Nokea
What is the primary function of cytokines in the immune system?
- A. To act as a physical barrier to pathogens
- B. To orchestrate and drive immune responses
- C. To destroy red blood cells
- D. To generate antibodies
Correct Answer: B
Rationale: The correct answer is B: To orchestrate and drive immune responses. Cytokines are signaling molecules that coordinate various aspects of the immune response, such as inflammation, cell proliferation, and differentiation. They regulate communication between immune cells to mount an effective defense against pathogens.
A: To act as a physical barrier to pathogens - Incorrect. Physical barriers include skin and mucous membranes, not cytokines.
C: To destroy red blood cells - Incorrect. Cytokines are not involved in destroying red blood cells.
D: To generate antibodies - Incorrect. While cytokines can influence antibody production, their primary role is not in generating antibodies.
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The National Marrow Donor Program obtains hematopoietic stem cells from donors for recipients in need. When discussing this donation with the donor, what should the nurse know about these stem cells?
- A. They must come from an embryo or umbilical cord.
- B. These cells will form new blood cells for the recipient.
- C. Taking these cells will cause the donor to become anemic.
- D. These cells must be removed with a bone marrow aspiration.
Correct Answer: B
Rationale: Hematopoietic stem cells donated through programs like the National Marrow Donor Program help generate new blood cells for recipients, aiding in treating various blood disorders.
Concerning multiple sclerosis (MS), which of the following is NOT correct
- A. Some HLA alleles confer susceptibility to MS
- B. A gender bias is observed with females more at risk for MS than males
- C. Exhibits a North-South gradient, with a higher incidence reported for populations living above the equator
- D. Affects mostly individuals over 65 yrs. of age
Correct Answer: D
Rationale: The correct answer is D because multiple sclerosis (MS) typically affects individuals between 20-50 years old, with the most common age of onset being between 20-40 years. MS is not primarily a disease of older individuals over 65 years. Choices A, B, and C are incorrect because various HLA alleles have been associated with MS susceptibility, females are indeed more at risk for MS than males, and there is a known North-South gradient in MS incidence, with higher rates reported for populations living farther from the equator.
The most abundant class of immunoglobulin in serum is
- A. IgE
- B. IgA
- C. IgD
- D. IgG
Correct Answer: D
Rationale: The correct answer is D: IgG. IgG is the most abundant class of immunoglobulin in serum, constituting about 75% of total immunoglobulins. IgG plays a crucial role in humoral immunity, providing long-term protection against pathogens. IgE (A) is involved in allergic responses, IgA (B) is mainly found in mucosal secretions, and IgD (C) functions as a cell surface receptor on B cells. IgG is the primary immunoglobulin responsible for secondary immune responses and provides the bulk of the adaptive immune response.
The nurse is performing an assessment on the patient who is in bilateral Buck traction. Which finding indicates the need to reposition the patient?
- A. The patient's heels are not touching the surface of the mattress.
- B. The elastic bandages need to be revrapped.
- C. The patient's feet are against the footboard.
- D. The weights are hanging free.
Correct Answer: C
Rationale: The correct answer is C because if the patient's feet are against the footboard in Buck traction, it can cause pressure ulcers and compromise circulation. Repositioning the patient is necessary to ensure proper alignment and prevent complications.
Incorrect choices:
A: The patient's heels not touching the mattress can be due to the traction pulling the legs in a specific position.
B: Rewrapping the elastic bandages may be necessary for proper traction maintenance but doesn't indicate immediate need for repositioning.
D: The weights hanging free is a normal finding in Buck traction and indicates proper traction application.
One principal function of the Class I and Class II major histocompatibility complex S proteins is to
- A. transduce the signal to the T-cell interior following antigen binding
- B. mediate immunoglobulin class switching
- C. present antigen for recognition by the T-cell antigen receptor
- D. stimulate production of interleukins
Correct Answer: C
Rationale: The correct answer is C because Class I and Class II MHC proteins present antigens to T-cell receptors for immune response activation. Class I MHC presents endogenous antigens to CD8+ T cells, while Class II MHC presents exogenous antigens to CD4+ T cells. Choice A is incorrect because MHC proteins do not transduce signals. Choice B is incorrect because MHC proteins do not mediate immunoglobulin class switching. Choice D is incorrect because MHC proteins do not directly stimulate interleukin production.