What is the function of IgA?
- A. Allergy mediation
- B. Placental transfer
- C. Mucosal immunity
- D. Primary response
Correct Answer: C
Rationale: The correct answer is C: Mucosal immunity. IgA plays a crucial role in protecting mucosal surfaces, such as the lining of the gut and respiratory tract, from pathogens. It helps prevent infections by neutralizing and blocking the entry of harmful substances. IgA is not involved in allergy mediation (choice A), placental transfer (choice B), or primary response (choice D), as those functions are typically associated with other types of antibodies. IgA's specificity for mucosal surfaces makes it uniquely suited for providing defense at these vulnerable sites.
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The daughter of a man with Huntington’s disease is having presymptomatic genetic testing done. What does a positive result mean for her?
- A. She will get the disease.
- B. She is a carrier of Huntington’s disease.
- C. She will be at increased risk for developing the disease.
- D. She should change her diet, exercise, and environment to prevent the disease.
Correct Answer: A
Rationale: Huntington’s disease is dominantly inherited, meaning a positive test indicates she will develop the disease later in life.
What is the primary advantage of the memory function in adaptive immunity?
- A. Rapid and stronger responses to previously encountered antigens
- B. Direct killing of pathogens without prior activation
- C. Enhanced cytokine secretion
- D. Resistance to all infections without exposure
Correct Answer: A
Rationale: The correct answer is A because memory function in adaptive immunity allows for rapid and stronger responses to previously encountered antigens. This is achieved through the presence of memory cells, such as memory B and T cells, which can quickly recognize and respond to specific pathogens upon re-exposure. This leads to a faster and more efficient immune response, providing better protection against future infections.
Choice B is incorrect because direct killing of pathogens without prior activation is a function of innate immunity, not adaptive immunity. Choice C is incorrect as enhanced cytokine secretion is not the primary advantage of memory function. Choice D is incorrect because while memory function provides protection against previously encountered antigens, it does not confer resistance to all infections without exposure.
A patient is experiencing an immune response that involves the T lymphocytes. For which types of immunity should the nurse plan care for this patient?
- A. Passive immunity
- B. Humoral immunity
- C. Acquired immunity
- D. Cell-mediated immunity
Correct Answer: D
Rationale: The correct answer is D: Cell-mediated immunity. T lymphocytes are primarily involved in cell-mediated immunity, where they directly attack infected cells or pathogens. This type of immunity is crucial in fighting intracellular pathogens like viruses. Other choices are incorrect because:
A: Passive immunity involves receiving pre-formed antibodies, not T lymphocytes.
B: Humoral immunity involves B cells producing antibodies, not T lymphocytes.
C: Acquired immunity is a general term encompassing both humoral and cell-mediated immunity, but T lymphocytes specifically play a key role in cell-mediated immunity.
An 18-year-old college student with an exacerbation of systemic lupus erythematosus (SLE) has been receiving prednisone (Deltacone) 20 mg daily for 4 days. Which of these medical orders should you question?
- A. Discontinue prednisone after today’s dose.
- B. Administer first dose of varicella vaccine.
- C. Check patient’s C-reactive protein (CRP).
- D. Give ibuprofen (Advil) 800 mg every 6 hours.
Correct Answer: B
Rationale: The varicella vaccine is a live vaccine and should not be given to patients who are immunosuppressed such as those receiving prednisone. The other orders are appropriate for managing SLE and its symptoms.
A patient with acquired immunodeficiency syndrome (AIDS) has a negative tuberculosis (TB) skin test. Which nursing action is indicated next?
- A. Obtain a chest x-ray and sputum smear.
- B. No further action is needed after the negative skin test.
- C. Teach about the anti-tuberculosis drug isoniazid (INH).
- D. Schedule TB testing again in 6 months.
Correct Answer: A
Rationale: A negative TB skin test in an immunocompromised patient such as one with AIDS does not rule out TB infection. Further diagnostic testing such as a chest x-ray and sputum smear is necessary to confirm the absence of TB. Teaching about INH or scheduling another test is premature without further diagnostic confirmation.