The structure of the ear is one that can receive sound waves and convert them into vibrations

Hello! b. Tympanic membrane.

External sounds are collected by the ear and transmitted from the external ear canal to the eardrum, causing the eardrum to vibrate. The frequency at which the eardrum vibrates and the frequency at which sound waves vibrate is exactly the same. The louder the sound, the greater the amplitude of the vibration of the eardrum.

Although the tympanic membrane is thin, it has three layers of anatomy (tension): The epithelial layer is continuous with the external auditory canal**. The middle layer is composed of radial and annular cilia, so it has some elasticity and tension.

It is a fibrous layer (radial on the outside and a wheel on the inside). There is a small part above the tympanic membrane, which does not have an intermediate fibrous layer, which is relatively thin and flaccid, which is called the flaccid part, while the part of the tympanic membrane with a fibrous layer is called the tension part. The malleus stem is attached to the middle of the fibrous layer.

The inner layer is the mucosal layer, which continues with the tympanic mucosa. After tympanic membrane perforation, the outer epithelial layer and the inner mucosal layer are able to regenerate, but the middle layer has no regeneration ability. The flaccid tympanic membrane lacks a median layer.

The malleus stem is embedded in the tympanic membrane from top to bottom, and is attached to the tympanic membrane, so that the tympanic membrane is pulled inward to make it funnel-shaped, much like the speaker of the radio, and its ** depression is called the tympanic umbilicus, and there is a gray-white dot-like small protrusion from the umbilicus upwards to the upper edge of the tension part, called the hammer convexity, that is, the malleus brevis protrusion tops the tympanic membrane site, which is clinically called the malleus brevity. Hammer convexity is caused by the short process of the malleus bone pushing up the eardrum. On the surface of the tympanic membrane, there is a white stripe from the front to the back between the umbilicus and the hammer convex, which is formed by the malleus stem moving in the eardrum, which is called the hammer pattern.

The end of the warp pattern is just at the ** part of the eardrum, called the umbilicus. In front of the umbilicus, the lower part of the umbilicus descends from the umbilicus to the edge of the tympanic membrane, a triangular reflective area, called the light cone. The light cone is caused by the reflection of light projected onto the eardrum, and the shape and position of the light cone often change when the shape of the eardrum changes.

There is a fold before the hammer convex and on the side, the former is called the anterior fold, and the latter is called the posterior fold. Above this fold, the tympanic membrane is more relaxed, called the flaccid part, which is directly attached to the scale of the temporal bone. Below it is the tension part, which is embedded in the drum groove of the drum bone by the drum ring.

For the purpose of clinical recording, the tympanic membrane is often divided into four quadrants, i.e., an imaginary straight line along the malleus stem, and a straight line perpendicular to it through the tympanic umbilicus, which can divide the tympanic membrane into four quadrant areas: anterior superior, anterior inferior, posterior superior and posterior.

b The tympanic membrane is a thin film that tends to respond to small pressure changes (sound waves) and form vibrations.

The ear is our (auditory organ) and it is the eardrum that converts sound waves into vibrations.

The eardrum is an oval, pale gray, translucent membrane. It is located at the bottom of the external auditory canal and serves as the boundary between the outer and middle ears. The majority of the tympanic membrane is attached to the tympanic groove of the temporal tympanic, and a small part of the upper part is attached to the scales.

The part attached to the drum groove is more solid, called the tension part; The part attached to the scales is thin and loose, and is called the relaxation part. The tympanic membrane is concave inward, and the tip of the depression is called the tympanic umbilicus.

Structures that increase sound pressure during the passage of sound waves to the inner ear include the ossicular chain, the external auditory canal, and the tympanic membrane.

Sound is transmitted to the inner ear through air conduction and skull conduction. Generally based on air conduction, sound produces sound waves, collected by the auricle, reaches the tympanic membrane through the external auditory canal, and is transmitted from the vestibular window to the inner ear epilymph through the lever of the ossicular chain, causing the basement membrane to vibrate, generating nerve impulses, and passing through the auditory nerve to the auditory center to produce hearing.

Physiology of the ear

The ear can be divided into three parts: the outer ear, the middle ear, and the inner ear, which connect the auditory nerve to the brain and constitute the human auditory system.

The structure of the ear passes from the pinna of the outer ear into the external auditory canal, followed by the middle eardrum (tympanic membrane); There are three ossicles in the middle ear cavity, namely the hammer bone, the incus and the stapes. The stapes touch the foramen ovale of the inner ear, from which sound travels to the inner ear. The structure of the inner ear can be divided into two main parts.

The cochlear part is responsible for hearing and is integrated into the cochlear nerve, the vestibular semicircular canal part is responsible for balance, and the semicircular canal part is integrated into the vestibular nerve, which in turn combines to form the vestibular nerve of the cochlea, which is the eighth cranial nerve, which then enters the auditory nucleus of the brainstem and then reaches the auditory center of the brain. The main area of the auditory center is in the temporal lobe of the brain. Therefore, the ear is only used to transmit sound, and ultimately the brain still has to listen to sound.

Hello landlord, information collected on the Internet:

The hair cells of the Corti organ transform fluid waves into neural signals.

Afferent neurons are innervated by key-shaped intrinsic hair cells, and at synapses, the neurotransmitter glutamate transmits signals from hair cells to the dendritic protrusions of major auditory neurons.

There are a small number of intrinsic hair cells in the cochlea farther than the input nerve fibers. The dendritic prominences of the nervous system belong to the neuronal auditory nerve, which in turn joins the vestibular nerve to form the vestibulocochlear nerve, or cranial nerve viii.

Outgoing projections from the brain to the cochlea also play a role in the perception of sound. Efferent synapses occur in the outer hair cells and in the input (toward the brain) dendrites below the inner hair cells.

Auditory system.

This sound information, which is now encoded again, moves under the vestibulocochlear nerve through the part of the brainstem (for example, Spoon nucleus and Inferior colliculus), which are further processed at each station. The information eventually reaches the thalamus, and from there it is transmitted to the epidermis. In the human brain the main auditory cortex is located in the temporal lobe.

Lymph and hair cells inside the vortex tube.

Sounds of different pitches have different rows of waves in the lymphatic fluid, and the sound can be distinguished by the excitation of hair cells at different positions through the different positions of the waves.

The cilia of hair cells have gated ion channels that are sensitive to tension and shear forces, and fluctuations in lymph cause the cilia to bend, thus opening the channels to form excitation.

Check the answer analysis [Correct Answer].

1.Air conduction: Air conduction is the main pathway for the acoustic celery wave to enter the inner ear. In addition, vibrations of the tympanic membrane can cause air inside the tympanic to vibrate, which then passes through the round window membrane to the inner ear.

2 Bone conduction: Bone conduction has low sensitivity and has little effect on normal hearing formation, but when the tympanic membrane or middle ear lesion causes significant impairment of air conduction, bone conduction is not affected, and even relatively strengthened.

It is the cochlea that converts sound waves into vibrations.