The function of external auditory canal is as follows:
1, to prevent the eardrum from being infringed:
The narrow position of the external auditory canal is called isthmus, which can prevent foreign bodies from entering the external auditory canal and reduce local injuries, thus effectively protecting the tympanic membrane from foreign bodies and avoiding hearing loss.
2, easy to observe the situation in the ear:
If you feel uncomfortable in your ears in your daily life, or your eardrum hurts. Lifting the auricle upward when examining the eardrum can straighten the external auditory canal, which is convenient for observing the situation in the ear and carrying out targeted treatment according to the situation;
3. Sound collection and pressurization:
The external auditory canal is a curved pipe extending from the external auditory canal to the tympanic membrane, which can effectively transmit the sound waves collected by the auricle to the tympanic membrane, and can play the role of sound collection and pressurization, so that the sound can be heard more clearly and accurately;
4, sound source location:
Because the external auditory canal has a good sound collection function, when there is sound coming from the outside, the external auditory canal can not only transmit sound waves to the eardrum, but also to the inner ear through the middle ear, so as to achieve the best hearing function of the ear and also have the function of sound source localization.
Extended data:
The external auditory canal is a curved pipe extending from the external auditory canal deep in the external auditory canal to the inner side of the tympanic membrane, which can transmit the sound waves collected by the auricle to the tympanic membrane in the direction of inward upward, then inward upward and then inward downward; Adults are about 2.5 ~ 3.5 cm long. Because the tympanic membrane is inclined, the anterior lower wall (3. 1cm) of the external auditory canal is longer than the posterior upper wall (2.5cm).
The lateral13 of the external auditory canal is a cartilaginous external auditory canal based on the cartilage of the external auditory canal, and the medial 2/3 is a bony external auditory canal based on bones. The connection between them is very narrow; The stenosis is about 2cm away from the external auditory canal, and the narrowest part of the external auditory canal is called isthmus, which can prevent foreign bodies from entering the external auditory canal and invading the tympanic membrane.
The baby's bony external auditory canal is underdeveloped, and the bottom and top of the cartilaginous external auditory canal are cracked, facing inward and downward. When checking the eardrum, the auricle should be pulled down and the tragus should be pulled forward. The skin of the external auditory canal is thin and closely connected with the perichondrium and periosteum. Cartilaginous external auditory canal skin is rich in hair follicles, sebaceous glands and cerumen glands, which is one of the most common parts of boils.