Your inner ear: one of the most important sense organs
Your inner ear consists of a labyrinth-like structure in the side of your skull and is filled with a liquid made from potassium and other substances. This fluid is called the endolymph. The bony labyrinth surrounds it the membranous labyrinth, which in turn floats in a sodium-rich liquid called perilymph. Deeper inside, your ear is connected to the tympanic cavity through two bone openings. These openings are called round and oval windows. The tympanic cavity is part of your middle ear.
Your inner ear is one of the most important of your sensory organs. This is where you will find the anatomical components of your sense of balance and hearing. So your inner ear is home to two different organs.
More about your inner ear
In order to be able to perceive an auditory impression, you have a cochlea in your inner ear, also called a cochlea. It consists of three different aisles that are separated from each other by membranes. The corridors are called
- Scala vestibuli ("vestibule")
- Scala media or ductus cochlearis ("snail duct")
- Scala tympani ("timpani staircase")
At the The tip of the snail (Helicotrema) merges with the scala vestibuli and the scala tympani. The basilar membrane forms the transition between the two aisles.
The Reissner membrane separates the cochlear duct from the scala vestibuli. It begins on the bony wall of the scala vestibuli and ends in the middle of the basilar membrane.
This is where the organ of Corti is located, on which the outer and inner hair cells are arranged. They make up the sensory cells of your inner ear. Its tips meet the tectorial membrane, a sluggish gelatinous mass. The incoming sound waves are converted and amplified by the outer and inner hair cells. When the vibrations hit the basilar membrane, the hair tips are mechanically stimulated to move. This converts the mechanical stimulus into an electrical nerve stimulus. This process is called stimulus transduction.
The vibrations then reach the brain as nerve impulses.
This is how you can hear - the function of your ears
Sounds are sound waves. When a sound wave hits your ears, your auricle forms a funnel through which the sound waves are transmitted to your eardrum. This is how your eardrum starts to vibrate. These vibrations are passed on to the oval window in your ear via the ossicles, consisting of a hammer, anvil and stirrup. Then the further transmission of the sound wave takes place. The electrical stimuli are generated via the hair cells. These electrical stimuli are passed on to your brain via the auditory nerve and processed.
The hair cells in your inner ear
Hair cells are special receptor cells whose tasks in the respective organs can be different. As secondary receptors, they convert mechanical stimuli into nerve stimuli.
Hair cells consist of a cell body and the hair-like structures at the top.
Your balance organ in the inner ear
Your sense of balance arises in the so-called vestibular apparatus. This apparatus is formed from three semicircular canals and two atrial sacs, the sacculus and the utriculus.
When your body is accelerated, the saccule and utriculus measure this acceleration. The three semicircular canals are located differently. They are distributed over the horizontal, the posterior and the anterior semicircular canals and are composed of an ampoule and arch.
The position of your body can be calculated by the brain based on the respective excitation of the three semicircular canals.
There is endolymph in the semicircular canals. All hair and sensory cells are in the ampoule. The tips of the hair cells protrude into the cupula.
For example, if you turn your head, this affects the sluggish endolymph, which flows backwards as it were due to this change in position. This distracts the cupula and stimulates your hair cells to move. The result is an electrical stimulus. Depending on which semicircular canal this stimulus arises in you, your brain then determines the specific position of your body.
Possible diseases of your inner ear
Your inner ear is a complex system. As such, it is very sensitive to disturbances, and many different complications can result from this:
If the sound pressure is increased, the hair cells can be damaged, which can lead to inner ear hearing loss. The hearing loss can often be compensated for with a hearing aid.
Inflammation can cause damage in both the middle and inner ear. If the most important structures are destroyed in the process, it leads to hearing loss or, in the worst case, deafness.
In addition, benign and malignant tumors can also cause hearing loss.