Ear structure diagram – ear structure diagram and function [with map]

Ear structure-Ear structure diagram and function[With map]

The eyes are the window of the soul, the ear is the portal of the brain. Nowadays, many friends have poor hearing. Many reasons can cause hearing loss in the ear. Although the hearing aid can help improve the hearing level, at the same time, we must properly grasp some ear hearing health knowledge. Huasheng will share with you the internal structure of the ear!

What is the structure and function of the normal human ear? The ear is the auditory organ of the human body. It consists of the outer ear, the middle ear and the inner ear.

External ear: The outer ear consists of the auricle and the external auditory canal. The auricle is located on both sides of the skull, shaped like a shell, with front and rear sides, uneven front and convex, auricle with cartilage as a support, covering the skin, with good deformability, the auricle mainly plays the role of collecting sound. Ear structure

The external auditory canal connects the auricle and the middle ear, from the outside to the inside.”S”Curved, outsideOctober 1For the cartilage, insideOctober 2For the bones, in the adult length2.5-3.5 cmThe length of the external auditory canal of children varies with age. External auditory canal3000 HzThe left and right frequency sounds have resonance and can improve the sound of these frequencies.10 dBabout. Because the external auditory canal is curved, and the external auditory canal of the child is not fully developed, the auricle must be lifted back when looking at the adult tympanic membrane. When observing the tympanic membrane of the child, the auricle should be pulled backwards and downwards.

Middle ear: Located between the outer ear and the inner ear, it consists of four parts: the tympanic cavity, the eustachian tube, the sinus sinus and the mastoid.

Tympanic: A bone cavity containing three small bones. The tympanic chamber can be viewed as a hexahedron with the following features:

The outer wall of the tympanic cavity is mainly composed of a tympanic membrane, which is a very thin membranous tissue that can be vibrated by the sound and transmitted to the ossicular chain (hammer, anvil and tibia) connected to it. The latter is connected to the inner ear through the vestibular window on the inner wall of the middle ear. The energy of the sound is transmitted to the inner ear in this way, stimulating the hair cells to produce bioelectricity and then spread to the auditory center. . There is a protruding structure in the middle of the inner wall called the drumstick, and there is a vestibular window (oval window) on the back of the drum. It is the passage of the ossicular chain to the inner ear, and there is a round window at the back of the skeleton. The window), closed by a layer of film, plays a very important role in the completion of the transmission of acoustic energy in the inner ear. The front wall of the tympanic cavity has an opening called the eustachian tube, which is open to the eustachian tube. The eustachian tube connects the tympanic cavity and the pharynx.3.5-4.0cmIt has the function of regulating the pressure of the middle ear and the outside world. If there is stenosis or obstruction, it will lead to a decrease in conductive hearing. Children’s eustachian tube is short, straight, wide, and more horizontal. The infection of the pharynx is more likely to spread to the middle ear, so children are prone to otitis media.

Because the effective vibration area of ​​the tympanic membrane is larger than the area of ​​the tibia floor17In addition, the ossicular chain has the function of a lever, and its long arm is located at one end of the tympanic membrane, so that when the sound is transmitted from the tympanic membrane to the inner ear lymph, the energy is increased.30dB, to make up for the loss of sound when the air is introduced into the liquid.

In summary, it can be seen that the middle ear plays a role mainly in conducting and expanding the sound.

Inner ear: The structure is very complicated, consisting of three parts: the vestibule, the semicircular canal and the cochlea. The first two parts are responsible for balancing the feelings, while the latter are related to hearing.

The shape of the cochlea is like a shell of a snail. There is a bone axis in the middle. The spiral bone tube spirals from the bottom to the top of the worm shaft for a total of two and a half weeks or two and a half weeks. Mid-week and top week, full length30mm. The hollow bony spiral tube is divided into three lumens by the bone tissue and the membrane structure, which are called vestibular, intermediate (coil) and tympanic.

The vestibular step is connected to the ossicular chain through the vestibular window; the tympanic membrane is adjacent to the tympanic membrane by a round window membrane; the vestibular and tympanic steps are filled with the perilymph. The middle stage is a blind tube with a membranous structure, and there is an internal lymphatic fluid inside, which has important structures related to the perceived sound.–The auger, which we often say, is located in this part.

When the sound reaches the inner ear, it first causes the fluctuation of the perilymph, which in turn affects the middle and the endolymph, which stimulates the hair cells to produce bioelectricity. The latter conducts along the auditory and auditory conduction pathways to the auditory center, and the auditory center receives the The signals are analyzed and integrated to produce“listen”a feeling of.