Regarding posterior white column medial lemniscal pathway, choose the WRONG statement:

Correct Answer: B

Rationale: Fasciculus cuneatus transmits information coming from areas inferior to T6 . The fasciculus cuneatus carriproprioception, vibration, and fine touch from the upper body (above T6), while the fasciculus gracilis handlbelow T6. Choice A is true (faster myelinated fibers). Choice C is correct (ipsilateral loss below lesion). Choice D is accurate (excludfree nerve endings, used by spinothalamic). Thus, B misattributcuneatus function, making it the wrong statement and the correct answer.

Correct Answer: D

Rationale: Spinotectal. The spinotectal tract carriafferent sensory information (e.g., pain, touch) from the spinal cord to the tectum (superior colliculus) in the midbrain, contributing to spinovisual reflexlike head/eye turning toward stimuli. Choice A (anterior spinothalamic) is for crude touch to thalamus. Choice B (lateral spinothalamic) is for pain/temperature. Choice C (posterior spinocerebellar) is for unconscious proprioception to cerebellum. Thus, D correctly identifithe spinotectal tracts role, making it the right answer.

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.