Which organ traps gut pathogens?

Correct Answer: C

Rationale: Peyer's patches trap gut pathogens; spleen filters blood, thymus matures T cells, nodes filter lymph.

Correct Answer: A

Rationale: Hassall's corpuscles are a distinctive feature of the thymic medulla.

Correct Answer: B

Rationale: Small to medium lymphatic vessels have thin walls to facilitate lymph flow, but diameter and lumen size vary, so not all apply.

Correct Answer: D

Rationale: The spleen is the largest single intra-abdominal lymphatic organ; the liver is larger but not lymphatic.

Correct Answer: C

Rationale: Lingual tonsils are lined by stratified squamous epithelium, not pseudostratified (A is incorrect); adenoids refer to pharyngeal tonsils ; they have crypts and are non-capsulated (C is correct).