Eardrum

Eardrum - webbed education, which is the boundary between the outer and middle ear. The eardrum is fixed in the bone groove of the temporal bone, except for the upper part. Eardrum consists of tight and loose parts. Stretched part of the eardrum has 3 layers: the outer epidermis, which is the direct continuation of the skin of the ear canal, internal mucous membrane lining the tympanic cavity and medium - fibrous. The middle layer is missing in the loose part of the eardrum, which explains the smoothness.
Eardrum with a chain auditory ossicles is of great importance in the transmission of the sound pressure, and more functional importance are its lower parts. Eardrum protects the middle ear from being hit by debris and micro-organisms.
Damage to the eardrum can occur as a direct result of exposure to damaging of the object (for example, the metal splinter, tools for gross manipulation), and under the influence of the air waves (see Barotrauma). In some cases the gap eardrum is one of the symptoms of a fracture of the skull base.
First aid in case of rupture of the eardrum is the introduction of a lump sterile cotton wool in the ear canal and the dressing. With the preventive purpose (to avoid the development of inflammation of the middle ear) prescribe antibiotics and sulfa drugs. The patient is forbidden to blow your nose. Contraindicated cleaning the ear from the blood and even mud, and an introduction to the ear canal medicinal substances. After rendering first aid to a patient is sent to the otolaryngologist.
Inflammation of the ear drum - meningiti very rarely are the primary. Often they are accompanied by inflammation of the external ear canal or middle ear can develop as a result of chemical and thermal effects. Symptoms and treatment - see Otitis.
Operations on the eardrum - see Paracentesis, Tympanoplasty.

eardrum

Eardrum (membrana tympani, myrinx) - thin, stretched tight across the membrane, demarcates the ear canal from the tympanic cavity. Develops eardrum from mesoderm tissue on the border between the external auditory canal, middle ear cavity.
Bpts his thickened edge (anulus fibrocartilaginous) firmly fixed in the bone ring temporal bone (sulcus tympanicus); in the top division ring is missing, and bpts is attached to a small bone cutting [incisura tympanica (Rivini) (BNA)]. The main part bpts, encased in bone ring, called tense (pars tensa), the other, a much smaller proportion - sagging (pars flaccida), or shrapnell membrane (membrana Shrapnelli). Both parts bpts significantly different from one another morphologically and functionally.
The border between these parts are front and rear hammer folds (plicae malleolares ant. et post.), which begin outside from the ends incisura tympanica and finish at short process hammer, attached to the inner surface bpts Through normal bpts you can see a few short acting process and further-reaching down and backwards pinkish the handle of the hammer (prominentia malleolaris), also welded to the inner surface bpts (see Otoscopy).
In connection with that that the handle of a little hammer approximately 30 degrees rejected inside, conical involved inside and bpts; the largest (up to 2 mm) retraction bpts matches the end of the arm and called the navel of the eardrum (umbo membranae tympani).
The eardrum is wrong oval and is inclined position relative to the axis of the external ear canal, forming the upper wall of the corner of 40-50°, bottom - 30 degrees, with the front - 27 degrees and with the back - 140 degrees.
In newborns bpts is more than horizontally.
Adult size stretched pieces bpts - about H mm, sagging part - 2X3 mm; thickness bpts - 0,1 mm bpts has a grayish-pearly color with a small glimmer in artificial light becomes brighter in the light cone. The latter is obtained in predaniyam Department bpts and rests on top of the umbilical region (printing. table, Fig. 1).
Eardrum consists of three layers: the outer (stratum cutaneum), which is a direct extension of the skin of the ear, but here strongly thinned, internal (stratum mucosum), which is a continuation of the mucous membrane of the tympanic cavity, and medium - fibrous layer (stratum fibrosuin), in which there are external fibre located rudiano (stratum radiatum), and internal located circular (stratum circulare). In the field shrapnell fibrous membrane layer is missing.
Blood vessels bpts presented in two Anastasiya interconnected networks: outer-related vessels ear, and inner-related vessels tympanic cavity. The next regional lymph nodes are on the sternoclavicular-liners muscle. Nerves bpts branch is similar to blood vessels in the skin layer twigs from p. auriculotemporal in the interior - from drum plexus tympanicus).
The main function of bpts - sound transmission and transformation (gain). Transformation of a sound bpts is due to its conical shape. Fluctuation amplitude bpts between the navel and the periphery is significantly more than in the umbilicus; consequently, the umbilical region and chain auditory ossicles fluctuate with more force than the original sound wave. Transformation of a sound is also thanks to the relatively large surface bpts, which is 20-25 times higher than the surface of the foot plates stirrup. Thus, sound with a large surface bpts is passed through the chain of auditory ossicles and as it concentrates on a small square foot plates stirrup, which also helps to increase the strength of sound vibrations. In the absence of bpts and auditory ossicles hearing loss reaches 20-30 dB. The eardrum is a very durable membrane and withstands pressure of up to 100 mm RT. Art.
Pathological changes of the eardrum often result from diseases of the tympanic cavity (see Otitis media) or ear canal. Much less frequent are distinct diseases bpts - damage and inflammation. In violation of ventilation tympanic cavity (due to a pathological state of the auditory tube) is indrawing bpts, it loses its luster and its contours are identified more sharply (printing. table, Fig. 2). With adhesive otitis media and tympanosclerosis bpts thickens, in the thick of it appear lime deposits (petrifikatov) or fibrosis. Acute inflammation of the middle ear initially cause the light injection vessels bpts (printing. table, Fig. 3); then redness applies to all bpts, she infiltered, sometimes stuck out exudate (printing. table, Fig. 4). Chronic suppurative otitis media in bpts always there is a persistent perforation. There are perforation of the Central, regional (printing. table, Fig. 5-8) and perforation in shrapnell membrane. Perforation of the last two localizations characteristic of severe forms of chronic otitis.

eardrum
Fig. 1. Normal eardrum. Fig. 2. Indrawing of the eardrum. Fig. 3. Eardrum in the initial stage of acute inflammation of the middle ear. Fig. 4. Eardrum, protruding inflammatory exudate. Fig. 5. Central perforation. Fig. 6. Central perforation with granulations. Fig. 7. Central perforation with cholesteatoma. Fig. 8. Regional perforation.

Damage to the eardrum divided into direct and indirect. When trauma bpts observed her tears and often complete destruction. At the time of the break bpts see the following symptoms: a sharp pain, ear noise, sometimes unconscious. Decreased hearing. In the future, if you don't join infection, small breaks bpts quickly healed. Treatment of injuries bpts is to protect the middle ear from infection. Burns eardrum chemicals, hot liquid or vapour is celebrated her reddening and blistering, while deep burns - necrosis and destruction. Severe pain caused by burns, calm analgesics, bubbles opened. Damage bpts when a sudden change in barometric pressure - see Barotrauma.
Primary isolated inflammation of the ear drum (Moringa) can be acute or chronic. Acute miringa (myringitis acuta) is a rare disease, usually caused by infection. Occurs in childhood. Characterized by redness, swelling bpts and education under the epidermis bubbles with serous fluid (myringitis bullosa); in more severe forms occur small abscesses. Patients are suffering moderate pain, noise, feeling of fullness in the ear and heaviness in the head. The ear is reduced slightly. The temperature remains normal. The disease usually ends favorably: after 3-4 days of small abscesses dissolve or opened out, after about 7-8 days bpts normalized. Treatment: analgesic, antiseptic, opening an abscess.
Chronic miringa (myringitis chronica) usually develops after acute eringeti or transferred outside or otitis media. Expressed in thickening, hyperemia and looseness of the eardrum. Outside bpts covered with yellowish-white secret that belies its contours. Sometimes there fungal overlay (requires research). In some cases, on bpts grow small granulation (myringitis granulosa). Patients complain of severe itching and a feeling of pressure in the ear. The ear is reduced slightly. Chronic miringa difficult to treat and easy recurs. Treatment: removal of purulent secretion by ear wash with a weak solution of resorcinol or Peligros with the subsequent drying, the injection of boric acid powder. Granulation burn the Liapis, chrome or trichloroacetic acid.
Operations on bpts mainly use two types: cut it to ensure drainage of pus in acute purulent otitis media (see Paracentesis) and plastic surgery recovery intact tympanic membrane - myringoplasty (see Tympanoplasty).
Artificial eardrum. Persistent dry perforation bpts, often remaining after suffering a chronic or acute inflammation of the middle ear, leads to a lowering of the hearing and serves as an entrance gate for the infection in the tympanic cavity. In this regard, for the closure of the perforation tried to use different materials: sheet from chicken eggs, thin rubber, etc. These primitive dentures often cause irritation of the middle ear and come unstuck. To improve hearing in many cases successfully used soaked in liquid oil on a cotton ball, which is placed in the tympanic cavity to the area labyrinth Windows. Moist environment promotes the transmission of sound vibrations to the inner ear. The disadvantage cotton prosthesis that it must be changed frequently, otherwise he also suppurate. The best results are plastic sluhovosstanavlivayuschie operations.