The sense organ responsible for hearing is our ear, also called heard. In order to better understand its function, it is customary to divide it into three parts: outer ear, middle ear It is inner ear.
ear structure
The external ear is our ear, which, with the auditory pavilioncaptures the sound passing through the ear canal until you reach the eardrum, where the middle ear begins. In our external ear, there are sebaceous glands responsible for the secretion of wax. The function of wax is to protect our middle and inner ears from microorganisms and dust that can cause infections, damaging our hearing.
The middle ear begins at the eardrum, and when sound reaches this structure, it immediately transfers this stimulus to the ossicles that are part of it: the hammerThe anvil and the stirrup. Also in the middle ear is a flexible canal called the Eustachian tube, which allows communication with the throat. It is in this channel that regulation of pressure in our ear occurs. If we go up or down a mountain range, we can perceive pressure inside our ear due to the difference in atmospheric pressure inside the ear and outside it. If we yawn or swallow saliva, the tubes open, equaling the pressure, and improving the feeling of pressure in our ear.
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How do we perceive the sound stimulus?
When the sound reaches the eardrum, it transfers this stimulus to the middle ear ossicles (hammer, anvil and stapes), which transmit these vibrations to the inner ear. The inner ear is located on the temporal bone in our skull. Vibrations arriving from the middle ear ossicles pass through a membrane, the oval windowuntil they reach cochlea, a fluid-filled organ that resembles a snail’s shell. Inside the cochlea, in addition to the liquid, there is a membrane full of sensory cells cilia that are grouped in the organ of corti. Over the organ of Corti is the tectorial membrane, which rests on the cilia of the sensory cells. By stimulating the eyelashes, a nerve impulse which is transmitted to auditory nerve and consequently to the center of hearing in the cerebral cortex.
Paula Louredo
Graduated in Biology