Which lymphoid tissue is part of the mucosal immune system?

Correct Answer: C

Rationale: Peyer's patches are mucosal; spleen and nodes are systemic, thymus matures T cells.

Correct Answer: C

Rationale: Macrophages engulf pathogens; antibodies are B cells, killing is T cells, histamine is mast cells.

Correct Answer: B

Rationale: The thymus shrinks post-puberty; it's active in infancy , persists in adulthood , and regresses further in old age .

Correct Answer: B

Rationale: Peyer's patches monitor gut pathogens; blood is spleen, T cells are thymus, antibodies are B cells.

Correct Answer: B

Rationale: Red pulp removes old RBCs; lymphocytes are white pulp, pathogens are macrophages, platelets are stored.