Nokea
Which hypersensitivity type is mediated by T cells?
- A. Type I
- B. Type II
- C. Type III
- D. Type IV
Correct Answer: D
Rationale: The correct answer is D: Type IV hypersensitivity. This type is mediated by T cells, specifically CD4+ helper T cells and CD8+ cytotoxic T cells. The process involves antigen-presenting cells activating T cells, leading to a delayed response. Choices A, B, and C involve different mechanisms and are not mediated by T cells. Type I is mediated by IgE antibodies, Type II involves antibody-mediated cell destruction, and Type III involves immune complex deposition. Therefore, Type IV is the only hypersensitivity type directly mediated by T cells.
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Choose the correct sequence in an allergic reaction.
- A. Allergen → mast cells → histamine → B cells → IgE antibodies
- B. Allergen → IgE antibodies → B cells → histamine → mast cells
- C. Allergen → B cells → IgE antibodies → mast cells → histamine
- D. Allergen → histamine → mast cells → IgE antibodies → B cells
Correct Answer: C
Rationale: Rationale for Answer C:
1. Allergen exposure triggers B cells to produce IgE antibodies specific to the allergen.
2. IgE antibodies bind to mast cells sensitizing them.
3. Upon re-exposure to allergen, allergen binds to IgE on mast cells.
4. This triggers release of histamine and other chemicals causing allergic symptoms.
Summary:
- Choice A: Incorrect because B cells do not produce IgE antibodies before allergen exposure.
- Choice B: Incorrect because IgE antibodies are produced by B cells, not the other way around.
- Choice D: Incorrect because histamine is released after allergen binds to IgE on sensitized mast cells.
A 21-year-old patient says no one in his family has type 1 diabetes mellitus but he has had it since childhood. He asks how his diabetes was transmitted to him. The nurse should explain to him that this disease is
- A. a single gene disorder
- B. a chromosome disorder
- C. an acquired genetic disorder
- D. a multifactorial genetic disorder
Correct Answer: D
Rationale: Type 1 diabetes is considered a multifactorial genetic disorder influenced by multiple genes and environmental factors rather than being caused by a single gene or chromosome.
A client has been newly diagnosed with systemic lupus erythematosus and is reviewing self-care measures with the nurse. Which statement by the client indicates a need to review the material?
- A. I will avoid direct sunlight as much as possible.
- B. Baby powder is good for the constant sweating.
- C. Grouping errands will help prevent fatigue.
- D. Rest time will have to become a priority.
Correct Answer: B
Rationale: The correct answer is B. Baby powder is not recommended for individuals with systemic lupus erythematosus, as it can irritate the skin and worsen symptoms. A: Avoiding direct sunlight is crucial due to photosensitivity. C: Grouping errands helps conserve energy. D: Rest is important to manage fatigue. Summary: A, C, and D are all appropriate self-care measures for a client with systemic lupus erythematosus, while using baby powder is not recommended.
All of the following are true with respect to IgE molecules, EXCEPT which one?
- A. They are the principal immunoglobulin class involved in allergic reactions.
- B. They are involved in mediating anti-parasitic immune responses.
- C. They will cross the placenta and fix complement.
- D. They can effect the release of histamine and other chemical mediators.
Correct Answer: C
Rationale: The correct answer is C. IgE molecules do not cross the placenta and fix complement, unlike IgG. IgE is the principal immunoglobulin in allergic reactions (A), mediates anti-parasitic immune responses (B), and triggers the release of histamine and other mediators (D). IgE plays a specific role in allergic responses and defense against parasites. IgG is the main immunoglobulin that crosses the placenta and fixes complement. Therefore, IgE does not share this function.
Peripheral nervous system (PNS)
- A. Located outside the CNS
- B. Consists of Nerves and Ganglia
- C. Brain & Spinal cord
- D. A& b
Correct Answer: D
Rationale: Step-by-step rationale:
1. The Peripheral Nervous System (PNS) includes nerves and ganglia, making choice B correct.
2. PNS is located outside the Central Nervous System (CNS), supporting choice A.
3. Since both A and B are accurate statements, the correct answer is D.
Summary:
- Choice A is correct because the PNS is located outside the CNS.
- Choice B is correct as the PNS includes nerves and ganglia.
- Choice C is incorrect as it refers to the CNS (Brain & Spinal cord).