Which of the following is a part of neuron?

Correct Answer: D

Rationale: A neuron consists of three main parts: the axon (A), which transmits signals away from the cell body; the cell body (B), which contains the nucleus and maintains the neuron; and dendrites (C), which receive signals. Since all listed options are parts of a neuron, 'all of the above' (D) is correct.

Correct Answer: C

Rationale: Optic nerve lesions cause unilateral blindness (not homonymous hemianopia, ruling out A), optic chiasm lesions cause bitemporal hemianopia (not unilateral blindness, ruling out B). Visual evoked potentials (C) test the visual pathway’s integrity, while D is vague and incomplete. C is correct.

Correct Answer: B

Rationale: Pain uses both myelinated (A-delta) and unmyelinated (C) fibers (not only myelinated, ruling out A). Perception occurs in the cortex (B, correct), referral is visceral to somatic (C is correct but less central), and cordotomy relief is temporary (not long-lasting, D). B is the most definitive.

Correct Answer: D

Rationale: Position sense (proprioception) is tested by joint movement, not tuning fork (A, vibration). It travels via dorsal columns, not spinothalamic (B). Pyramidal lesions (C) affect motor, not sensory. Sensory ataxia (D) from dorsal column loss impairs position sense. D is correct.

Correct Answer: A

Rationale: Lower motor neuron disease causes wasting (A), weakness, and hyporeflexia, not hypertonia (B), hyperreflexia (C), or clonus (D, upper motor signs). A is correct.