Question

what structure is highlighted?

a. external acoustic meatus
b. auditory tube
c. temporal bone
d. vestibulocochlear n. (cn viii)
e. cochlea

Explanation:

Identify the highlighted structure

Using the Auditory System Anatomy knowledge point

• The anatomical diagram shows a cross-section of the human ear, including the outer, middle, and inner ear structures.
• On the right side of the diagram, emerging from the inner ear (specifically from the vestibule and cochlea), there is a prominent nerve highlighted in bright green.
• This nerve is the vestibulocochlear nerve (Cranial Nerve VIII), which carries sensory information for both hearing and balance to the brain.

Evaluate the options

• A. External acoustic meatus: This is the ear canal leading from the auricle to the tympanic membrane, which is not highlighted.
• B. Auditory tube: Also known as the Eustachian tube, this connects the middle ear to the nasopharynx and is located inferiorly, not highlighted.
• C. Temporal bone: This is the surrounding bone structure of the middle and inner ear, shown in beige/brown, not highlighted.
• D. Vestibulocochlear n. (CN VIII): This matches the bright green highlighted nerve bundle exiting the inner ear.
• E. Cochlea: This is the snail-shell-like structure of the inner ear, shown in grey/white, but is not the highlighted green structure itself.

Answer:

• (A) External acoustic meatus
• (B) Auditory tube
• (C) Temporal bone
• (D) Vestibulocochlear n. (CN VIII) (Correct answer)
• (E) Cochlea