Impulses generated in the taste buds of the tongue reach the cerebral cortex via the:

Correct Answer: A

Rationale: Taste travels via cranial nerves (VII, IX, X) to the medulla, then thalamus (A, correct), and cortex. Internal capsule (B) is a pathway, trochlear (C) is eye movement, and hypoglossal (D) is tongue movement. A 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.

Correct Answer: B

Rationale: Ligand-gated channels open when a neurotransmitter (ligand) binds to them, allowing ions to flow. Voltage-gated channels respond to depolarization, not ligand-gated ones.