Nokea
Which of the following are not typically found within secondary lymphoid tissues?
- A. naïve lymphocytes
- B. Hematopoietic stem cells
- C. Dendritic cells
- D. Antigen
Correct Answer: B
Rationale: Correct Answer: B - Hematopoietic stem cells are not typically found within secondary lymphoid tissues because they are located in the bone marrow where they give rise to various blood cells. In contrast, secondary lymphoid tissues like lymph nodes and spleen primarily consist of mature immune cells and support immune responses. Naïve lymphocytes (A), dendritic cells (C), and antigens (D) are commonly found in secondary lymphoid tissues as they play crucial roles in the immune response.
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If you were to observe the activity of methylated DNA, you would expect it to
- A. be unwinding in preparation for protein synthesis.
- B. be replicating nearly continuously.
- C. have turned off or slowed down the process of transcription.
- D. induce protein synthesis by not allowing repressors to bind to it.
Correct Answer: C
Rationale: The correct answer is C because methylation of DNA typically results in the inhibition or slowing down of transcription. Methylated DNA attracts proteins that bind to it, preventing transcription factors from accessing the DNA and initiating transcription. This interference with the transcription process leads to gene silencing or reduced gene expression.
A: DNA unwinding in preparation for protein synthesis is unrelated to DNA methylation.
B: Continuous replication is not a typical consequence of DNA methylation.
D: Methylation does not directly induce protein synthesis but rather affects transcription by influencing gene expression.
Which hypersensitivity type is mediated by T cells?
- A. Type I
- B. Type II
- C. Type III
- D. Type IV
Correct Answer: D
Rationale: The correct answer is D: Type IV hypersensitivity. This type is mediated by T cells, specifically CD4+ helper T cells and CD8+ cytotoxic T cells. The process involves antigen-presenting cells activating T cells, leading to a delayed response. Choices A, B, and C involve different mechanisms and are not mediated by T cells. Type I is mediated by IgE antibodies, Type II involves antibody-mediated cell destruction, and Type III involves immune complex deposition. Therefore, Type IV is the only hypersensitivity type directly mediated by T cells.
The nurse is caring for a patient who has had a total hip replacement and is using an abductor wedge. For which finding should the nurse assess?
- A. Muscle spasms
- B. Alteration in peripheral circulation
- C. Compression fracture
- D. Appropriateness of the size of the wedge
Correct Answer: B
Rationale: The correct answer is B: Alteration in peripheral circulation. The abductor wedge can affect blood flow to the legs, leading to potential complications like deep vein thrombosis. The nurse should assess for signs of impaired circulation such as color changes, temperature differences, and peripheral pulses. Muscle spasms (A) may occur due to the surgery but are not directly related to the wedge. Compression fracture (C) is not typically a concern with an abductor wedge. Assessing the appropriateness of the wedge size (D) is important but not as critical as monitoring for alterations in peripheral circulation.
What is a characteristic disease associated with Type III hypersensitivity?
- A. Grave's disease
- B. Goodpasture's syndrome
- C. Systemic lupus erythematosus (SLE)
- D. Contact dermatitis
Correct Answer: C
Rationale: The correct answer is C: Systemic lupus erythematosus (SLE). In Type III hypersensitivity, immune complexes form and deposit in tissues, leading to inflammation and tissue damage. SLE is a classic example of a Type III hypersensitivity reaction where these immune complexes deposit in various organs causing systemic inflammation and damage. Graves's disease (A) is an example of Type II hypersensitivity, where autoantibodies target cell-surface receptors. Goodpasture's syndrome (B) is a Type II hypersensitivity disease affecting the kidneys and lungs. Contact dermatitis (D) is a Type IV hypersensitivity reaction mediated by T cells, not involving immune complexes. Therefore, the correct answer is C as it aligns with the characteristic disease associated with Type III hypersensitivity.
Which of the following is not considered a virulence factor?
- A. Flagella
- B. Effector proteins manipulating host actin cytoskeleton
- C. Toxins
- D. Peptidoglycan
Correct Answer: D
Rationale: The correct answer is D: Peptidoglycan. Peptidoglycan is a structural component of bacterial cell walls and does not directly contribute to the pathogenicity or virulence of the bacterium. Flagella aid in motility and colonization, effector proteins manipulate host cells, and toxins damage host tissues, all of which are virulence factors. Peptidoglycan is essential for maintaining cell shape and integrity but does not directly enhance the ability of the bacteria to cause disease.