The ear itself is divided into two parts, namely the outer ear and the inner ear. In this inner ear has a function that is quite crucial, namely for hearing. This is because the inner ear is where sound waves are converted into electrical signals or nerve impulses. This allows the brain to hear and also understand sound.
Not only that, the inner ear also has a role in regulating balance. To understand it more deeply, let’s see the full explanation below.
Functions of the Inner Ear
There are two main functions possessed by the inner ear, namely helping to hear and also maintaining balance. Although each part of the inner ear is integrated with each other, the three work separately. The following is a complete explanation of the function of the inner ear, including:
1. Hearing Sounds
This part, which is similar to a snail’s shell, will work together with the outer and middle ear to help hear sounds. The cochlea which is filled with fluid and has a smaller and more sensitive structure is called the organ of Corti. Corti here acts like a microphone on the body, where this organ contains 4 rows of tiny hairs which will pick up vibrations from sound waves.
There are several steps that must be taken from the outer ear to the inner ear so that a person can hear sound, here are the explanations.
- The outer ear acts like a funnel, sending sound into the ear canal from the outside world.
- Sound waves will then travel down the ear canal to the eardrum in the middle ear.
- Then, sound waves make the eardrum vibrate and move the 3 small bones in the middle ear.
- Movement from the ear causes pressure waves that search the cochlea to move.
- Then, the movement of fluid in the inner ear causes the tiny hairs in the cochlea to bend and move.
- The hairs dance in the cochlea so that it converts the motion of sound waves into electrical signals.
- Electrical signals will be sent to the brain through the auditory nerve and then produce sound.
2. Keeping Balance
The part of the ear that regulates balance is the vestibule and also the semicircular canals. These semicircular canals are also filled with fluid and are also lined with fine hairs like those in the cochlea. The hair acts like a sensor that helps maintain body balance.
The channels sit perpendicular to each other to help measure every movement a person makes. When the head moves, the fluid in the semicircular canals will shift. The liquid then moves the tiny hairs in it when moved. The canal is connected by the saccule and utricle to sense movement.
The movement and balance sensors will then send electrical nerve messages to the brain. In turn, the brain will tell the body how to stay balanced. When we are on a rollercoaster or boat that moves up and down, the fluid in the inner ear may need to stop moving for a while. That is the reason why we may feel dizzy for a while after being in an imbalanced plane.
Inner Ear Anatomy
The inner ear is at the end of the ear tube. It is located in a small cavity like a slot in the skull on both sides of the head. There are three main parts of the inner ear, including:
This is the area of the inner ear that looks like a small, spiral-shaped snail shell.
2. Semicircular canals
This is a semicircular canal or what is called the Semicircular Canal which functions to feel balance and posture.
This is the part of the vestibule that is between the cochlea and the semicircular canal.
Outer Ear Anatomy
This outer ear structure is formed from the auricle or auricle and also the external auditory canal or ear canal. The auricle is formed by elastic cartilage which is attached to the oblique skin.
This section serves to capture sound and also localize sound. In addition, the auricle also forms a depression called the concha and the edges are called helices. The structure of the auricle itself consists of:
- triangular fossa,
- skaphoid fossa,
- and lobules.
The ear canal or ear canal is formed by cartilage and also the temporal bone. The size itself is about 4 cm from the outer ear to the tympanic membrane or what is commonly called the eardrum. The arch serves to prevent foreign objects from reaching our eardrums.
In addition to these structures, there are several sensory nerves in the outer ear, such as the auricular, facial, vagus, occipital nerves, and trigeminal nerves. The trigeminal, vagus, and facial nerves are part of the cranial nerves that directly connect to the brain.
Meanwhile, the auricular and occipital nerves are components of the spinal nerves. If there is a problem in the outer ear, ear problems can occur. For example, otitis externa or what is often called swimmer’s ear.
Middle Ear Anatomy
The function of the middle ear is to transmit sound that has been collected by the auricle to the inner ear. But before being sent, according to Kids Health, the part will convert sound waves into vibrations. The middle ear extends from the outer ear margin to the tympanic membrane.
In this section, there are three bones that are connected and will send sound waves to the inside of the ear. The three bones are called ossicles which consist of:
- Malleus (palu),
- incus (anvil), and
- stapes (stirrup).
Apart from these three bones, the anatomy of the middle ear consists of two main structures, namely the tympanic membrane and also the eustachian tube.
1. Tympanic membrane
The tympanic membrane, also known as the eardrum, is shaped like a flat cone and is also semi-transparent, which separates the outer ear from the middle ear. In this section attached to the ring of bone in the ear canal.
Then, in the center of the cone or hollow point it is called the umbo. Meanwhile, the part of the membrane that surrounds the umbo consists of two different parts, which are called the pars flaccida and also the pars tensa. There are three sensory nerves in the tympanic membrane, including:
- auriculotemporal nerve,
- intermedius nerve, and
- auricular branch of the vagus nerve.
2. Eustachian tube
The eustachian tube is the part of the ear that connects the middle ear to the upper esophagus and nose. Its function is to equalize pressure in the middle ear. Balanced pressure is needed for proper transfer of sound waves.
On the other hand, several medical conditions can occur if there is a problem in the middle ear. The following are some disorders that may occur in the ear that affect the middle ear.
- Otitis media.
- Burst ear drum.
How Can Someone Hear?
From the anatomy of the ear discussed above, we have learned about the structures that make up the ear, namely the outer, middle and inner ear. The three parts become sound channels from outside to enter and are translated by the brain. Reporting from Stanford Children’s Health , the hearing process will start from the outer ear which captures sounds in the form of vibrations or waves that are around us.
Then, the sound will be lowered into the ear canal, so that it will put pressure or a blow on the eardrum or tympanic membrane. When the eardrum vibrates, the vibrations are transmitted to the ossicles, so that the vibrations are amplified and sent to the inner ear.
Once the vibrations have reached the inner ear, the vibrations will be converted into electrical impulses and sent to the auditory nerve in the brain. Then the brain will translate these impulses as sound.
After knowing the anatomy of the ear, of course we understand that the ear does not only function as a hearing aid, but also functions to maintain balance. It allows us to walk, run, jump, and more without falling.
Causes of Damage and Disease in the Ears
Hearing ability is often not given proper attention. Many people are not aware that the process of hearing is actually a complicated process and can easily be lost due to an injury or disease in the ear. In fact, millions of people around the world suffer from some degree of deafness. Hearing loss usually occurs suddenly or gradually compared to those who are deaf from birth.
Sound itself is a vibration that arises from a source and then moves through the air. The process of changing sound so that it can be understood by the brain is called hearing. This hearing process occurs only when all components of the ear function normally. Damage to one or more components can cause a reduction to the loss of a person’s ability to hear.
One of the causes of hearing loss is ear injury resulting from loud noises, sudden blows, pressure, or the entry of foreign objects into the ear. It is important to remember that the components in the ear are very sensitive and also prone to damage.
The eardrum, also known as the tympanic membrane, is a thin tissue that sits between the outer and middle ear. Rupture or perforation of the eardrum is a common hearing loss that occurs due to too much noise, pressure, and the entry of foreign objects.
These disturbances can also result in ear infections that need to be treated immediately. If left alone, ear infections can spread to the inner ear and cause even more damage. The infection can even spread to the brain and damage nerves and other tissues, although this is rare. Other types of ear infections are vestibular neuritis and swimmer’s ear.
In addition, certain diseases can also damage the ear. Some of them are cholesteatoma, otosclerosis, Meniere’s disease, acoustic neuroma, and herpes zoster otitis. Otosclerosis usually attacks the middle ear and interferes with the function of the small bones. Where the disease can spread to the inner ear and result in a condition called permanent sensorineural hearing loss.
Meanwhile, cholesteatoma or a condition characterized by the growth of skin cells in the middle ear can destroy or interfere with the middle and inner ear. So it can cause hearing loss. If not treated immediately, this condition can result in severe ear damage.
Then, there is also Meniere’s disease which occurs when the fluid in the inner ear is not balanced. So that it causes ringing in the ears and excessive pressure. This condition must be treated immediately with appropriate treatment because it can cause total deafness.
In general conditions, otitis snakepox only attacks the facial nerve, but it is possible that the infection also attacks the nerves in the inner ear. Sufferers can experience hearing loss and also even hear foreign voices.
There is another ear disease called acoustic neuroma, which is a tumor that grows in the inner ear and brain. The growth of these tumors is usually very slow and benign, so the tumor is not cancerous.
However, if the tumor continues to grow, then the part of the ear around it will experience damage and various types of symptoms, ranging from vertigo and also loss of hearing. This tumor must be removed through surgery, but this action will only be carried out considering the patient’s age and also the size of the tumor in the patient’s ear.
Main Symptoms of Damage and Disease of the Ears
Besides having the main function as the sense of hearing, the ear also has a function as a means of balancing the body. Therefore, a person who has suffered from an injury or disease that can damage his ear, may experience dizziness or vertigo and nausea to a certain degree. Other symptoms may include deformed outer ear, fever, blocked ear canal, facial paralysis, and a foul-smelling ear discharge.
How to Overcome Ear Diseases
If you experience ear problems, then the best solution is to go to an ENT doctor. Because, this ENT doctor will help to treat various problems in the ear. Consult with an ENT specialist, be sure to start with a brief conversation about the symptoms of the disease, the severity, when the disease started, and also the drugs the patient has been taking to treat the disease.
After that, the doctor will examine the condition of the ear that is affected by the disease or is experiencing interference to find out any signs of infection. In addition, the eardrum will also be examined to find out if there is a hole in the eardrum.
After that, the patient’s hearing ability will be tested using a simple tuning fork. In some cases, the ENT doctor will refer the patient to an audiologist for more precise results.
After the ENT doctor knows the condition of the patient’s ear, the doctor will provide all available treatment options. The options are ear drops, oral medication, or surgery, depending on the condition of the ear and the severity.