by B cells
   3. C. A clotting factor in plasma
   4. D. A substance recognized as foreign
   Show answer

   Answer: D. A substance recognized as foreign

   Vaccines introduce antigens to build memory safely.

6. The cardinal signs of acute inflammation are:

   1. A. Redness, heat, swelling, and pain
   2. B. Redness, heat, itching, and blistering
   3. C. Fever, chills, and sweating
   4. D. Weakness, fatigue, and malaise
   Show answer

   Answer: A. Redness, heat, swelling, and pain

   Loss of function is the fifth sign. They result from vasodilation and increased permeability. Itching and blistering can accompany some reactions but are not cardinal signs; swelling and pain are.

7. Histamine released from mast cells causes:

   1. A. Increased clotting and thrombosis
   2. B. Vasoconstriction and pallor
   3. C. Reduced mucus secretions
   4. D. Vasodilation and capillary leak
   Show answer

   Answer: D. Vasodilation and capillary leak

   It also causes bronchoconstriction. This is the core of an allergic reaction.

8. Fever aids the immune response by:

   1. A. Making conditions hostile to pathogens
   2. B. Directly killing all bacteria
   3. C. Slowing cellular metabolism
   4. D. Improving oxygen delivery to tissues
   Show answer

   Answer: A. Making conditions hostile to pathogens

   It also enhances immune activity. Very high fevers still carry their own risks.

9. A type I hypersensitivity reaction is:

   1. A. Delayed by several days
   2. B. Caused by immune complexes
   3. C. Immediate and IgE-mediated
   4. D. Mediated by T cells
   Show answer

   Answer: C. Immediate and IgE-mediated

   Anaphylaxis is the example. Symptoms typically appear within minutes to an hour.

10. A delayed hypersensitivity reaction such as contact dermatitis is:

    1. A. Type III, immune complex
    2. B. Type II, antibody-mediated
    3. C. Type I, IgE-mediated
    4. D. Type IV, cell-mediated
    Show answer

    Answer: D. Type IV, cell-mediated

    Poison ivy is the classic example.

11. Autoimmune disease occurs when:

    1. A. A vaccine fails to produce immunity
    2. B. Antibody production stops entirely
    3. C. The immune system attacks the body
    4. D. The immune system is deficient
    Show answer

    Answer: C. The immune system attacks the body

    Lupus and rheumatoid arthritis are examples.

12. Immunodeficiency may result from:

    1. A. Asthma treated with an albuterol inhaler
    2. B. Seasonal allergic rhinitis
    3. C. Recent routine vaccination
    4. D. HIV, chemotherapy, or steroids
    Show answer

    Answer: D. HIV, chemotherapy, or steroids

    Some chronic diseases also cause it. These patients may present without typical signs of infection. Albuterol is a bronchodilator and does not suppress immunity.

13. An immunocompromised patient with a serious infection may:

    1. A. Mount an unusually high fever
    2. B. Form pus more readily at the site
    3. C. Show a larger white count rise
    4. D. Have a blunted response
    Show answer

    Answer: D. Have a blunted response

    Fever may be minimal with few localizing signs. Maintain a high index of suspicion. Weak immune systems produce less fever, less pus, and smaller white count changes, so infections can look mild.

14. Anaphylaxis differs from a mild allergic reaction because it:

    1. A. Involves only hives and itching
    2. B. Always resolves without treatment
    3. C. Involves multiple body systems
    4. D. Develops over several days
    Show answer

    Answer: C. Involves multiple body systems

    Airway compromise or hypotension is common. Epinephrine is the first-line treatment.

15. Vaccines work by:

    1. A. Suppressing inflammation
    2. B. Killing circulating bacteria
    3. C. Providing ready-made antibodies
    4. D. Building memory without disease
    Show answer

    Answer: D. Building memory without disease

    They expose the immune system to an antigen. Passive immunity, such as immunoglobulin, provides antibodies directly.

16. Chronic inflammation differs from acute inflammation by:

    1. A. Resolving within a few days
    2. B. Involving mainly neutrophils
    3. C. Persisting and damaging tissue
    4. D. Starting with sudden redness and heat
    Show answer

    Answer: C. Persisting and damaging tissue

    It persists for weeks or longer, often causing scarring. It contributes to atherosclerosis and many chronic diseases. Neutrophils and abrupt redness and heat are hallmarks of acute inflammation; chronic inflammation is dominated by macrophages and lymphocytes.

17. The first line of defense against infection is:

    1. A. Circulating antibodies
    2. B. Cytotoxic T lymphocytes
    3. C. Skin and mucous membranes
    4. D. Fever and inflammation
    Show answer

    Answer: C. Skin and mucous membranes

    Chemical barriers such as stomach acid also count. Intact skin is remarkably effective.

18. The second line of defense is:

    1. A. Memory B and T cells
    2. B. Antibodies from plasma cells
    3. C. Inflammation and phagocytosis
    4. D. Vaccine-induced immunity
    Show answer

    Answer: C. Inflammation and phagocytosis

    Complement is also part of it. Nonspecific but fast.

19. The third line of defense is:

    1. A. Skin and mucous membranes
    2. B. Phagocytosis by neutrophils
    3. C. Adaptive B and T cell immunity
    4. D. Inflammation and fever
    Show answer

    Answer: C. Adaptive B and T cell immunity

    Specific and remembers.

20. Neutrophils are:

    1. A. Antibody-producing cells
    2. B. First cells to engulf bacteria
    3. C. Long-lived memory cells
    4. D. Cells that drive allergic reactions
    Show answer

    Answer: B. First cells to engulf bacteria

    They arrive first at infection. Pus is largely dead neutrophils.

21. Macrophages function to:

    1. A. Release histamine in allergy
    2. B. Engulf pathogens and present antigens
    3. C. Form platelet plugs in bleeding
    4. D. Produce antibodies against toxins
    Show answer

    Answer: B. Engulf pathogens and present antigens

    They also clear debris. They bridge innate and adaptive immunity.

22. Natural killer cells:

    1. A. Produce antibodies to viruses
    2. B. Kill infected and tumor cells
    3. C. Release histamine in allergy
    4. D. Need prior sensitization to act
    Show answer

    Answer: B. Kill infected and tumor cells

    They act without prior sensitization. Part of innate immunity.

23. Mast cells release:

    1. A. Complement proteins
    2. B. Interferon gamma
    3. C. IgE antibodies
    4. D. Histamine
    Show answer

    Answer: D. Histamine

    They release histamine and other mediators during allergic reactions. Found in tissues near vessels.

24. Complement proteins:

    1. A. Enhance inflammation and lyse cells
    2. B. Form clots at sites of injury
    3. C. Produce antibodies against bacteria
    4. D. Reset the hypothalamic set point
    Show answer

    Answer: A. Enhance inflammation and lyse cells

    They also mark pathogens. A cascade like clotting.

25. Interferons are:

    1. A. Mediators released by mast cells
    2. B. Antibodies made by plasma cells
    3. C. Complement proteins that lyse invading cells
    4. D. Proteins that block viral replication
    Show answer

    Answer: D. Proteins that block viral replication

    Antiviral signaling.

26. Cytokines are:

    1. A. Foreign antigens
    2. B. Antibody proteins
    3. C. White blood cells
    4. D. Signaling molecules
    Show answer

    Answer: D. Signaling molecules

    They coordinate immune responses. Interleukins and tumor necrosis factor are examples.

27. A cytokine storm is:

    1. A. A mild, self-limited allergic skin reaction
    2. B. A loss of immune cell production
    3. C. Normal localized inflammation
    4. D. Uncontrolled, damaging cytokine release
    Show answer

    Answer: D. Uncontrolled, damaging cytokine release

    Seen in severe infections and some therapies.

28. Antibodies are produced by:

    1. A. Plasma cells
    2. B. Natural killer cells
    3. C. Helper T cells
    4. D. Tissue macrophages
    Show answer

    Answer: A. Plasma cells

    Plasma cells derive from B lymphocytes. Each plasma cell makes one antibody type.

29. IgG antibodies:

    1. A. Mainly protect mucosa
    2. B. Appear first in infection
    3. C. Trigger allergies
    4. D. Cross the placenta
    Show answer

    Answer: D. Cross the placenta

    IgG is the most abundant and provides long-term immunity. Passive immunity for newborns.

30. IgM antibodies:

    1. A. Cross the placenta to the fetus
    2. B. Appear first in infection
    3. C. Trigger allergic reactions
    4. D. Protect mucous membranes
    Show answer

    Answer: B. Appear first in infection

    Indicate recent infection.

31. IgA antibodies:

    1. A. Trigger allergic reactions
    2. B. Are found in saliva and milk
    3. C. Cross the placenta to the fetus
    4. D. Appear first in infection
    Show answer

    Answer: B. Are found in saliva and milk

    Also in tears. Mucosal defense.

32. IgE antibodies:

    1. A. Activate mast cells to trigger allergy
    2. B. Cross the placenta to protect the fetus
    3. C. Provide lasting immunity after vaccination
    4. D. Appear first in a new infection
    Show answer

    Answer: A. Activate mast cells to trigger allergy

    IgE binds mast cells and basophils; re-exposure triggers histamine release, making it the key mediator of anaphylaxis. IgG crosses the placenta; IgM appears first.

33. Helper T cells:

    1. A. Directly kill virus-infected cells
    2. B. Release histamine during allergy
    3. C. Activate B cells and other T cells
    4. D. Secrete antibodies into the plasma
    Show answer

    Answer: C. Activate B cells and other T cells

    Helper (CD4) T cells coordinate the immune response by activating B cells and other T cells. HIV targets them.

34. Cytotoxic T cells:

    1. A. Kill infected or abnormal cells
    2. B. Release histamine from their granules
    3. C. Secrete antibodies against bacteria
    4. D. Activate B cells to make antibodies
    Show answer

    Answer: A. Kill infected or abnormal cells

    Important against viruses and cancer.

35. Regulatory T cells:

    1. A. Suppress immune responses
    2. B. Kill tumor cells on direct contact
    3. C. Produce antibodies after B-cell help
    4. D. Amplify responses to new antigens
    Show answer

    Answer: A. Suppress immune responses

    Regulatory T cells act as immune brakes, suppressing immune responses to prevent autoimmunity.

36. Memory cells:

    1. A. Die off once the infection clears
    2. B. Allow rapid response on re-exposure
    3. C. Release histamine on second exposure
    4. D. Belong to the innate immune system
    Show answer

    Answer: B. Allow rapid response on re-exposure

    Memory B and T cells persist after exposure and allow a rapid response on re-exposure. They are the basis of vaccination.

37. Primary immune response:

    1. A. Is rapid because antibodies are ready
    2. B. Is stronger than later responses
    3. C. Is slower, on first antigen exposure
    4. D. Relies on existing memory cells
    Show answer

    Answer: C. Is slower, on first antigen exposure

    The primary response occurs on first exposure to an antigen and takes days to build.

38. Secondary immune response:

    1. A. Is faster and stronger due to memory
    2. B. Is weaker because of tolerance
    3. C. Is slower because antibodies are used up
    4. D. Occurs only after vaccination
    Show answer

    Answer: A. Is faster and stronger due to memory

    Memory cells make the secondary response faster and stronger, which is why second infections are often milder.

39. Active immunity results from:

    1. A. Receiving antibodies from a donor
    2. B. Antibodies passed in breast milk
    3. C. Making one's own antibodies
    4. D. An injection of immune globulin
    Show answer

    Answer: C. Making one's own antibodies

    Active immunity comes from exposure to antigen through infection or vaccination, producing one's own antibodies. It is long-lasting.

40. Passive immunity results from:

    1. A. A live attenuated vaccine series
    2. B. Repeated low-level antigen exposure
    3. C. Receiving preformed antibodies
    4. D. Recovering from a natural infection
    Show answer

    Answer: C. Receiving preformed antibodies

    Passive immunity comes from preformed antibodies, such as maternal antibodies or immune globulin. It is temporary.

41. Inflammation's purpose is to:

    1. A. Raise body temperature to kill germs
    2. B. Destroy tissue around the injury
    3. C. Produce antibodies at the wound site
    4. D. Contain injury and begin repair
    Show answer

    Answer: D. Contain injury and begin repair

    Inflammation contains injury, removes debris, and begins repair. It is protective but can overshoot.

42. The vascular phase of inflammation involves:

    1. A. Clot formation that seals capillaries
    2. B. Lymphatic closure that traps fluid
    3. C. Vasodilation and increased permeability
    4. D. Sustained vasoconstriction to stop flow
    Show answer

    Answer: C. Vasodilation and increased permeability

    A brief vasoconstriction is followed by vasodilation and increased permeability, producing redness and swelling.

43. The cellular phase of inflammation involves:

    1. A. White cell migration to the injury
    2. B. Collagen deposition and scarring
    3. C. Platelet plug and clot formation
    4. D. Vasodilation and leaky capillaries
    Show answer

    Answer: A. White cell migration to the injury

    Neutrophils arrive first.

44. Chemotaxis refers to:

    1. A. White cell migration to signals
    2. B. Programmed death of injured cells
    3. C. Engulfing of debris by macrophages
    4. D. Vessel dilation caused by histamine
    Show answer

    Answer: A. White cell migration to signals

    Chemotaxis is movement of white cells toward chemical signals released at the injury, following the trail. Engulfing debris is phagocytosis.

45. Exudate is:

    1. A. Protein- and cell-rich leaked fluid
    2. B. Clear fluid from heart failure edema
    3. C. Protein-poor fluid from high pressure
    4. D. Lymph returning to the circulation
    Show answer

    Answer: A. Protein- and cell-rich leaked fluid

    Exudate is fluid rich in protein and cells that leaks from vessels during inflammation; pus is a type of exudate. Protein-poor pressure-driven fluid is transudate.

46. Fever is produced by:

    1. A. Bacteria directly heating the tissues
    2. B. Pyrogens resetting the hypothalamus
    3. C. Muscle activity outpacing heat loss
    4. D. Peripheral vasodilation trapping heat
    Show answer

    Answer: B. Pyrogens resetting the hypothalamus

    Cytokines such as IL-1 are endogenous pyrogens. Pyrogens raise the hypothalamic temperature set point.

47. A parent asks whether to treat her alert, well-hydrated child's fever of 38.6 C (101.5 F). Which statement is most accurate?

    1. A. A fever above 38 C will cause brain damage
    2. B. Fever should always be fully eliminated quickly
    3. C. Fever means the child needs antibiotics today
    4. D. Fever helps fight infection; treat for comfort
    Show answer

    Answer: D. Fever helps fight infection; treat for comfort

    Fever is a normal defense: pyrogens reset the hypothalamus, and higher temperatures impair pathogens and boost immune function. Antipyretics are for comfort. Ordinary fevers do not cause brain damage, and lowering the temperature does not prevent febrile seizures. Many fevers are viral and need no antibiotics.

48. Febrile seizures occur in:

    1. A. Adults with high bacterial fevers
    2. B. Newborns in the first month of life
    3. C. Young children with fever
    4. D. Older adults with severe sepsis
    Show answer

    Answer: C. Young children with fever

    Febrile seizures typically affect young children (about 6 months to 5 years) with a rapidly rising temperature. Usually benign but frightening.

49. Chronic inflammation involves:

    1. A. Eosinophils and IgE antibody release
    2. B. Mast cells and acute histamine release
    3. C. Mainly neutrophils and edema
    4. D. Macrophages, lymphocytes, and fibrosis
    Show answer

    Answer: D. Macrophages, lymphocytes, and fibrosis

    Atherosclerosis and arthritis.

50. Granuloma formation occurs in:

    1. A. Healing of clean surgical wounds
    2. B. Immediate allergic reactions
    3. C. Acute bacterial infections like strep
    4. D. Chronic infections like TB
    Show answer

    Answer: D. Chronic infections like TB

    Granulomas form in chronic inflammation when the agent cannot be eliminated, as in tuberculosis; macrophages wall off the problem.

51. Wound healing by first intention occurs with:

    1. A. Large open wounds left to granulate
    2. B. Clean wounds with edges together
    3. C. Full-thickness burn injuries
    4. D. Infected wounds packed open
    Show answer

    Answer: B. Clean wounds with edges together

    Clean, closed wounds with edges approximated heal by first intention with minimal scarring.

52. Wound healing by second intention occurs with:

    1. A. Open wounds filling with granulation
    2. B. Sutured surgical incisions
    3. C. Wounds closed after a few days' delay
    4. D. Clean lacerations closed with glue
    Show answer

    Answer: A. Open wounds filling with granulation

    Open wounds fill with granulation tissue from the base up, producing more scarring. Delayed closure is third intention.

53. Factors impairing wound healing include:

    1. A. Diabetes, poor perfusion, steroids
    2. B. Young age and good circulation
    3. C. Moist dressings and wound cleaning
    4. D. High-protein diet and adequate rest
    Show answer

    Answer: A. Diabetes, poor perfusion, steroids

    Poor perfusion, diabetes, infection, steroids, and malnutrition all impair healing; diabetic foot ulcers are the classic example.

54. Type II hypersensitivity involves:

    1. A. Immune complexes in vessel walls
    2. B. IgE binding to mast cells
    3. C. Sensitized T cells after 48 hours
    4. D. Antibodies against cell surfaces
    Show answer

    Answer: D. Antibodies against cell surfaces

    Type II (cytotoxic) reactions involve antibodies attacking cell surfaces, as in transfusion reactions.

55. Type III hypersensitivity involves:

    1. A. Antibodies against red cell surfaces
    2. B. Delayed T cell-mediated reactions
    3. C. Immune complex deposits, as in lupus
    4. D. IgE-mediated mast cell release
    Show answer

    Answer: C. Immune complex deposits, as in lupus

    Immune complex deposition causes inflammation, as in lupus and serum sickness.

56. A patient develops an itchy, blistering rash 48 hours after contact with poison ivy. This reaction is:

    1. A. Type I, IgE-mediated
    2. B. Type IV, T cell-mediated
    3. C. Type II, antibodies against cells
    4. D. Type III, immune complexes
    Show answer

    Answer: B. Type IV, T cell-mediated

    Contact dermatitis is a delayed (type IV) reaction driven by sensitized T cells, and it peaks 1 to 3 days after exposure. Type I is the immediate IgE/mast cell response, as in anaphylaxis. Type II involves antibodies against cell surfaces, as in a transfusion reaction. Type III involves immune complex deposits, as in lupus.

57. Allergens are:

    1. A. Normally harmless triggers of sensitization
    2. B. Toxins that directly injure cells on contact
    3. C. Pathogens that invade and damage host tissue
    4. D. Bacteria that colonize the mucous membranes
    Show answer

    Answer: A. Normally harmless triggers of sensitization

    Allergens are normally harmless substances (pollen, foods, drugs, venom) that trigger immune responses in sensitized people.

58. Sensitization means:

    1. A. Silent IgE priming on first exposure
    2. B. Lasting protective immunity to the antigen
    3. C. Tolerance after repeated exposure
    4. D. An immediate reaction on first contact
    Show answer

    Answer: A. Silent IgE priming on first exposure

    On first exposure, IgE is produced without symptoms, priming mast cells for later reactions; the second exposure causes the reaction.

59. Urticaria refers to:

    1. A. A flat red rash from heat
    2. B. Deep swelling of the lips and face
    3. C. Hives: raised, itchy welts
    4. D. Fluid-filled blisters on the skin
    Show answer

    Answer: C. Hives: raised, itchy welts

    Urticaria (hives) results from histamine release in the skin. Deep swelling is angioedema.

60. Angioedema involves:

    1. A. Deep swelling of face, lips, and airway
    2. B. Generalized itching without any swelling
    3. C. Raised welts on the skin surface
    4. D. Flushing and redness of the trunk
    Show answer

    Answer: A. Deep swelling of face, lips, and airway

    Angioedema is deeper tissue swelling, often of the face, lips, and airway, with risk of airway compromise.

61. Fifteen minutes after eating shrimp, a patient with a shellfish allergy has hives and repeated vomiting but no wheezing and a normal BP. Which statement is correct?

    1. A. This is a mild reaction, since there is no wheezing
    2. B. This is anaphylaxis: two systems after a likely allergen
    3. C. It is not anaphylaxis, since that requires hypotension
    4. D. Antihistamines alone are adequate for this reaction
    Show answer

    Answer: B. This is anaphylaxis: two systems after a likely allergen

    Anaphylaxis is a rapid, multisystem reaction. Skin involvement plus GI symptoms after a likely allergen meets the criteria, and IM epinephrine is indicated. Hypotension and wheezing are not required, and waiting for them delays treatment. Antihistamines are adjuncts only.

62. Biphasic anaphylaxis means:

    1. A. Skin signs followed by GI signs
    2. B. A mild reaction then tolerance
    3. C. Reaction to two allergens at once
    4. D. Symptoms return hours later
    Show answer

    Answer: D. Symptoms return hours later

    Symptoms recur hours after initial resolution, so observation is important. It can occur up to 72 hours later without re-exposure.

63. Autoimmune diseases include:

    1. A. Leukemia, lymphoma, and myeloma
    2. B. Strep throat, Lyme disease, and TB
    3. C. Lupus, RA, type 1 diabetes, and MS
    4. D. Hay fever, asthma, and eczema
    Show answer

    Answer: C. Lupus, RA, type 1 diabetes, and MS

    Lupus, rheumatoid arthritis, type 1 diabetes, and multiple sclerosis result when self-tolerance fails.

64. Immunosuppression increases risk of:

    1. A. Autoimmune attack on organs
    2. B. Exaggerated inflammatory swelling and pain
    3. C. Severe allergic reactions
    4. D. Infections, including unusual organisms
    Show answer

    Answer: D. Infections, including unusual organisms

    Immunosuppression raises the risk of infection, including opportunistic organisms, and some cancers.

65. Which patient is most likely to have a blunted fever and few signs despite a serious infection?

    1. A. A healthy 30-year-old runner with a fever
    2. B. A teenager with a cold and a sore throat
    3. C. A patient with seasonal allergies and a cough
    4. D. A transplant patient on immunosuppressants
    Show answer

    Answer: D. A transplant patient on immunosuppressants

    Immunosuppressants, chemotherapy, steroids, and HIV blunt the inflammatory response. These patients may have little fever or localized signs even with sepsis, so a subtle change needs a high index of suspicion. The other patients have normal immune function.

66. Transplant rejection involves:

    1. A. An allergic reaction to the drugs
    2. B. Infection carried in the donor organ
    3. C. Donor cells attacking the recipient
    4. D. Immune attack on the graft
    Show answer

    Answer: D. Immune attack on the graft

    The recipient's immune system attacks the transplanted tissue; immunosuppressants prevent it. Donor cells attacking the recipient is graft-versus-host disease.

67. Graft-versus-host disease occurs when:

    1. A. Donor immune cells attack the recipient
    2. B. Recipient immune cells attack the graft
    3. C. The graft becomes infected after surgery
    4. D. The recipient develops a drug allergy
    Show answer

    Answer: A. Donor immune cells attack the recipient

    After bone marrow transplant.

68. A nurse vaccinated against hepatitis B years ago gets a needlestick. Why may she be protected?

    1. A. Vaccine memory cells mount a rapid secondary response
    2. B. Vaccine antibodies stay at peak levels in the blood forever
    3. C. The vaccine kills the virus on contact at the wound site
    4. D. The vaccine gave her passive immunity that lasts for life
    Show answer

    Answer: A. Vaccine memory cells mount a rapid secondary response

    A vaccine exposes the immune system to antigen so that memory B and T cells form. On later exposure they produce a faster, stronger secondary response, even after antibody levels have fallen. Vaccination produces active immunity, not passive. The exposure still needs reporting and follow-up per protocol.

69. Immunosenescence refers to:

    1. A. Inherited immune deficiency in children
    2. B. Age-related decline in immunity
    3. C. Allergy that develops late in life
    4. D. Autoimmunity triggered by aging
    Show answer

    Answer: B. Age-related decline in immunity

    Older adults respond less to vaccines and infection. Inherited immune deficiencies of childhood are primary immunodeficiencies, not age-related decline.

70. Stress affects immunity by:

    1. A. Boosting antibody production over time
    2. B. Triggering allergic sensitization
    3. C. Suppressing it through cortisol
    4. D. Stimulating T cells via cortisol
    Show answer

    Answer: C. Suppressing it through cortisol

    Chronic stress raises infection risk. Chronic stress weakens antibody responses, and cortisol inhibits T-cell activity rather than stimulating it.

71. Nutrition affects immunity because:

    1. A. Immune cells need no dietary input
    2. B. Immune cells need protein and micronutrients
    3. C. Only vitamin C intake affects immune function
    4. D. Only total calories affect immunity
    Show answer

    Answer: B. Immune cells need protein and micronutrients

    Protein, vitamins, and minerals are required for immune cell function; malnutrition causes immunodeficiency.