Medullary postural reflexes include:

Correct Answer: A

Rationale: Medullary postural reflexes are controlled by the medulla oblongata and include the positive supporting reaction (A), which maintains stance against gravity. The placing reaction (B) is a midbrain reflex, the tonic neck reflex (C) involves medullary and spinal integration but is not exclusively medullary, and the stretch reflex (D) is a spinal reflex, not primarily medullary.

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.

Correct Answer: B

Rationale: This describes Parkinson’s: rest tremor, bradykinesia, festinant gait, and mask-like face (B, correct). Rigidity (not hypotonia, A), normal power (not severely affected, C), and normal reflexes (not absent, D) are typical. B is correct.