How long does all the signaling through the sensory pathway, within the central nervous system, and through the motor command pathway take?

Correct Answer: C

Rationale: Neural signaling, including sensory input, CNS processing, and motor output, occurs in a fraction of a second (milliseconds) due to the speed of action potentials and synaptic transmission.

Correct Answer: C

Rationale: The middle cerebral artery (MCA) is the largest branch of the internal carotid artery, supplying a significant portion of the cerebral cortex (e.g., lateral aspects). The ophthalmic artery is smaller, and the anterior cerebral and striate arteries are not as large.

Correct Answer: C

Rationale: Central cord syndrome (often cervical) damages the central spinal cord, affecting motor (upper limbs > lower) and pain/temperature sensation, while touch sensation (dorsal columns) often remains intact due to its peripheral location.

Correct Answer: D

Rationale: Motor nerve fibers (alpha motor neurons) are large, myelinated, and typically 12-20 micrometers in diameter to ensure fast conduction to muscles. Smaller diameters are for sensory or unmyelinated fibers.

Correct Answer: B

Rationale: The facial nerve (CN VII) doesn’t supply the ciliary ganglion (CN III does via parasympathetic fibers). It supplies facial muscles, buccinator, taste (anterior 2/3 tongue), and the greater petrosal nerve.