Signs of cerebellar dysfunction include:

Correct Answer: B

Rationale: Cerebellar dysfunction causes past pointing (B, ataxia), hypotonia (not A), wide-based gait (not shuffling, C), and intention tremor (not resting, D). B is correct.

Correct Answer: B

Rationale: The pons (B) is the major input to the cerebellum via the middle cerebellar peduncle, relaying cortical signals for coordination. The midbrain (A) and medulla (C) have lesser roles, and spinal cord (D) input is via inferior peduncles. B is correct.

Correct Answer: D

Rationale: A stroke is caused by disruption of blood to the brain (D), either ischemic (clot) or hemorrhagic (bleed). Meningitis (A) is inflammation, lumbar puncture (B) is diagnostic, and CSF infection (C) is meningitis-related. D is correct.

Correct Answer: D

Rationale: The axon is the part of a neuron that transmits an electrical signal (action potential) to a target cell, such as another neuron or muscle cell, via the synapse. Dendrites receive signals, and the soma (cell body) processes them, but the axon is responsible for transmission.

Correct Answer: C

Rationale: Myelin is primarily composed of lipids (e.g., cholesterol) and proteins (e.g., myelin basic protein), which form the insulating sheath around axons. Carbohydrates and nucleic acids are not major components.