Nokea
The intestinal epithelial cells that specialize in the production of antimicrobial peptides are called:
- A. Goblet cells
- B. Enterocytes
- C. Paneth cells
- D. Epithelial stem cells
Correct Answer: C
Rationale: The correct answer is C: Paneth cells. Paneth cells are specialized intestinal epithelial cells located in the small intestine that produce antimicrobial peptides to help defend against pathogens. They play a crucial role in maintaining gut homeostasis. Goblet cells (A) secrete mucus, enterocytes (B) absorb nutrients, and epithelial stem cells (D) are responsible for cell regeneration, but they do not produce antimicrobial peptides like Paneth cells do.
You may also like to solve these questions
A main cytokine produced by CD4+ TH1 cells is
- A. IL-4
- B. IL-10
- C. IL-5
- D. IFN-γ
Correct Answer: D
Rationale: The correct answer is D: IFN-γ. CD4+ TH1 cells are known to primarily produce interferon-gamma (IFN-γ). This cytokine plays a crucial role in promoting cell-mediated immunity and enhancing the activity of macrophages. IL-4 (choice A) is produced by CD4+ TH2 cells and promotes humoral immunity. IL-10 (choice B) is an anti-inflammatory cytokine produced by various immune cells. IL-5 (choice C) is predominantly produced by CD4+ TH2 cells and is involved in eosinophil activation. Therefore, the main cytokine produced by CD4+ TH1 cells is IFN-γ, making choice D the correct answer.
What is characteristic of chronic inflammation?
- A. It may last 2 to 3 weeks.
- B. The injurious agent persists or repeatedly injures tissue.
- C. Infective endocarditis is an example of chronic inflammation.
- D. Neutrophils are the predominant cell type at the site of inflammation.
Correct Answer: B
Rationale: Chronic inflammation occurs when the cause of the initial injury persists or recurs, leading to ongoing tissue damage and repair. Unlike acute inflammation, it involves lymphocytes and macrophages rather than neutrophils.
Which of the following statements concerning Influenza Hemagglutinin (HA) and Neuraminidase (N) is incorrect
- A. Both mutate frequently due to antigenic drift
- B. Function of N is to release new viral particles from infected cells
- C. HA binds to terminal sialic acid on cell surface molecules found on lung epithelial cells
- D. Tamiflu interferes with the attachment of HA to sialic acid
Correct Answer: D
Rationale: The correct answer is D. Tamiflu interferes with the function of Neuraminidase (N), not Hemagglutinin (HA). HA binds to sialic acid on cell surface molecules, not N. N's function is to release new viral particles. Both HA and N undergo antigenic drift. Therefore, choice D is incorrect as it misrepresents the mechanism of action of Tamiflu.
The nurse is counseling a group of individuals over the age of 50 with average risk for cancer about screening tests for cancer. Which screening recommendation should be performed to screen for colorectal cancer?
- A. Barium enema every year
- B. Colonoscopy every 10 years
- C. Fecal occult blood every 5 years
- D. Annual prostate-specific antigen (PSA) and digital rectal exam
Correct Answer: B
Rationale: Colonoscopy every 10 years is recommended for colorectal cancer screening in individuals over 50 with average risk.
What distinguishes NK cells from other lymphocytes?
- A. They are part of adaptive immunity
- B. They do not require prior antigen sensitization
- C. They directly produce antibodies
- D. They phagocytose pathogens
Correct Answer: B
Rationale: The correct answer is B because NK cells do not require prior antigen sensitization to recognize and attack infected cells. This distinguishes them from other lymphocytes, such as T and B cells, which are part of adaptive immunity and require prior exposure to specific antigens. NK cells are part of innate immunity and can directly recognize and kill infected or abnormal cells without prior activation. Choices A, C, and D are incorrect as NK cells are not part of adaptive immunity, do not directly produce antibodies, and do not phagocytose pathogens.