Nokea
Select the wrong statement concerning TLR4
- A. TLR4 is expressed on dendritic cells and macrophages
- B. It represents an example of a phagocytic receptor
- C. It is expressed on the membrane in complex with a protein called MD2
- D. Mice resistant to endotoxic shock harbor a mutation of TLR4
Correct Answer: B
Rationale: The correct answer is B because TLR4 is not a phagocytic receptor, but rather a pattern recognition receptor involved in recognizing pathogen-associated molecular patterns (PAMPs).
A: Correct, TLR4 is expressed on dendritic cells and macrophages.
C: Correct, TLR4 is expressed on the membrane in complex with MD2.
D: Correct, mice resistant to endotoxic shock have a mutation in TLR4, indicating its role in the immune response to endotoxins.
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What happens to B cells after clonal selection and expansion?
- A. They produce cytokines
- B. They differentiate into plasma cells to produce antibodies
- C. They initiate phagocytosis
- D. They present antigens to T cells
Correct Answer: B
Rationale: After clonal selection and expansion, B cells differentiate into plasma cells to produce antibodies. This is crucial for the immune response as plasma cells are specialized in antibody production. B cells do not produce cytokines (choice A), initiate phagocytosis (choice C), or present antigens to T cells (choice D) post-clonal selection. Plasma cell differentiation is the key outcome of the B cell activation process, enabling the body to mount an effective immune response against pathogens.
Priority Decision: What is the most important nursing intervention for the prevention and treatment of pressure ulcers?
- A. Using pressure-reduction devices
- B. Massaging pressure areas with lotion
- C. Repositioning the patient a minimum of every 2 hours
- D. Using lift sheets and trapeze bars to facilitate patient movement
Correct Answer: C
Rationale: Regular repositioning prevents prolonged pressure on vulnerable areas, reducing the risk of tissue ischemia and necrosis.
naïve T cells can be found in
- A. Blood
- B. Germinal centers
- C. Mostly in the medullary region of lymph nodes (LN)
- D. In non-lymphoid tissues such as the skin
Correct Answer: A
Rationale: The correct answer is A: Blood. Naïve T cells are circulating in the blood, ready to encounter antigens. They can move to secondary lymphoid organs like lymph nodes. Germinal centers (B) are sites of B cell maturation, not where naïve T cells are primarily found. While some naïve T cells enter lymph nodes (C), they are not mostly located in the medullary region. Naïve T cells can also migrate to non-lymphoid tissues (D), but their primary residence is in the blood.
During exacerbations of SL, patients are often treated with:
- A. Antiemetics.
- B. Antineoplastics.
- C. Corticosteroids.
- D. Antibiotics.
Correct Answer: C
Rationale: Corticosteroids are commonly used during exacerbations of systemic lupus erythematosus (SLE) to reduce inflammation and suppress the immune system. Antineoplastics and antibiotics target different conditions and are not the primary treatment for SLE.
Which of the following complement components mediate inflammation?
- A. C3b
- B. C3a, C4a, and C5a
- C. C5b
- D. C1q
Correct Answer: B
Rationale: The correct answer is B (C3a, C4a, and C5a) because these complement components are known as anaphylatoxins that mediate inflammation by inducing vasodilation, increasing vascular permeability, and recruiting immune cells. C3b (choice A) is involved in opsonization, not inflammation. C5b (choice C) is part of the membrane attack complex for cell lysis. C1q (choice D) initiates the classical complement pathway, but it does not directly mediate inflammation.