Know your Ear (Part2) – How you hear and What keeps the balance – 3D CT images of inner ear

The inner ear

The inner ear is the most complicated component of the auditory system located into a tiny space of the hardest petrous part of the temporal bone and inaccessible to direct examination or clinical manipulation. The inner ear comprise of three intimately related structures – the cochlea (spiral tube), three semicircular canals and the vestibule (labyrinth).

The cochlea is directly responsible for hearing and contains nerves responsible for converting energy vibrations within the inner ear fluid into nerve impulses which can be transmitted to the brain. While the vestibule (Bony and membranous labyrinth) and semicircular canals function to maintain balance or equilibrium.

Functions of the inner ear

Hearing

The vibrations are finally interpreted as sound in the brain after being transmitted and transformed into nerve signals by the cochlea (snail shaped component of the inner ear). This is due to the connectivity of the oval window of the inner ear to the edge of the stapes. When the stapes vibrates, they always transmit the sound vibrations to the inner ear.

Balance and Equilibrium

The other important function of the ear is to help maintain balance. Oriented at the right angles to each other are three semicircular canals of the inner ear. Whenever the head is turned or change position, the resulting movement of fluids within these canals help the brain to identify or detect the extent of movement and positioning of the head.

In response to gravity, another part of the inner ear sends information to the brain when the head is held still in a stagnant position.

(3D CT images(VR) Courtesy :Vergin G.S and Dr.Asha FRCR, Travancore Scan, Trivandrum)

*Please donot copy the 3D CT images without prior permission

Dr Paulose is an ENT Consultant Plastic and Laser Surgeon with over 35 years of experience covering in Ear, Nose and Throat procedures, specializing in Laser Surgery and conventional medicine across India, U.K. and Middle East. He is currently engaged with the Jubilee Hospital, in Kerala, India.