Nokea
Secondary lymphoid tissues are where:
- A. Lymphocyte precursors become mature
- B. Inflammation occurs during re-infection with a given pathogen
- C. Lymphocytes become activated by antigen
- D. Gene rearrangement takes place
Correct Answer: C
Rationale: The correct answer is C because secondary lymphoid tissues, like lymph nodes and spleen, are where lymphocytes encounter antigens and become activated. This process leads to the proliferation and differentiation of lymphocytes, enabling them to mount an immune response against specific pathogens. Choices A, B, and D are incorrect because A pertains to primary lymphoid tissues, B describes a localized immune response, and D refers to the process of gene rearrangement that occurs in the primary lymphoid tissues during lymphocyte development.
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Therapy for autoimmune diseases does NOT include
- A. Immuno-suppressive drugs such as cortisone
- B. Aspirin
- C. Anti-TNF therapy
- D. Anti-CD20
Correct Answer: E
Rationale: Rationale for Correct Answer (E):
E: Surgery is the correct answer. Surgery is not typically used as a primary therapy for autoimmune diseases. Autoimmune diseases are usually treated with medications such as immuno-suppressive drugs (A), anti-inflammatory drugs (B), and targeted therapies like anti-TNF (C) and anti-CD20 (D) to manage symptoms and control the immune response. Surgery is only considered in specific cases when other treatments have failed or for complications related to the autoimmune disease. Therefore, surgery is not a standard therapy for autoimmune diseases.
Summary of Incorrect Choices:
A: Immuno-suppressive drugs like cortisone are commonly used in autoimmune disease treatment.
B: Aspirin is an anti-inflammatory drug that can help manage symptoms in some autoimmune diseases.
C: Anti-TNF therapy targets specific molecules involved in the immune response in autoimmune diseases.
D: Anti-CD20 therapy targets B cells to modulate the immune response in autoimmune diseases.
Carpal tunnel syndrome (CTS) is caused when the carpal tunnel compresses which location?
- A. Radial artery
- B. Brachial artery
- C. Median nerve
- D. Ulnar nerve
Correct Answer: C
Rationale: The correct answer is C: Median nerve. Carpal tunnel syndrome occurs when the median nerve is compressed within the carpal tunnel in the wrist. This compression leads to symptoms like numbness, tingling, and weakness in the hand and fingers. The other choices are incorrect because the radial artery (A) and the brachial artery (B) are blood vessels, not nerves. The ulnar nerve (D) runs along a different path in the arm and is not involved in carpal tunnel syndrome.
What happens when immune complexes are not cleared in Type III hypersensitivity?
- A. They activate T cells
- B. They deposit in tissues, causing inflammation
- C. They are phagocytosed by macrophages without effects
- D. They suppress antibody production
Correct Answer: B
Rationale: The correct answer is B because when immune complexes are not cleared in Type III hypersensitivity, they deposit in tissues, activating complement cascades and causing inflammation. This leads to tissue damage and the recruitment of inflammatory cells.
A: Immune complexes do not directly activate T cells in Type III hypersensitivity.
C: Phagocytosis of immune complexes can lead to cell activation and inflammation.
D: Immune complexes do not suppress antibody production in Type III hypersensitivity.
What triggers the release of mediators from mast cells during Type I hypersensitivity?
- A. Cross-linking of IgE molecules on the mast cell surface
- B. Activation of complement proteins
- C. Binding of IgG to antigen
- D. Phagocytosis of allergens
Correct Answer: A
Rationale: The correct answer is A. Cross-linking of IgE molecules on the mast cell surface triggers the release of mediators during Type I hypersensitivity. When allergens bind to IgE antibodies on mast cells, it leads to cross-linking of IgE molecules, causing the mast cell to release histamine and other inflammatory mediators. This process initiates the allergic response.
Explanation for incorrect choices:
B: Activation of complement proteins does not directly trigger mast cell degranulation in Type I hypersensitivity.
C: Binding of IgG to antigen is characteristic of Type II and Type III hypersensitivity reactions, not Type I.
D: Phagocytosis of allergens does not directly stimulate mast cells to release mediators in Type I hypersensitivity.
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.