All of the following are true with respect to IgM antibodies EXCEPT which one

Correct Answer: D

Rationale: The correct answer is D. IgM antibodies do not mediate allergic reactions. IgE antibodies are responsible for allergic reactions. IgM antibodies fix complement, occur on the surface of lymphocytes, and predominate in the primary response to antigens. IgM is the first antibody produced in response to an infection, playing a key role in the activation of the complement system. IgM antibodies are mainly found in the blood and lymphatic system, not on the surface of lymphocytes. IgE antibodies are the primary mediators of allergic reactions by triggering the release of histamine and other inflammatory molecules.

Correct Answer: D

Rationale: The correct answer is D: Minor loss of function. A grade 2 sprain involves partial tearing of the ligament, leading to moderate pain, swelling, and a significant loss of function. In contrast, a grade 3 sprain involves complete tearing of the ligament, resulting in severe pain, significant swelling, and major loss of function. By assessing for minor loss of function, the nurse can differentiate between the two grades of sprains. Choices A, B, and C are incorrect because they do not specifically differentiate between a grade 2 and grade 3 sprain based on the level of functional impairment.

Correct Answer: C

Rationale: The correct answer is C: Greater freedom of movement. External fixation devices provide this advantage by allowing for adjustability and mobility of the affected limb. This is crucial for rehabilitation and preventing joint stiffness. Choice A (Faster healing time) is not specific to external fixation devices and can vary case by case. Choice B (Allowance for immediate weight bearing) may not always be recommended due to the complexity of the injury. Choice D (Pain reduction) is not a major advantage of external fixation devices, as they primarily focus on stabilizing fractures rather than directly reducing pain.

Correct Answer: A

Rationale: The correct answer is A: IgA. IgA is found in breast milk and plays a crucial role in providing immunity to the infant. It helps protect against infections in the digestive and respiratory tracts. IgM is primarily found in the bloodstream, IgD is mainly on the surface of B cells, and IgG is transferred from the mother to the fetus during pregnancy. IgA is the specific immunoglobulin class present in breast milk, making it the correct choice.

Correct Answer: C

Rationale: The correct answer is C: IL-10. IL-10 is known to polarize activated T cells towards a TH2 subset by suppressing TH1 cytokine production. IL-12 (A) promotes TH1 differentiation, IL-2 (B) supports T cell proliferation, and IL-5 (D) is involved in eosinophil activation and differentiation, not in polarizing T cells towards a TH2 subset.