Question

what structure is highlighted?

a. inner phalangeal cells
b. basilar membrane
c. tectorial membrane
d. inner hair cell
e. outer hair cell

Explanation:

Identify the histological section

The image shows a high-magnification histological section of the organ of Corti within the cochlea of the inner ear.

Locate the highlighted structure

Using the Organ of Corti Anatomy and Basilar Membrane Structure knowledge points

• The basilar membrane forms the floor of the cochlear duct supporting the organ of Corti.
• The tectorial membrane is the gelatinous structure projecting over the hair cells.
• A single, flask-shaped cell is highlighted in bright green on the inner (medial) side of the inner tunnel of Corti.

Differentiate the sensory cells

Using the Organ of Corti Anatomy knowledge point

• The single row of flask-shaped cells located on the inner side of the inner tunnel represents the inner hair cells.
• The three rows of cylindrical cells located on the outer side of the tunnel represent the outer hair cells.
• The highlighted cell is a single, flask-shaped cell situated medially, which corresponds to the inner hair cell.

Match with the options

The highlighted structure is the inner hair cell, which corresponds to option D.

Answer:

• A. Inner phalangeal cells
• B. Basilar membrane
• C. Tectorial membrane
• D. Inner hair cell (Correct answer)
• E. Outer hair cell