With regard to the thymic medulla (ANAT2020 only): It is characterized by Hassall's (thymic) corpuscles.

Correct Answer: A

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

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 .

Correct Answer: A

Rationale: NK cells are innate immune cells from a lymphoid progenitor; they're not adaptive (C, D) and not myeloid-derived .