The structure of the ear includes the outer ear, the middle ear, and the inner ear, while the human sense of hearing is the ability to distinguish sounds from the environment. The ears are responsible for hearing. How exactly are they built?
In this article, Niketrainers.com.co will tell you:
Structure of the ear
The human ear is responsible for receiving external waves, which are later converted into mechanical vibrations and then into nerve impulses.
It is made of the ear:
- external,
- middle,
- internal.
The outer and middle ear belong exclusively to the hearing organ,while the inner ear contains receptors for both hearing and balance.
The outer ear
The outer earbegins with the auricle (auricula) on the lateral surface of the head in the form of a skin fold reinforced with cartilage elements. The turbinate passes into the external auditory canal (meatus acusticus externus).
Its lateral part has a cartilage skeleton (cartilago auricularis), while the medial part is made up of the temporal bone. This cable is made of leather.
Middle ear
The middle ear is separated from the outer ear by the tympanic membrane (tympani diaphragm). The largest part of the middle ear isthe tympanic cavity, which contains the ossicula auditis. Sound waves hitting the eardrum make it vibrate, which is transferred to the ossicles and this way they reach the inner ear where the appropriate receptors are located.
From the inner ear, information about the sound heard reaches the brain through the nerves. With age, senile deafness develops– hearing deterioration is caused by damage to the ear due to age.
The tympanic cavity narrows anteriorly, forming the Eustachian tube (tuba auditiva) that flows into the throat. The Eustachian tube is needed to maintain the pressure balance inside and outside the eardrum and to drain mucus and other secretions from the middle ear down the throat.
The inner ear
The inner earis a bone and membranous labyrinth located inside it.
The bone labyrinth is a complex system of interconnected lines:
- vestibule (vestibulum),
- snail (cochlea),
- three semicircular canals (canales semicirculares).
Inside there are elements of the membranous labyrinth, which are filled with a watery liquid, the so-called endothelium. The labyrinth contains sensory epithelia for both the hearing and balance organs. Moving the head moves the endothelium. This stimulates the sensory cells located within the labyrinth, which, through connection with the nervous system, send information to the brain about the movement made. It is similar with perceiving sounds.
Earlobe
The auricleis one of the organs that are very variable in terms of location, size and shape. The auricle grows slightly with age as it becomes flattened due to the loss of elasticity of the cartilage.
The auricle (auricula) is an irregular skin fold reinforced by elastic cartilage and covering the mouth of the external auditory canal. Only the lower, freely hanging segment of the pinna, called the lobe (lobulus auriculae), is devoid of cartilage. The lateral surface of the auricle is concave and richly modeled, while the medial surface is convex.
Free edge of the turbinate, the so-called the labrum(helix) is rounded, and its end, called the limb branch (crus helicis), divides the conch shell into two upper, shallower and smaller depressions called a shell boat (cymba conchae) and a larger lower one called cavum conchae. From the front, the shell is limited by a section (tragus) that protrudes slightly from the surface of the face and at the same time slightly covers the entrance to the external auditory canal. The dike (antihelix) forms an arcuate fold that forms the upper edge of the pinna shell. There is a longitudinal cavity called a scapha between the dam and the labrum. This shape of the auricle results from its function of collecting sounds.