Every five human senses has a very important task, including the ear. Not surprisingly, ear material is widely studied in Biology. This time, we review the notions of the ear, parts of the ear, ear function and abnormalities in the ear. By knowing about this material, we will be able to get to know the intricacies of the ear better, while understanding how the ear performs its role as one of the five senses.
Definition of Ear
The senses are the organs of the body which have the function of knowing the external circumstances. This sense organ is called the five senses, one of which is the ear. The ear has a function to observe sounds or sounds.
Sound is produced when an object vibrates, as a result the surrounding air also vibrates and produces sound waves. The ear can distinguish between strength, speed, and direction of vibration. The human ear can hear sounds with a frequency of around 20 Hz – 20,000 Hz. The nerve that serves the sense of hearing is the eighth cranial nerve or auditory nerve.
Part – Part Ear
The ear is the sense of hearing which consists of the outer ear, middle ear, and inner ear. The outer ear consists of the auricle, ear canal, auditory canal, oil glands, and the drum membrane or tympanic membrane.
In addition, the outer ear consists of auricles or pinna, which in lowly large animals can move and help collect sound waves.
Then, the externa auditory meatus protrudes inwardly away from the pinna, and delivers sound vibrations to the tympanic membrane.
This burrow is about two and a half centimeters long and the outer third is cartilage while two-thirds inside is bone. Raglan cartilage is not straight and moves towards the top and back.
This can be straightened through the ear lift up and back. This is generally done if we want to spray the ears. The spray liquid must be directed to the posterior wall and upper wall of the ear canal. After being sprayed and examined, the remaining fluid can be flushed out by the patient.
This Auricle is irregular in shape and consists of cartilage and fibrous tissue, except at the lower end of the ear lobe consisting of fat.
There are three muscle groups in the front, top and back of the ear. However, humans are only able to move their ears so little that they are almost invisible.
The outer ear has a function to capture stimuli in the form of sound or sound. The eardrum may rupture as a result of excessive air pressure caused by an explosion, lightning, or the like.
On the walls of the external ear canal, serumen oil, and fine hairs have a function to filter out foreign body disorders. If there is interference at the sound wave receptors or in the nervous system, then hearing will experience interference can even cause deafness.
Meanwhile, the middle ear consists of the eardrum, three listening bones including hammer, foundation, and stirrup, and the eustachian tubes. Middle ear in the form of ear cavity which contains air.
The middle ear or timpani cavity is a small room with air. The cavity is located on the inside of the timpani membrane or ear drum, which separates the cavity from the meatus auditorius externa.
The cavity is narrow and has bone and membrane walls. While the back part connects with the mastoid antrum in the mastoid process in the temporal bone, through a gap called aditus.
The eustachian tube moves forward from the middle ear cavity to the nasopharynx, then opens. Thus, air pressure on both sides of the eardrum can be regulated equally through the auditory meatus externa, and through the eustachian tubes or tympanic pharynx.
The eustakhius tubes are closed when normal and open every time we swallow. As a result, the air pressure in the timpani space is maintained to keep the air pressure in the atmosphere. Thus, injury or neglect due to air pressure imbalance, can be avoided.
This contact with nasopharynx allows infection of the nose or throat to spread into the middle ear cavity.
The hearing bones are three small bones arranged in the middle ear cavity like chains that connect from the tympanic membrane to the inner ear cavity.
The outer bone is the malleus, shaped like a hammer with a handle attached to the tympanic membrane, while its head protrudes into the tympanic space.
The bone in the middle is the incus or base, the outer side is joined to the malleus, while the inner side is joined to the side by a small bone called stapes.
Stapes or spines, which are associated with the incisors with smaller ends, while the base is longitudinally related to the membrane covering the vestibuli fenestra or window. These bones have the function of transmitting sound vibrations from the ear drum to the inner ear cavity.
The mastoid process is part of the temporal bone behind the ear, while the air space at the top is the mastoid antrum which is connected to the middle ear cavity.
Infection can spread from the middle ear cavity to the mastoid antrum, and thus cause mastoiditis.
The three hearing bones, the hammer, the base and the stirrup connecting the outer ear and the inner ear. The eustachian tubes connect the ear cavity with the oral cavity. This channel has a function to keep the air pressure outside and the air pressure inside the ear equal.
The inner ear cavity is in the temporalis bone ospetrosum. The inner ear cavity consists of various cavities that resemble the channels in the temporal bone.
The cavities are called bone labyrinths and are lined with membranes to form membranous labyrinths. These membranous ducts contain fluid and the nerve endings of the hearing and balance
The labyrinth of bones consists of three parts. Vestibula is the middle part, and where the other parts are joined together. Semicircular canal continued with vestibule.
There are three types of channels – the superior, posterior and lateral channels. The lateral channels are horizontal, while the three are perpendicular to each other.
At one end of each channel there is a thickness called the ampula. Ampula is a fluid movement that stimulates the final nerve endings in this ampule that make us aware of our position.
The inner ear is divided into body equilibrium, three-and-a-half channels, a window, a circular window, and a snail or cochlea house.
The cochlea is a spiral tube that wraps itself like a cochlea. The windings encircle a cone-shaped axis that has a central part of the bone, called a mochulus. In each winding, there is a membrane that contains the ends of the auditory nerve.
The cochlea contains lymph fluid and sensory cells that are connected to the brain by the nerves of the listener. Fluid in the membranous labyrinth is called the endolymph while fluid that is outside the membranous labyrinth and in the labyrinth of bones is called perilinfe.
There are two windows in this circular chamber, the vestibuli fenestra and the cochlea fenestra. Vestibuli fenestra or the so-called ovalis phenestra because it is elliptical and covered by bone stapes.
The cochlea phenestra or the so-called rotunda fenestra, because it is round and is closed by a membrane.
Both are facing the inner ear. These windows in the bone marrow are intended for the inner vibration to be removed from the middle ear cavity, to be carried through the periphery. Perilimfe is a practical liquid that cannot be compacted.
The vibrations in the periphery are directed toward the endothelium, and thus stimulate the end-points of the auditory nerve.
The auditory nerve or auditory nerve consists of two parts, one of which is the collection of sensibility from the vestibular portion of the inner ear cavity that has a relationship to balance.
These nerve fibers move towards the vestibular nucleus which is at the meeting point between the pons and medulla oblongata, then move towards the cerebellum.
The part of the kokhlearis in the auditory nerve is the actual listening nerve. The nerve fibers are first emitted in a special nucleus that is just behind the thalamus, then from the same it is re-emitted towards the final receiving center in the cortex of the brain in the abwah part of the temporal lobe.
Injury to the kokhlearis nerve will result in nerve deafness, while injury to the vestibular nerve will result in vertigo, ataxia, and nystagmus.
The inner ear is the part that has the function to receive stimulation. What is the function of the parts of the listener’s senses?
also see: Understanding Microscopes, Functions and Parts
Function Part – Listening Sense
This section will explain the function of the parts of the listener’s senses, which are explained as follows
The auricle, ear hole and auditory canal have the function to capture and collect sound waves.
The ear drum has the function of receiving a sound stimulus and passing the sound deeper.
Three hearing aids include hammers, sockets, and handles that have the function of amplifying vibrations and passing vibrations to the cochlea or snail house.
Pillow windows, circular windows, three-and-a-half channels and a cochlear or snail house have the function of changing impulses and passing them to the brain. Three-and-a-half channels also have the function of maintaining body balance.
Eustachian tube has a function to connect the oral cavity with the outer ear. What is the mechanism of human hearing?
Human Hearing Mechanism
The sound or sound causes sound waves to propagate in the air. The earlobe captures, holds, and transmits sound waves toward the eardrum. Then, the eardrums vibrate.
The vibrations in the eardrum will be transmitted through the hearing bones to the channels in the inner ear.
With the vibrations of these channels, the lymph fluid in the cochlea also vibrates, causing stimulation of sensory cells. These stimuli are then conveyed to the brain by the nerves of the listener.
Finally humans can hear the sound or sound. Humans can hear sounds or sounds with a frequency of 20-20,000 Hz, while bats can catch vibrations up to 100,000 Hz and dogs can hear up to 30,000 Hz.
After understanding about the mechanism of human hearing, what are the next abnormalities in the ear?
Abnormalities in the Ear
The kinds of abnormalities in the ear are as follows
- Deafness is the disruption of sound flow to the cochlea and this may be caused by dirt in the ear or inflammation in the middle ear. Deafness is divided into two namely nerve deafness and conductive deafness. Nerve deafness is deafness caused by hearing loss and damage to the auditory part of the brain. Conductive deafness is a disorder caused by factors, namely tearing of the eardrum, disturbance of the ear canal or canal, calcification of the connection of the auditory bone, stiffness of the connection of the stirrup bone with the ovarian fenestra, and blockage by cerumen oil.
- Inflammation of the middle ear, caused by bacteria or viruses.
- Disorders of the labyrinth, such as nausea, vomiting, ringing, even deafness.
Such an explanation of the parts of the ear to the abnormalities experienced in the ear. Hopefully this article is useful and happy learning.