Nokea
Which of the following statements is NOT true
- A. T cells expressing CD4 exert their function mainly through secretion of cytokines
- B. CD8 T cells interact with MHC class I molecules on antigen presenting cells
- C. CD4 T cells can help B cells because B cells express MHC class II molecules and can present antigen to T cells
- D. CD3 is not necessary for TCR signaling in cytotoxic T cells
Correct Answer: D
Rationale: The correct answer is D because CD3 is indeed necessary for TCR signaling in cytotoxic T cells. CD3 is a crucial component of the T cell receptor (TCR) complex, which is responsible for initiating intracellular signaling upon recognition of antigen-MHC complexes. Without CD3, TCR signaling cannot occur, leading to impaired T cell activation and cytotoxic function. Choices A, B, and C are incorrect because they accurately describe the functions and interactions of T cells expressing CD4 and CD8 with antigen presenting cells, as well as the role of CD4 T cells in helping B cells through antigen presentation.
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Flu neuraminidase is
- A. A protein that allows the virus to escape the host immune response
- B. A surface protein that allows the release of newly formed viral particles
- C. The target of Tamiflu
- D. Both B and C are correct
Correct Answer: D
Rationale: The correct answer is D because flu neuraminidase is a surface protein that allows the release of newly formed viral particles and it is also the target of Tamiflu. Neuraminidase helps the virus spread by cleaving sialic acid from host cells, facilitating the release of viral particles. Tamiflu inhibits neuraminidase, preventing the spread of the virus. Option A is incorrect because neuraminidase does not directly help the virus escape the host immune response. Option B is partially correct but incomplete without mentioning Tamiflu. Option C is also partially correct but incomplete without mentioning the role of neuraminidase in releasing viral particles.
The nurse has contributed to a staff education program on immunity. Which participant response indicates a correct understanding of the type of immunity that protects newborns for the first 3 months of life as a result of maternal transmission of IgG?
- A. Active natural immunity occurs.
- B. Passive natural immunity occurs.
- C. Active artificial immunity occurs.
- D. Passive artificial immunity occurs.
Correct Answer: B
Rationale: The correct answer is B: Passive natural immunity occurs. This type of immunity is achieved through the transfer of antibodies (IgG) from the mother to the fetus during pregnancy. The antibodies provide protection to the newborn for the first few months of life. It is considered passive because the newborn is not actively producing the antibodies themselves.
A: Active natural immunity occurs when the body produces its antibodies in response to exposure to an antigen. This is not the case for newborns receiving maternal IgG.
C: Active artificial immunity occurs when the body is intentionally exposed to an antigen, such as through vaccination, to stimulate an immune response. This is not relevant to the scenario described.
D: Passive artificial immunity occurs when pre-formed antibodies are transferred to an individual through a medical intervention, such as receiving immune globulin. This is not applicable to the situation of maternal transmission of IgG to newborns.
Which of the statements below is NOT true. Integration is a stage of HIV life cycle that
- A. Utilizes a host enzyme called integrase
- B. Is a target of some anti-HIV drugs
- C. Allows duplication of proviral DNA when the infected cell divides
- D. Requires the formation of double stranded DNA
Correct Answer: A
Rationale: The correct answer is A. Integration is a stage of HIV life cycle that involves the insertion of viral DNA into the host cell's genome, facilitated by the enzyme integrase. To explain why A is incorrect, integrase is a viral enzyme, not a host enzyme.
B is correct as some anti-HIV drugs target the integration stage to prevent viral replication.
C is correct as integrated proviral DNA allows for duplication during cell division.
D is correct as integration requires the formation of double-stranded viral DNA.
One principal function of complement is to
- A. inactivate performs
- B. mediate the release of histamine
- C. Bind antibodies attached to cell surfaces and to lyse these cells
- D. phagocytize antigens
Correct Answer: C
Rationale: The correct answer is C because complement proteins bind antibodies attached to cell surfaces and cause cell lysis, enhancing immune response. Choice A is incorrect as complement does not inactivate performs. Choice B is incorrect as complement does not mediate the release of histamine. Choice D is incorrect as phagocytosis is a function of phagocytes, not complement proteins. Therefore, the correct function of complement is to enhance immune response by binding antibodies and causing cell lysis.
A male client is suspected of an immune system disorder. Which of the following important factors will the nurse document while assessing the client?
- A. The client’s diet
- B. The client’s drug history
- C. The client’s ability to produce antibodies
- D. The client’s family members’ history of chronic diseases
Correct Answer: B
Rationale: The client’s drug history is crucial as certain medications can affect immune function or mimic immune disorders.