Sulcus spiralis externus

Sulcus spiralis externus is a structure found in the cochlea of the inner ear. It is a groove that separates the basilar membrane from the vestibular membrane, and is an important part of the auditory system.

Anatomy

The sulcus spiralis externus is located in the cochlea, a spiral-shaped structure in the inner ear. It is a groove that separates the basilar membrane, which supports the organ of Corti, from the vestibular membrane, which separates the scala media from the scala vestibuli.

The sulcus spiralis externus is filled with endolymph, a fluid that plays a crucial role in the process of hearing. The movement of endolymph within the sulcus spiralis externus is what allows us to perceive sound.

Function

The primary function of the sulcus spiralis externus is to facilitate the transmission of sound waves from the outer ear to the inner ear. When sound waves enter the ear, they cause the basilar membrane to vibrate. This vibration is then transmitted to the organ of Corti, which contains hair cells that convert the mechanical vibrations into electrical signals. These signals are then sent to the brain via the auditory nerve, allowing us to perceive sound.

The sulcus spiralis externus also plays a role in maintaining the balance of endolymph within the cochlea. This is important for maintaining the proper functioning of the auditory system.

Clinical significance

Abnormalities or damage to the sulcus spiralis externus can lead to hearing loss or balance disorders. For example, Meniere's disease is a condition that is caused by an excess of endolymph in the cochlea, which can lead to vertigo, tinnitus, and hearing loss.

See also

• Cochlea
• Basilar membrane
• Vestibular membrane
• Organ of Corti
• Scala media
• Scala vestibuli
• Endolymph
• Auditory nerve
• Meniere's disease