Which complement components are primarily involved in Type III hypersensitivity?
- A. C1 and C4
- B. C3a and C5a
- C. C5b and C6
- D. C2 and C7
Correct Answer: B
Rationale: The correct answer is B: C3a and C5a. In Type III hypersensitivity reactions, immune complexes form and deposit in tissues, leading to complement activation. C3a and C5a are anaphylatoxins released during complement activation, causing inflammation and tissue damage in Type III hypersensitivity.
Rationale:
A: C1 and C4 are primarily involved in Type I hypersensitivity reactions.
C: C5b and C6 are part of the membrane attack complex in the classical pathway of complement activation, not specific to Type III hypersensitivity.
D: C2 and C7 are involved in the classical pathway of complement activation but not directly implicated in Type III hypersensitivity reactions.
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You are evaluating an HIV-positive patient who is receiving IV pentamidine (Pentam) as a treatment for Pneumocystis carinii pneumonia. Which information is most important to communicate to the physician?
- A. The blood pressure decreased to 104/76 during administration.
- B. The patient is complaining of pain at the site of the infusion.
- C. The patient is not taking in an adequate amount of oral fluids.
- D. Blood glucose is 55 mg/dL after the medication administration.
Correct Answer: D
Rationale: Pentamidine can cause hypoglycemia which is a serious and potentially life-threatening side effect. A blood glucose level of 55 mg/dL is critically low and requires immediate intervention. The other findings while important are less urgent and can be managed with standard nursing interventions.
A cell type capable of killing virus-infected cells that provides early protection against viral infection is
- A. Eosinophils
- B. NK cells
- C. Neutrophils
- D. Mast cells
Correct Answer: B
Rationale: The correct answer is B: NK cells. NK cells are part of the innate immune system and can directly kill virus-infected cells, providing early protection against viral infections. They do not require prior exposure to the virus to initiate their killing mechanism, making them crucial for early defense. Eosinophils (A), Neutrophils (C), and Mast cells (D) are not primarily involved in killing virus-infected cells. Eosinophils are more associated with parasitic infections, Neutrophils are primarily involved in bacterial infections, and Mast cells are involved in allergic reactions.
The mucociliary escalator protects
- A. The gut
- B. The skin
- C. The respiratory tract
- D. All of the above sites
Correct Answer: C
Rationale: The mucociliary escalator is a defense mechanism in the respiratory tract that traps and removes inhaled particles and pathogens by using cilia to move mucus out of the lungs. This helps to prevent infections and maintain lung health. Choices A and B are incorrect because the mucociliary escalator specifically functions in the respiratory tract, not the gut or skin. Choice D is incorrect because the mucociliary escalator does not protect all of the mentioned sites, only the respiratory tract.
Amino acids are building blocks of
- A. Carbohydrates
- B. Nucleic acids
- C. Lipids
- D. Proteins
Correct Answer: D
Rationale: The correct answer is D: Proteins. Amino acids are the building blocks of proteins because they are linked together in a specific sequence to form protein chains. Proteins are essential for various biological functions in the body.
Incorrect options:
A: Carbohydrates - Carbohydrates are made up of sugar molecules, not amino acids.
B: Nucleic acids - Nucleic acids, like DNA and RNA, are made up of nucleotides, not amino acids.
C: Lipids - Lipids are composed of fatty acids and glycerol, not amino acids.
Molecules that are considered members of the 'immunoglobulin superfamily':
- A. Contain one or more protein domains with a compact barrel structure
- B. Are always lymphocyte antigen receptors
- C. Are highly unstable relative to other proteins
- D. All of the above
Correct Answer: A
Rationale: The correct answer is A because molecules in the immunoglobulin superfamily typically contain one or more protein domains with a compact barrel structure. This structure is characteristic of immunoglobulin-like domains found in proteins involved in immune responses. Choice B is incorrect because not all members of the immunoglobulin superfamily are lymphocyte antigen receptors. Choice C is incorrect as these molecules are not necessarily highly unstable compared to other proteins. Therefore, the correct answer is A as it accurately describes a common structural feature of molecules in the immunoglobulin superfamily.