Lend an ear to this organ’s functioning
This is in continuation to the last article focusing on sense organs. Today, let’s discuss how the ear functions.
Hyderabad: This is in continuation to the last article focusing on sense organs. Today, let’s discuss how the ear functions.
The ear
• The ears perform two sensory functions, hearing and maintenance of body balance.
• Anatomically, the ear can be divided into three major sections called the outer ear, the middle ear and the inner ear.
• The outer ear consists of the pinna and external auditory meatus (canal).
• The pinna collects the vibrations in the air which produce sound.
• The external auditory meatus leads inwards and extends up to the tympanic membrane (the ear drum).
• There are very fine hairs and wax-secreting glands in the skin of the pinna and the meatus.
• The tympanic membrane is composed of connective tissues covered with skin outside and with mucus membrane inside.
• The middle ear contains three ossicles called malleus, incus and stapes which are attached to one another in a chain-like fashion.
• The malleus is attached to the tympanic membrane and the stapes is attached to the oval window of the cochlea.
• The ear ossicles increase the efficiency of transmission of sound waves to the inner ear.
• A Eustachian tube connects the middle ear cavity with the pharynx.
• The Eustachian tube helps in equalising the pressures on either side of the ear drum.
• The fluid-filled inner ear called labyrinth consists of two parts: the bony and the membranous labyrinths.
• The bony labyrinth is a series of channels.
• Inside these channels lies the membranous labyrinth, which is surrounded by a fluid called perilymph.
• The membranous labyrinth is filled with a fluid called endolymph.
• The coiled portion of the labyrinth is called cochlea.
• The membranes constituting cochlea, the reissner’s and basilar, divide the surrounding perilymph filled bony labyrinth into an upper scala vestibuli and a lower scala tympani.
• The space within cochlea called scala media is filled with endolymph. At the base of the cochlea, the scala vestibuli ends at the oval window, while the scala tympani terminates at the round window which opens to the middle ear.
• The organ of corti is a structure located on the basilar membrane, which contains hair cells that act as auditory receptors.
To be continued…
By
Dr. Modala Mallesh
Subject Expert
Palem, Nakrekal, Nalgonda
9989535675
