Sound waves are vibrations that are transmitted with a certain frequency in all three media: liquid, solid and gaseous. For their perception and analysis by a person, there is an organ of hearing - the ear, which consists of outer, middle and inner parts, capable of receiving information and transmitting it to the brain for processing. This principle of operation in the human body is similar to that characteristic of the eyes. The structure and functions of visual and auditory analyzers are similar to each other, the difference is that hearing does not mix sound frequencies, it perceives them separately, rather, even separating different voices and sounds. In turn, the eyes connect light waves, while receiving different colors and shades.
Auditory analyzer, structure and functions
Photos of the main parts of the human ear you can see in this article. The ear is the main organ of hearing in humans, it receives sound and transmits it further to the brain. The structure and functions of the auditory analyzer are much wider than the capabilities of the ear alone,it is the coordinated work of the transmission of impulses from the eardrum to the stem and cortical regions of the brain responsible for processing the received data.
The organ responsible for the mechanical perception of sounds consists of three main sections. The structure and functions of the departments of the auditory analyzer are different from each other, but they perform one common job - the perception of sounds and their transmission to the brain for further analysis.
Outer ear, its features and anatomy
The first thing that encounters sound waves on the way to the perception of their semantic load is the outer ear. Its anatomy is quite simple: it is the auricle and the external auditory meatus, which is the link between it and the middle ear. The auricle itself consists of a 1 mm thick cartilage plate covered with perichondrium and skin, it is devoid of muscle tissue and cannot move.
The lower part of the shell is the earlobe, it is fatty tissue covered with skin and permeated with many nerve endings. Smoothly and funnel-shaped, the shell passes into the auditory meatus, bounded by a tragus in front and an antitragus in the back. In an adult, the passage is 2.5 cm long and 0.7-0.9 cm in diameter, it consists of an internal and membranous-cartilaginous sections. It is limited by the tympanic membrane, behind which the middle ear begins.
The membrane is an oval-shaped fibrous plate, on the surface of which such elements as the malleus, the posterior and anterior folds, the umbilicus and the short process can be distinguished. Structure andthe functions of the auditory analyzer, represented by such a part as the outer ear and the tympanic membrane, are responsible for capturing sounds, their primary processing and transmission further to the middle part.
The middle ear, its features and anatomy
The structure and functions of the departments of the auditory analyzer are radically different from each other, and if everyone is familiar with the anatomy of the outer part firsthand, then the study of information about the middle and inner ear should be given more attention. The middle ear consists of four interconnected air cavities and an anvil.
The main part that performs the main functions of the ear is the tympanic cavity, combined with the nasopharyngeal auditory tube, through this hole the entire system is ventilated. The cavity itself consists of three chambers, six walls and the auditory ossicle, which, in turn, is represented by the hammer, anvil and stirrup. The structure and functions of the auditory analyzer in the middle ear transform sound waves received from the outer part into mechanical vibrations, after which they transmit them to the fluid that fills the cavity of the inner part of the ear.
Inner ear, its features and anatomy
The inner ear is the most complex system of all three parts of the hearing aid. It looks like a labyrinth, which is located in the thickness of the temporal bone, and is a bone capsule and a membranous formation included in it, which completely repeats the structure of the bone labyrinth. Conventionally, the whole ear is divided into threemain parts:
- middle maze - vestibule;
- front maze - snail;
- posterior labyrinth - three semicircular canals.
The labyrinth completely repeats the structure of the bone part, and the cavity between these two systems is filled with perilymph, resembling plasma and cerebrospinal fluid in composition. In turn, the cavities in the membranous labyrinth itself are filled with endolymph, similar in composition to the intracellular fluid.
Auditory analyzer, structure of the ear, function of the receptors of the inner ear
Functionally, the work of the inner ear is divided into two main functions: the transmission of sound frequencies to the brain and the coordination of human movements. The main role in the transmission of sound to the parts of the brain is played by the cochlea, different parts of which perceive vibrations with different frequencies. All these vibrations are taken up by the basilar membrane, covered with hair cells with bundles of stereolicia at the top. It is these cells that convert vibrations into electrical impulses that go to the brain along the auditory nerve. Each hair of the membrane has a different size and receives sound only at a strictly defined frequency.
The principle of the vestibular apparatus
The structure and functions of the auditory analyzer are not limited to the perception and processing of sounds, it plays an important role in all human motor activity. For the work of the vestibular apparatus, on which the coordination of movements depends, the fluids that fill the part are responsible.inner ear. The main role here is played by the endolymph, it works on the principle of a gyroscope. The slightest tilt of the head sets it in motion, which, in turn, causes the otoliths to move, which irritate the hairs of the ciliated epithelium. With the help of complex neural connections, all this information is transmitted to the parts of the brain, then its work begins to coordinate and stabilize movements and balance.
The principle of coordinated work of all chambers of the ear and the brain, the transformation of sound vibrations into information
The structure and functions of the auditory analyzer, which can be briefly studied above, are aimed not only at capturing sounds of a certain frequency, but at converting them into information understandable to the human mind. All transformation work consists of the following main steps:
- Catching sounds and moving them through the ear canal, stimulating the eardrum to vibrate.
- Vibration of the three auditory ossicles of the inner ear caused by vibrations of the tympanic membrane.
- The movement of fluid in the inner ear and the fluctuation of the hair cells.
- Conversion of vibrations into electrical impulses for their further transmission through the auditory nerves.
- Promotion of impulses along the auditory nerve to brain regions and converting them into information.
Auditory cortex and information analysis
No matter how well-functioning and ideal the work of all parts of the ear would be, everything would be meaningless without the functions and work of the brain, which transforms all soundwaves into information and a guide to action. The first thing that meets the sound on its way is the auditory cortex, located in the upper temporal gyrus of the brain. Here are the neurons that are responsible for the perception and separation of all ranges of sound. If, due to any damage to the brain, such as a stroke, these departments are damaged, then a person may become hard of hearing or even lose hearing and the ability to perceive speech.
Age-related changes and features in the work of the auditory analyzer
With the increase in the age of a person, the work of all systems changes, the structure, functions and age-related features of the auditory analyzer are no exception. In people of age, hearing loss is often observed, which is considered to be physiological, that is, normal. This is not considered a disease, but only an age-related change called persbycusis, which does not need to be treated, but can only be corrected with the help of special hearing aids.
There are a number of reasons why hearing loss is possible in people who have reached a certain age threshold:
- Changes in the outer ear - thinning and flabbiness of the auricle, narrowing and curvature of the ear canal, loss of its ability to transmit sound waves.
- Thickening and clouding of the eardrum.
- Decreased mobility of the ossicular system of the inner ear, stiffness of their joints.
- Changes in the parts of the brain responsible for the processing and perception of sounds.
Besides the usual functional changes in a he althy person,problems can be aggravated by the complications and consequences of past otitis media, they can leave scars on the eardrum, which provoke problems in the future.
After medical scientists studied such an important organ as the auditory analyzer (structure and functions), deafness caused by age ceased to be a global problem. Designed to improve and optimize every part of the system, hearing aids help seniors live life to the fullest.
Hygiene and care of human hearing organs
To keep the ears he althy, they, like the whole body, need timely and accurate care. But, paradoxically, in half the cases, problems arise precisely because of excessive care, and not because of its lack. The main reason is the inept use of ear sticks or other means for mechanical cleaning of accumulated sulfur, touching the tympanic septum, scratching it and the possibility of accidental perforation. To avoid such injury, clean only the outside of the passageway and do not use sharp objects.
To save your hearing in the future, it's best to follow safety rules:
- Limited listening to music using headphones.
- Use special headphones and earplugs when working in noisy factories.
- Protection against water ingress into the ears while swimming in the pool and ponds.
- Prevention of otitis andcolds of the ears in the cold season.
Understanding how the hearing analyzer works, and following good hygiene and safety practices at home or at work will help you save your hearing and avoid hearing loss in the future.
