Nokea
Which cells are the most important phagocytes in innate immunity?
- A. Natural killer cells and B lymphocytes
- B. Macrophages and neutrophils
- C. T cells and dendritic cells
- D. Basophils and eosinophils
Correct Answer: B
Rationale: The correct answer is B - Macrophages and neutrophils are the most important phagocytes in innate immunity. Macrophages are versatile cells that engulf and destroy pathogens, while neutrophils are the most abundant phagocytes in the blood and are critical for early immune responses. Natural killer cells and B lymphocytes (A) are not phagocytes, but rather involved in adaptive immunity. T cells and dendritic cells (C) play roles in adaptive immunity and antigen presentation, not direct phagocytosis. Basophils and eosinophils (D) are involved in allergic reactions and parasitic infections, not primary phagocytic functions.
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Phagocytes were discovered by:
- A. Ilya Metchnikoff
- B. Louis Pasteur
- C. Emil von Behring
- D. Robert Koch
Correct Answer: A
Rationale: The correct answer is A: Ilya Metchnikoff. He discovered phagocytes through his research on immune responses in starfish larvae. Metchnikoff observed cells engulfing foreign particles, leading to the discovery of phagocytosis. Louis Pasteur is famous for his work in microbiology and vaccination. Emil von Behring discovered antitoxins. Robert Koch is known for his work in bacteriology and identifying the causative agents of diseases. Therefore, the correct answer is A as Metchnikoff specifically discovered phagocytes.
A patient identified as HIV antibody–positive 1 year ago manifests acute HIV infection but does not want to start antiretroviral therapy at this time. What is an appropriate nursing intervention for the patient at this stage of illness?
- A. Assist with end-of-life issues
- B. Provide care during acute exacerbations
- C. Provide physical care for chronic diseases
- D. Teach the patient about immune enhancement
Correct Answer: D
Rationale: Immune enhancement strategies, such as nutrition and stress reduction, can help maintain health until the patient decides to initiate ART.
Recognize the following that would be classified as a delayed hypersensitivity reaction.
- A. Anaphylaxis
- B. Allergic contact dermatitis
- C. Cytotoxic hypersensitivity
- D. Immune complex hypersensitivity
Correct Answer: B
Rationale: The correct answer is B: Allergic contact dermatitis. This is classified as a delayed hypersensitivity reaction because it involves activation of T cells, which takes time to develop. Anaphylaxis (A) is an immediate hypersensitivity reaction mediated by IgE. Cytotoxic hypersensitivity (C) involves antibodies attacking cells directly, not delayed. Immune complex hypersensitivity (D) involves immune complexes depositing in tissues, triggering inflammation, not T cell activation.
Which complement protein is the main component of the Membrane Attack Complex (MAC)?
- A. C1
- B. C3
- C. C5b
- D. C4b
Correct Answer: C
Rationale: The correct answer is C: C5b. The Membrane Attack Complex (MAC) is formed by a sequence of complement proteins, with C5b playing a crucial role as the initiator. After C5b binds to the target cell membrane, it triggers the assembly of C6, C7, C8, and multiple C9 molecules to form the MAC pore. C1 (A) is the initiator of the classical pathway, not a component of the MAC. C3 (B) is involved in the formation of the C3 convertase and opsonization but is not the main component of the MAC. C4b (D) is part of the classical pathway and is involved in the formation of the C3 convertase, not the MAC.
An immune response to polysaccharide subunit vaccines can be obtained
- A. If the vaccines is administered with adjuvants
- B. Only after multiple booster injections
- C. Only if administered orally
- D. If the polysaccharide subunit is coupled to a protein carrier
Correct Answer: D
Rationale: The correct answer is D because coupling the polysaccharide subunit to a protein carrier enhances the immune response by converting the T-independent response to a T-dependent response. This allows for the induction of memory B cells and long-lasting immunity. Adjuvants (choice A) may enhance immune response but are not essential for polysaccharide-protein conjugate vaccines. Multiple booster injections (choice B) are not required for polysaccharide-protein conjugate vaccines as a single dose can induce a robust immune response. Administering orally (choice C) is not the only route for obtaining an immune response to polysaccharide subunit vaccines.