Question

The gelatinous membrane covering the sensory hair cells of the ear is known as (a) Reissner's membrane (b) tectorial membrane (c) basilar membrane (d) neuro-sensory

Short answer

The correct answer is (b) tectorial membrane.

Step-by-step solution

Identify the correct membrane

Review the function of the membranes listed and match them with the sensory hair cells of the ear. The gelatinous membrane that covers the hair cells in the organ of Corti is the tectorial membrane.

Eliminate incorrect options

Reissner's membrane separates two fluid-filled spaces in the cochlea and is not in direct contact with hair cells. The basilar membrane supports the organ of Corti but is not the gelatinous membrane covering the hair cells. 'Neuro-sensory' is not a relevant term in the context of ear anatomy regarding a specific membrane.

Confirm the correct answer

Only the tectorial membrane fits the description of the gelatinous covering of the sensory hair cells in the ear. Thus, option (b) tectorial membrane is the correct answer.

Key concepts

Sensory Hair Cells

The sensory hair cells in the inner ear play a crucial role in our ability to hear and balance. These specialized cells are located within the organ of Corti, which is situated on the basilar membrane in the cochlea.

Each sensory hair cell has a set of tiny hair-like projections called stereocilia that protrude from its top surface. These stereocilia are pivotal; when sound waves cause the fluid inside the cochlea to move, the stereocilia bend. This bending opens mechanically gated ion channels, which leads to the generation of an electrical signal that the brain interprets as sound.

Function of Sensory Hair Cells

Sensory hair cells are categorized into two types: inner and outer hair cells. Inner hair cells are primarily responsible for converting sound vibrations into electrical signals, whereas outer hair cells function to amplify and fine-tune these vibrations.

This entire process is delicate and requires protection, a role fulfilled by the tectorial membrane, which gently rests atop the hair cells. Without properly functioning hair cells, a person may experience hearing loss or balance issues, emphasizing their significance in the sensory system.

Ear Anatomy

Ear anatomy can be divided into three main sections: the outer ear, middle ear, and inner ear. Each area has a distinct structure and function that collectively allows us to hear and maintain equilibrium.

The outer ear includes the visible part called the auricle, and the ear canal, which leads to the eardrum. The middle ear houses the ossicles, three tiny bones named the malleus, incus, and stapes that transfer sound vibrations from the eardrum to the inner ear.

The Inner Ear

The inner ear consists of the cochlea, which is responsible for hearing, and the vestibular system, which controls balance. Within the coiled chamber of the cochlea, the organ of Corti and its sensory hair cells are seated onto the basilar membrane, ready to translate sound waves into nerve impulses.

In understanding ear anatomy, it becomes evident how the design facilitates the transformation of sound from air vibrations outside the body into the electrical signals our brains can interpret.

Organ of Corti

The organ of Corti, found within the cochlea of the inner ear, represents the core of our hearing apparatus. This microscopic structure contains rows of sensory hair cells that detect sound vibrations.

The organ of Corti sits atop the basilar membrane along the entire length of the spiraled cochlea. It is tuned along its length to different frequencies, with high frequencies being detected at the base and lower frequencies at the apex.

Importance of the Organ of Corti

Crucial for converting mechanical sound vibrations into electrical signals, the health and functioning of the organ of Corti are essential for clear hearing. It works in harmony with the tectorial membrane, which, by making contact with the hair cells, plays a part in the signal transduction process that ultimately leads to hearing.

The specifics of how the organ of Corti operates, including the processes of mechanotransduction and the role of the tectorial membrane, are a testament to the complexity of the human body's sensory systems and our remarkable ability to detect and interpret a wide range of sounds.