Select the correct statement regarding the medial lemniscus:

Correct Answer: C

Rationale: It is concerned with proprioception (muscle-joint sense) . The medial lemniscus, formed by decussating fibers from the nucleus gracilis and cuneatus in the medulla, carriproprioception, vibration, and fine touch to the thalamus (VPL), then cortex. Choice A is wrong (begins in medulla, not spinal cord). Choice B is false (spinothalamic tracts are separate). Choice D is incorrect (ends in thalamus, not cortex directly). Thus, C accurately describits role, making it correct.

Correct Answer: B

Rationale: Massage applied to the skin over a painful joint may reduce pain sensitivity . The gate control theory posits that non-painful input (e.g., touch via large A-beta fibers) can inhibit pain signals (A-delta, C fibers) at the spinal cords dorsal horn via interneurons, reducing pain perception. Massage activatA-beta fibers, supporting this. Choice A is wrong (small fibers transmit pain). Choice C is incorrect (A-delta/C fibers increase pain). Choice D is false (large fiber loss increaspain). Thus, B aligns with the theory, making it correct.

Correct Answer: A

Rationale: contains 2nd order neurons from clarks nucleus that originate from the lower limbs . The dorsal spinocerebellar tract carriunconscious proprioception from lower limbs via second-order neurons in Clarknucleus (T1-L2), entering the cerebellum through the inferior peduncle. Choice B is wrong (upper limbs use cuneocerebellar tract). Choice C is incomplete. Choice D is false (A is correct). Thus, A accurately describthe tract, making it correct.

Correct Answer: D

Rationale: 55% of its fibers synapse in the upper cervical region . The anterior corticospinal tract, uncrossed, acts on axial muscl, passthrough the pons basilar part and midbrain pedunculi , but only about 10-20% remain uncrossed, with most synapsing lower, not 55% in cervical. Thus, D overestimatcervical synapses, making it the wrong statement and the correct answer.

Correct Answer: D

Rationale: In front of the central sulcus. Fine hand movements are controlled by the primary motor cortex, in the precentral gyrus, anterior to the central sulcus. Choice A (temporal gyrus) is for audition. Choice B (postcentral) is sensory. Choice C (medial brain) includleg areas. Thus, D correctly locatthe hand motor area, making it correct.