The cerebral aqueduct links the:

Correct Answer: C

Rationale: The cerebral aqueduct (in the midbrain) connects the third ventricle to the fourth ventricle, allowing CSF flow. Lateral ventricles connect to the third via the interventricular foramina.

Correct Answer: A

Rationale: Signal transmission along the axon (A) is electrical due to action potentials (changes in membrane potential). Between neurons (B), transmission is typically chemical via synapses. 'Never' (C) and 'always' (D) are incorrect, as transmission is context-dependent—electrical within a neuron, chemical between neurons.

Correct Answer: D

Rationale: The basal ganglia do not primarily control balance (A) or equilibrium (B), which are cerebellar functions, nor conjugate eye movement (C), which involves brainstem nuclei. They play a key role in initiating and modulating voluntary movements (D), as seen in disorders like Parkinson’s disease where initiation is impaired. Power is not typically lost in basal ganglia disease (e.g., rigidity in Parkinson’s), but this option was omitted.

Correct Answer: C

Rationale: Theta waves are 4-7 Hz (not 1-3, ruling out A), alpha waves appear by 3-4 months (not after 4 years, ruling out B), sensory memory recall lasts seconds (C is true), and REM sleep cycles are ~10-20 minutes, not 30 (D). C is correct.

Correct Answer: A

Rationale: C6/C7 compression affects the triceps reflex (C7, A, correct) ipsilaterally. Hyperalgesia below (B) suggests spinothalamic damage, but ipsilateral pain loss is more likely. Vibration sense (C) is contralateral via dorsal columns, but incomplete here. Knee jerk (L3-L4, D) is unaffected. A is most specific.