Question

multiple choice question

which are embedded into the otolithic membrane?

kinocilia
villi
microvilli

Explanation:

Identify the structures of the macula

Using the Otolithic Membrane Mechanics knowledge point, we analyze the anatomical components of the maculae in the vestibule (the utricle and saccule). The macula is the sensory receptor organ for detecting linear acceleration and gravity. It consists of a layer of hair cells covered by a gelatinous layer called the otolithic membrane.

Analyze the hair cell projections

The apical surface of each hair cell features specialized projections:

• Stereocilia (which are specialized microvilli-like structures, but are specifically referred to as stereocilia in sensory transduction).
• A single, taller true cilium called the kinocilium.

These projections (both stereocilia and the kinocilium) extend upward from the hair cells and are physically embedded into the overlying gelatinous otolithic membrane.

Evaluate the given options

• Kinocilia: These are the true cilia of the vestibular hair cells that project directly into and are embedded within the otolithic membrane.
• Villi: These are finger-like projections of the mucosa found in the small intestine, unrelated to the inner ear.
• Microvilli: While stereocilia are structurally modified microvilli, standard microvilli are found on the apical surface of absorptive epithelial cells (such as in the gut or kidneys) and are not embedded in an otolithic membrane.

Answer:

• Kinocilia (Correct answer)
• Villi
• Microvilli