ATI RN
PAL Histology Lymphatic System Lab Practical Question 1 Questions
Question 1 of 5
Choose the correct statement about pharyngeal tonsil:
Correct Answer: B
Rationale: Pharyngeal tonsil has pseudostratified columnar epithelium with goblet cells ; it lacks crypts , is in nasopharynx , protects respiratory system .
Question 2 of 5
What is the function of CD4 and CD8 co-receptors?
Correct Answer: C
Rationale: CD4/CD8 enhance TCR signaling via CD3 ; they stabilize MHC binding (A indirectly), not antigen binding .
Question 3 of 5
Which cells in the thymus examine T cells for MHC restriction and tolerance of self during positive selection?
Correct Answer: C
Rationale: Cortical thymic epithelial cells test T cells for MHC restriction in positive selection ; medullary cells handle negative selection.
Question 4 of 5
Which type of immunoglobulin molecule is passed on to nursing infants in breast milk?
Correct Answer: C
Rationale: IgA is in breast milk for infant gut immunity; IgG crosses the placenta, IgM and IgE don't transfer via milk.
Question 5 of 5
An infant with recurrent bacterial and fungal infections is suspected to have an immunodeficiency disease. Within two days after exposure to a pathogen, the organisms have proliferated to dangerous levels requiring immediate systemic antibiotic treatment. It is unlikely that this infant has a defect in B or T lymphocyte responses to the infection because:
Correct Answer: D
Rationale: Adaptive responses (B/T cells) take days, so rapid failure suggests innate defects; bacteria/fungi need adaptive immunity , transport occurs , spleen aids but isn't sole .