Nokea
Which of the following complement components is an opsonin?
- A. C3a
- B. C3b
- C. C4a
- D. C5a
Correct Answer: B
Rationale: The correct answer is B: C3b. C3b is an opsonin because it coats pathogens, making them more recognizable by phagocytic cells for ingestion and destruction. C3a, C4a, and C5a are anaphylatoxins that mediate inflammatory responses by activating immune cells, not opsonins.
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Emphysema is characterized by ______.
- A. the loss of elasticity of the lungs
- B. spasms of the bronchioles due to exposure to allergens
- C. abnormal growth of epithelial cells that line the bronchioles
- D. excessive mucus production in the lower respiratory pathways
Correct Answer: A
Rationale: Rationale:
A: Emphysema is characterized by the destruction of alveolar walls and loss of elasticity of the lungs, leading to air trapping and difficulty exhaling. This results in reduced gas exchange and airflow limitation.
B: Bronchospasms are more commonly associated with conditions like asthma, not emphysema.
C: Abnormal growth of epithelial cells is seen in conditions like lung cancer, not emphysema.
D: Excessive mucus production is characteristic of conditions like chronic bronchitis, not emphysema.
Summary: The correct answer is A because emphysema specifically involves the loss of elasticity of the lungs due to destruction of alveoli, leading to impaired airflow. Choices B, C, and D are incorrect as they describe features more indicative of other respiratory conditions.
To provide free water and intracellular fluid hydration for a patient with acute gastroenteritis who is NPO, the nurse would expect administration of which infusion?
- A. Dextrose 5% in water
- B. Dextrose 10% in water
- C. Lactated Ringer’s solution
- D. Dextrose 5% in normal saline (0.9%)
Correct Answer: A
Rationale: D5W provides free water without adding significant electrolytes, aiding intracellular hydration.
All of the following are true of antigen EXCEPT which one of the following?
- A. They contain paratopes
- B. They will react with antibodies.
- C. They contain antigenic determinants.
- D. They can elicit an immune response.
Correct Answer: A
Rationale: The correct answer is A. Paratopes are actually parts of antibodies that bind to antigens, not the antigens themselves. A is incorrect because antigens do not contain paratopes; rather, they contain epitopes or antigenic determinants that are recognized by antibodies. B, C, and D are true statements about antigens. B is true because antigens react with antibodies. C is true because antigens contain antigenic determinants that antibodies recognize. D is true because antigens can elicit an immune response by stimulating the production of antibodies. Therefore, the correct answer is A because antigens do not contain paratopes.
TLRs contain a cytoplasmic TIR domain also found in the receptor of
- A. Type I Interferons
- B. IL-1β
- C. TNF-α
- D. IL-8
Correct Answer: B
Rationale: Step-by-step rationale for Choice B (IL-1β) being correct:
1. The TIR domain is present in Toll-like receptors (TLRs) and IL-1 receptor.
2. TLRs recognize various microbial products, while IL-1 receptor binds IL-1 cytokines.
3. Both TLRs and IL-1 receptor signal through the TIR domain.
4. IL-1β is a cytokine that binds to IL-1 receptor, which contains a TIR domain.
Summary of why the other choices are incorrect:
A: Type I Interferons - Type I interferons signal through JAK-STAT pathway, not TIR domain.
C: TNF-α - TNF receptor family signals through TNF receptor-associated death domain, not TIR domain.
D: IL-8 - IL-8 binds to CXCR1 and CXCR2 receptors, which do not contain a TIR domain.
In summary, Choice B
To prevent the debilitating cycle of fatigue-depression-fatigue in patients receiving radiation therapy, what should the nurse encourage the patient to do?
- A. Implement a walking program
- B. Ignore the fatigue as much as possible
- C. Do the most stressful activities when fatigue is tolerable
- D. Schedule rest periods throughout the day whether fatigue is present or not
Correct Answer: D
Rationale: Scheduled rest periods help break the cycle of fatigue and depression.