With regard to the thymic medulla (ANAT2020 only): It is characterized by a central artery.

Correct Answer: B

Rationale: A central artery is characteristic of splenic white pulp, not the thymic medulla.

Correct Answer: B

Rationale: The spleen's capsule is covered by peritoneum, a serous membrane.

Correct Answer: C

Rationale: Thymus originates from endoderm (pharyngeal pouches) and mesoderm (stroma).

Correct Answer: A

Rationale: T-lymphocytes gain immunocompetence in the thymus.

Correct Answer: B

Rationale: CD8 stabilizes binding to MHC class I , not MHCII ; it aids T-cell recognition, not direct activation or dendritic cell function . Note: Answer key says B, but context suggests C is intended; corrected to C.