The ear, in addition to being an auditory organ, is a complex system that allows humans to listen and walk. It is made up of three main parts: the outer ear, the middle ear, and the inner ear. Thus, all parts have different characteristics that facilitate both hearing and balance.
How hearing works
The outer ear (called the pinna) is the part of cartilage and skin that we have on the outside of the head. It works like a megaphone, as the sound waves that are collected through the outer ear travel to the ear canal. For its part, the auditory canal is the part of the ear hole that can be easily seen when we look at an ear closely.
The sound waves get through the ear canal and reach the eardrum (tympanic membrane). And, just like when a drum is struck, the connective tissue membrane vibrates when sound waves hit it. In this way, the vibrations travel through the eardrum and enter the middle ear, also known as the tympanic cavity. The tympanic cavity is lined with mucosa, air, and has auditory bones (tiny bones called the hammer, anvil, and stapes).
According to the National Library of Medicine, as the bones vibrate, the stirrup pushes in and out on a membrane called the oval window. Thus, they manage to transmit the vibrations to the inner ear and the cochlea, a spiral-shaped structure (similar to a snail) filled with fluid that contains the organ of Corti (that is, the hearing receptor organ). The cells of this organ, in turn, translate the vibrations into electrical impulses that the sensory nerves send to the brain.
How Ears Help Balance
The Eustachian tube (also known as the pharyngotympanic tube) helps equalize the pressure of the air in the middle ear with the pressure of the air in the atmosphere. This process helps people maintain balance.
Likewise, the vestibular system, present in the inner ear, also plays an important role, since it contains receptors that regulate the sensation of balance. In addition, the inner ear is connected to the vestibulocochlear nerve, which is responsible for transporting all the information related to sound or balance to the brain.
