ATI RN
Immune System Quiz Questions Questions
Question 1 of 5
What is the function of cytokines produced by macrophages?
Correct Answer: C
Rationale: Cytokines from macrophages signal and coordinate immune responses ; they don't destroy pathogens directly , form vesicles , or primarily affect blood flow .
Question 2 of 5
What is the function of CTLA-4 on T cells?
Correct Answer: B
Rationale: CTLA-4 inhibits T-cell activation by competing with CD28 ; it doesn't activate (A, C) or target B7 directly .
Question 3 of 5
Why do tissues swell during inflammation?
Correct Answer: C
Rationale: Increased capillary permeability during inflammation allows fluid leakage, causing swelling ; bacteria , blood cells , and pus contribute but aren't the primary cause.
Question 4 of 5
The antigen receptor on a T cell recognizes a degraded fragment of a protein (i.e., a peptide) bound to a specialized cell surface peptide-binding receptor called an MHC molecule. One key aspect of this system is that the peptides displayed on MHC molecules can be derived from intracellular proteins. This mode of antigen recognition is particularly important in allowing the adaptive immune response to detect infections by:
Correct Answer: B
Rationale: MHC presentation of intracellular peptides detects viruses/protozoa ; extracellular pathogens (C, D) or helminths are less MHC-dependent.
Question 5 of 5
Macrophages express multiple types of receptors on their surface that stimulate phagocytosis of microbes, leading to pathogen internalization and destruction. Many of these receptors, such as Dectin-1, rely on direct recognition of a PAMP on the pathogen surface. However, some receptors that stimulate phagocytosis rely on soluble factors (not associated with the phagocyte membrane) to identify and mark the pathogen for uptake by the phagocyte. One such receptor is:
Correct Answer: D
Rationale: Complement receptors bind soluble C3b; mannose , scavenger , and lectin receptors bind PAMPs directly.