What is stria vascularis?
The stria vascularis is a specialized region of the inner ear that is responsible for producing and maintaining the endolymph, the fluid that fills the scala media. The scala media is one of the three fluid-filled chambers of the cochlea, the hearing organ.
What is the role of the stria vascularis in hearing?
The endolymph is essential for hearing because it provides the electrical potential that drives the hair cells in the organ of Corti, the sensory cells that convert sound waves into electrical signals. The stria vascularis produces the endolymph by actively pumping potassium ions into the scala media.
This creates a high concentration of potassium ions in the endolymph, which creates an electrical potential across the hair cells. When sound waves cause the basilar membrane, the structure that supports the organ of Corti, to vibrate, the hair cells are bent and send electrical signals to the brain.
Where is stria vascularis?
The stria vascularis is located on the lateral wall of the cochlea, the hearing organ. It is a thin, ribbon-like structure that runs along the entire length of the cochlea.
What are the cells of stria vascularis?
The stria vascularis is composed of three types of cells: marginal cells, intermediate cells, and basal cells.
- Marginal cells: Marginal cells are the most abundant cells in the stria vascularis. They are responsible for actively pumping potassium ions into the scala media.
- Intermediate cells: Intermediate cells are located between the marginal cells and the basal cells. They are thought to play a role in maintaining the ion composition of the endolymph.
- Basal cells:Basal cells are the least abundant cells in the stria vascularis. They are thought to provide support for the other cells in the stria vascularis.
Conclusion
The stria vascularis is a vital part of the inner ear and plays an essential role in hearing. It produces and maintains the endolymph, the fluid that fills the scala media, and provides the electrical potential that drives the hair cells in the organ of Corti. If the stria vascularis is damaged, it can lead to hearing loss.