ATI RN
Pediatric Immunization Test Questions Questions
Question 1 of 5
MHC class I has peptides of amino acid residues and is an antigen. MHC class II has peptides of amino acid residues and is an antigen.
Correct Answer: A
Rationale: MHC class I binds 8-11 residue endogenous peptides; MHC class II binds 9-30 residue exogenous peptides.
Question 2 of 5
Presence of the TCR co-receptor molecules (CD4 or CD8) has been estimated to reduce the number of MHC-peptide complexes required to trigger a T-cell response by about:
Correct Answer: D
Rationale: CD4/CD8 co-receptors enhance TCR sensitivity, reducing MHC-peptide complexes needed by ~100-fold.
Question 3 of 5
Major source of antigen-specific protection against viral infection
Correct Answer: D
Rationale: T-cytotoxic cells provide antigen-specific antiviral immunity.
Question 4 of 5
The thymus is the primary site of T-cell development. Which of the following is the correct order arranged from the area with the earliest progenitor cells to the area with the most mature T lymphocytes?
Correct Answer: D
Rationale: T cell maturation progresses from subcapsular zone (progenitors) to cortex to medulla (mature T cells).
Question 5 of 5
Intraepithelial lymphocytes (IEL) act to protect the host against viral and bacterial pathogens encountered in the gut and secrete cytokines. Their predominant phenotype is:
Correct Answer: B
Rationale: IELs are predominantly γδ T cells in the gut.