Which cells are key to immune memory?

Correct Answer: B

Rationale: Memory lymphocytes provide immune memory; neutrophils , macrophages , and eosinophils are innate.

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).

Correct Answer: C

Rationale: Paracortex venules are lined with cuboidal (high) endothelium ; it's T-lymphocyte-rich, not B , and not between spleen structures or lined with plasma cells .