Nokea
Which of the following is NOT an example of a pathogen-associated molecular pattern (PAMP)?
- A. Lipopolysaccharide (LPS)
- B. Peptidoglycan
- C. Viral RNA
- D. MHC molecules
Correct Answer: D
Rationale: The correct answer is D, MHC molecules. PAMPs are conserved molecules found on pathogens that can trigger an immune response. MHC molecules are not PAMPs; they are part of the host's immune system used to present antigens to T cells. LPS, peptidoglycan, and viral RNA are examples of PAMPs as they are specific molecules found on pathogens that can be recognized by pattern recognition receptors on immune cells to initiate an immune response.
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What is the structural composition of an antibody?
- A. Two heavy chains and two light chains
- B. Three heavy chains and one light chain
- C. Two heavy chains and three light chains
- D. Four heavy chains
Correct Answer: A
Rationale: The correct answer is A: Two heavy chains and two light chains. Antibodies are composed of two identical heavy chains and two identical light chains. Heavy chains provide structural support and effector functions, while light chains contribute to antigen binding. Choice B is incorrect as antibodies do not have three heavy chains. Choice C is incorrect as antibodies do not have three light chains. Choice D is incorrect as antibodies do not have four heavy chains.
Individuals unable to make the J protein found in certain immunoglobulins would be expected to have frequent infections of the
- A. intestinal tract
- B. blood.
- C. liver.
- D. pancreas.
Correct Answer: A
Rationale: The correct answer is A: intestinal tract. The J protein is crucial for the proper functioning of immunoglobulins in the mucosal immune system, which plays a major role in defending against pathogens in the intestinal tract. Without the J protein, individuals would have impaired immune responses in the gut, leading to frequent infections in the intestinal tract. Choices B, C, and D are incorrect because the J protein deficiency specifically affects the mucosal immune system in the intestinal tract, not the blood, liver, or pancreas.
In LN naïve T cells and activated dendritic cells interact in the
- A. Subcapsular sinus
- B. Cortex
- C. Paracortex
- D. Medulla
Correct Answer: C
Rationale: The correct answer is C: Paracortex. Naïve T cells circulate through the blood and lymphatic system until they encounter antigens presented by activated dendritic cells in the paracortex of lymph nodes. The paracortex is the region where T cell activation and proliferation occur, leading to an immune response. The subcapsular sinus (A) is primarily involved in filtering lymph fluid, the cortex (B) contains B cell follicles, and the medulla (D) contains plasma cells and macrophages. Thus, the paracortex is the specific site of interaction between naïve T cells and activated dendritic cells in lymph nodes.
What cytokine is produced by Regulatory T cells to suppress immune responses?
- A. IL-2
- B. IL-10
- C. IFN-gamma
- D. TNF-alpha
Correct Answer: B
Rationale: The correct answer is B: IL-10. Regulatory T cells produce IL-10 to suppress immune responses by inhibiting the activation and function of other immune cells. IL-2 (A) is mainly produced by activated T cells to promote proliferation. IFN-gamma (C) is produced by T cells and NK cells to enhance immune response. TNF-alpha (D) is produced by macrophages and T cells to induce inflammation. IL-10 stands out as the suppressor cytokine in this context.
The nurse is counseling a group of individuals over the age of 50 with average risk for cancer about screening tests for cancer. Which screening recommendation should be performed to screen for colorectal cancer?
- A. Barium enema every year
- B. Colonoscopy every 10 years
- C. Fecal occult blood every 5 years
- D. Annual prostate-specific antigen (PSA) and digital rectal exam
Correct Answer: B
Rationale: Colonoscopy every 10 years is recommended for colorectal cancer screening in individuals over 50 with average risk.