Spiral Organ of Corti Flashcards

Questions and Answers

What is another name for the organ of Corti?

Auditory canal

Cochlear organ

Spiral organ (correct)

Vestibular organ

What is the organ of Corti composed of?

Mostly epithelial structures that occupy the length and breadth of the basilar membrane.

What two classifications can the cells of the organ of Corti fall into?

Receptive or supportive cells.

Inner and outer pillar cells are also known as?

Rods of Corti Signup and view all the answers

What is the tunnel of Corti formed by?

The rods of Corti. Signup and view all the answers

Where is cortilymph found?

In the inner tunnel of Corti. Signup and view all the answers

What is the floor of the tunnel of Corti formed by?

The bases of the pillar cells and by the basilar membrane. Signup and view all the answers

What are the inner hair cells supported by at their bases?

Bodies of the phalangeal cells. Signup and view all the answers

What are the inner hair cells supported by at their apexes?

Phalangeal processes. Signup and view all the answers

Where do the inner rods of Corti rest?

At the point of junction of the tympanic lip of the osseous spiral lamina and the basilar membrane. Signup and view all the answers

Are the walls of the inner tunnel of Corti solid?

No, they have slit-like spaces. Signup and view all the answers

What is the reticular membrane?

A delicate net-like structure lying over the spiral organ. Signup and view all the answers

What is the function of the reticular membrane?

It lends support to the apexes of the hair cells. Signup and view all the answers

What are the receptor cells of hearing?

The inner and outer hair cells. Signup and view all the answers

How are the inner and outer hair cells different?

In shape, in arrangements of hairs or stereocilia, and in nerve supply. Signup and view all the answers

How many rows of inner hair cells are there?

Single row. Signup and view all the answers

How many rows of outer hair cells are there?

Three rows. Signup and view all the answers

What is the number of inner hair cells?

<ol start="3500"> <li></li> </ol> Signup and view all the answers

What is unique about the main body of the Deiters cell?

Main body is cylindrical; its shape modifies to form a cup that snugly accommodates the basal end of an outer hair cell. Signup and view all the answers

What is the tectorial membrane?

A delicate structure connected to the epithelial covering of the vestibular lip of the limbus. Signup and view all the answers

How would you describe the physical characteristics of the tectorial membrane?

Semitransparent, gelatinous structure. Signup and view all the answers

Is the tectorial membrane cellular or non-cellular?

Non-cellular. Signup and view all the answers

What are the three separate substrata of the tectorial membrane?

Cover net, fibrous main body, homogeneous basal layer (Hardesty's membrane). Signup and view all the answers

What is the current estimated number of hair cells?

About 3500 inner hair cells and about 12,000 to 20,000 outer hair cells. Signup and view all the answers

What are the physical properties of the stereocilia?

Larger in diameter at upper free ends, and outer row of cilia are the longest. Signup and view all the answers

What surrounds the entire hair cell?

Plasma membrane. Signup and view all the answers

What features do the outer hair cells share with inner hair cells?

Capped with cuticular membrane, contain a basal body, and entire cell and its cilia are covered with well-defined plasma membrane. Signup and view all the answers

What are the shapes of outer hair cells?

Cylindrical with rounded nucleated base. Signup and view all the answers

Which stereocilia is longer than all others on outer hair cell?

Outer stereocilia. Signup and view all the answers

What is the result of these stereocilia connections?

Possibly excitation with stretching and inhibition with relaxation. Signup and view all the answers

What protein is possibly found in stereocilia?

Actin. Signup and view all the answers

Study Notes

Organ of Corti Overview

Another name for the organ of Corti is the spiral organ.
Located on the vestibular surface of the basilar membrane, it contains sensory cells essential for hearing.

Composition and Structure

The organ of Corti consists of epithelial structures that span the basilar membrane.
Cells within the organ of Corti are classified as either receptive (sensory) or supportive cells.

Pillar Cells

Inner and outer pillar cells are known as rods of Corti, providing structural support within the organ.
The rods of Corti create the triangular tunnel of Corti, which contains cortilymph.

Cell Types and Functions

Inner hair cells are arranged in a single row and supported by phalangeal cells, which connect to the basilar membrane.
Outer hair cells are arranged in three rows, stabilized by a network of cells at their bases.

Supporting Structures

The vestibular lip features a distinctive epithelium, visible as "auditory teeth" from above.
The phalangeal cells consist of a main body and a process that extends towards the hair cells.
The reticular membrane, a delicate structure, supports the apex of hair cells and is formed from phalangeal cell components.

Cell Organization

Inner hair cells number around 3,500 and are positioned between inner phalangeal cells and inner rods.
Outer hair cells number between 12,000 and 20,000 and are organized in a V or W shape, with their length increasing from base to apex of the cochlea.

Stereocilia Structure

Stereocilia, hair-like structures on hair cells, vary in length and diameter, enhancing their mechanotransduction capability.
Stereocilia are connected by fine fibrils, allowing them to bend and move as a unit in response to sound.

Tectorial Membrane Properties

The tectorial membrane sits above the hair cells, is gelatinous, and serves a mechanical role without cellular components.
Comprised of three layers: cover net, fibrous main body, and homogeneous basal layer (Hardesty's membrane).

Specialized Cells

Cells of Deiters provide support to outer hair cells and are shaped to accommodate their bases.
Cells of Henson reside adjacent to the outer rows of Deiter’s cells and form the upper limit of the outer tunnel.

Unique Features

The habenula perforate is the area where phalangeal cells contact the spiral lamina directly, crucial for cellular support.
The microstructure of the inner hair cells ensures consistent height, while stereocilia length varies, with outer stereocilia being the longest.

Endolymph and Physiology

The stria vascularis is essential for endolymph secretion and maintaining ionic balance within the cochlea.
Hair cells act as the primary receptors for hearing, with inner and outer hair cells differing in shape, arrangement of stereocilia, and neural connections.

Quantitative Details

There are approximately 4,000 outer rods of Corti and 6,000 inner rods, with significant spatial variations throughout the cochina.

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Description

Test your knowledge about the spiral organ of Corti with these flashcards! This quiz covers essential terms and definitions related to the structure and function of this important hearing organ. Perfect for students studying anatomy or audiology.