ATI RN
Pediatric Immunization Practice Questions Questions
Question 1 of 5
Lymphocyte passage (diapedesis or transmigration) occurs at the between adjacent endothelial cells then into the tissues.
Correct Answer: C
Rationale: Diapedesis occurs at adherens junctions between endothelial cells.
Question 2 of 5
In which of the following developmental stages of T cells are surface molecules CD4 and CD8 NOT expressed?
Correct Answer: A
Rationale: Double-negative (DN) cells lack both CD4 and CD8, unlike DP (both expressed) and SP (one expressed) stages.
Question 3 of 5
Activation of a T cell requires ___. Following activation, the T cell proliferates and differentiates into ___, then moves into peripheral tissues and other organs.
Correct Answer: D
Rationale: T-cell activation requires both MHC-antigen recognition and costimulation, leading to effector cell differentiation.
Question 4 of 5
What is the immunologic consequence of mutation in CD40L (CD154)?
Correct Answer: C
Rationale: CD40L mutation causes X-linked hyper-IgM syndrome, impairing class switching from IgM.
Question 5 of 5
The route of antigen processing (cytosolic versus vesicle bound) determines whether an antigen is presented by MHC class II molecules to a TCR on a CD4+ helper (TH) cell, or by major histocompatibility complex (MHC) class I molecules to a TCR on a CD8+ cytotoxic T cell.
Correct Answer: A
Rationale: Cytosolic antigens go to MHC I (CD8+), vesicle-bound to MHC II (CD4+). This is true.