The thoracic duct typically ends at the junction of the left subclavian vein and the left.

Correct Answer: B

Rationale: The thoracic duct ends at the junction of the left subclavian vein and left internal jugular vein, a key lymphatic-venous connection.

Correct Answer: B

Rationale: Lingual tonsils are multiple masses at the tongue's base.

Correct Answer: C

Rationale: Lymphatic vessels have bicuspid valves, giving a beaded appearance ; they have thin walls and variable diameters.

Correct Answer: A

Rationale: T-cell receptors are exclusive to adaptive immunity (T cells); TLRs , mannose receptors , and complement receptors are on innate immune cells like macrophages.

Correct Answer: C

Rationale: Hyperactivation is the highest macrophage activation state, beyond resting or basic activation ; MHC II upregulation is a feature, not a state.