Nokea
naïve T cells can be found in
- A. Blood
- B. Germinal centers
- C. Mostly in the medullary region of lymph nodes (LN)
- D. In non-lymphoid tissues such as the skin
Correct Answer: A
Rationale: The correct answer is A: Blood. Naïve T cells are circulating in the blood, ready to encounter antigens. They can move to secondary lymphoid organs like lymph nodes. Germinal centers (B) are sites of B cell maturation, not where naïve T cells are primarily found. While some naïve T cells enter lymph nodes (C), they are not mostly located in the medullary region. Naïve T cells can also migrate to non-lymphoid tissues (D), but their primary residence is in the blood.
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A common collaborative problem related to both hyperkalemia and hypokalemia is which potential complication?
- A. Seizures
- B. Paralysis
- C. Dysrhythmias
- D. Acute kidney injury
Correct Answer: C
Rationale: Both hyperkalemia and hypokalemia disrupt cardiac conduction, causing dysrhythmias due to their effects on myocardial cell membrane potentials.
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.
Which of the following is NOT true about the definition of acquired passive immunity
- A. Breast milk is an example
- B. It provides short term protection
- C. Can be transferred through the placenta
- D. It can be used for disease prevention
Correct Answer: E
Rationale: I'm sorry, but the correct answer is not provided in the choices given. Acquired passive immunity refers to the transfer of antibodies from one individual to another. Breast milk, placental transfer, short-term protection, and disease prevention are all characteristics of acquired passive immunity. Therefore, the correct answer is not presented in the options provided.
Thymocytes undergoing positive selection express:
- A. TCR
- B. CD4
- C. CD8
- D. All of the above
Correct Answer: D
Rationale: Thymocytes undergoing positive selection express both CD4 and CD8 co-receptors along with a functional T-cell receptor (TCR). CD4 and CD8 help in recognizing MHC molecules, while TCR is crucial for antigen recognition. Positive selection ensures that thymocytes with a functional TCR that can interact with self-MHC molecules survive. Therefore, the correct answer is D, as thymocytes undergoing positive selection express TCR, CD4, and CD8. Choice A, TCR alone, is incorrect as CD4 and CD8 are also expressed. Choices B and C are incorrect as positive selection involves the expression of both CD4 and CD8, not just one or the other.
Which of the following concerning nosocomial infections is incorrect?
- A. Caused by both Gram-negative and Gram-positive
- B. A common example is represented by Helicobacter pylori
- C. Caused by species that are often antibiotic-resistant
- D. Include infections by Clostridium difficile, a bacterial species that is often part of the commensal flora
Correct Answer: B
Rationale: The correct answer is B because Helicobacter pylori is not typically associated with nosocomial infections. Nosocomial infections are usually caused by bacteria commonly found in healthcare settings, such as Clostridium difficile, which is mentioned in choice D. Choices A, C, and D are correct as nosocomial infections can be caused by both Gram-negative and Gram-positive bacteria, often antibiotic-resistant species, and commensal flora bacteria like Clostridium difficile.