With regard to the thymic medulla (ANAT2020 only): It is supported by a reticular framework.

Correct Answer: A

Rationale: The thymic medulla is supported by epithelioreticular cells forming a reticular framework.

Correct Answer: C

Rationale: The spleen's capsule contains vessels, nerves, muscle , dense C.T. , and trabeculae ; it's thick at the hilum, not thin (C is incorrect).

Correct Answer: B

Rationale: Thymus is located in the thoracic cavity behind the sternum.

Correct Answer: D

Rationale: Spleen destroys RBCs , stores blood/platelets , forms fetal blood ; lymph filtration is a lymph node function .

Correct Answer: D

Rationale: Double-positive thymocytes that fail to recognize MHC undergo apoptosis during negative selection; they don't proliferate or differentiate (B, C) without MHC interaction.