1. Six walls

2. Contents

Functions: ① Adjust the tympanic air pressure to maintain a balance between the pressure inside and outside the tympanic membrane; ② Remove tympanic secretions; ③ Prevent pharyngeal fluid from entering the tympanic cavity; ④ Sound blocking and silencing effects

The air-containing cavity above and behind the tympanum is the hub where the tympanum and mastoid air cells communicate.

It is not yet developed at birth and usually develops from the sinus tympanum to the mastoid after the age of 2 years.

Vestibule, osseous semicircular canals, cochlea

Utricle and macula utriculi, saccule and macula sacculi, membranous semicircular canals and crista ampullaris

1. The sound frequency that the human ear can hear is between 20 and 20,000 Hz. Those with <20 Hz are called infrasound, and those with >20,000 Hz are called ultrasound.

2. Physiological functions of the ear

3. Hearing examination

1. Rinne test (RT): The purpose is to compare the length of air conduction and bone conduction in the subject's ear; test the bone conduction hearing first. Once the subject's ear cannot hear the sound of the tuning fork, immediately test the ipsilateral air conduction hearing. If you can hear again at this time, it means air conduction (AC) > bone conduction (BC) (in terms of conduction time), and the test is called positive; if you cannot hear, you should knock the tuning fork again and measure the air conduction hearing first. Listen again in time, and immediately measure the bone conduction hearing in the same ear. If you can hear again at this time, it means bone conduction > air conduction, and the test is said to be negative.

2. Weber test (WT): The purpose is to compare the bone conduction hearing of the subject's two ears; after knocking the tuning fork, place it at any point on the craniofacial midline, and ask the subject to identify which side the tuning fork sound is deflected to.

3.Schwabach test (ST): The purpose is to compare the bone conduction hearing of the subject and normal people; first try the bone conduction hearing of the normal person. When the person can no longer hear the sound of the tuning fork, quickly move the tuning fork to the sinus area of ​​the ear of the subject. Then use the same method to test the test ear first, and then move to the normal person; if the bone conduction of the test ear is extended, the test is positive.

4.Gellle Test (GT):

1. Application: Understand the hearing sensitivity of the subject's ear, estimate the degree of hearing damage, and initially determine the type of deafness and the location of the lesion

2. Pure tone hearing threshold test

3. Pure tone suprathreshold function test: It has certain reference value in identifying cochlear deafness and neurological deafness.

1. Tympanometry: The curve is A-shaped in people with normal middle ear function; Type As is more common when the activity of the middle ear sound transmission system is obviously limited, such as otosclerosis, fixed ossicles, and obvious thickening of the tympanic membrane; Type Ad is more common when the ossicles are When the activity of the middle ear sound transmission system is significantly increased, such as chain interruption, tympanic membrane atrophy, healing perforation, abnormal opening of the Eustachian tube, etc.; Type B is more common in patients with tympanic effusion and obvious middle ear adhesions; Type C is more common in patients with Eustachian tube dysfunction, negative tympanic pressure

2. Acoustic stapedius reflex

1. Otoacoustic emissions (OAEs): refers to the sound energy originating from the cochlea and can be recorded in the external auditory canal; including spontaneous otoacoustic emissions (SOAEs) and induced otoacoustic emissions (EOAEs)

2. Application: ① Hearing screening of infants and young children; ② Early quantitative diagnosis of cochlear deafness; ③ Differential diagnosis of cochlear deafness and retrochlear deafness; ④ Analysis of retrocochlear auditory pathway lesions

1. Electrocochleograph (ECochG): differential diagnosis of various types of deafness on the auditory nerve and its peripheral auditory conduction pathways; objective evaluation of treatment effects

2. Auditory brainstem response audiometry (ABR): ① Determine high-frequency hearing threshold; ② Newborn hearing screening; ③ Differentiate organic deafness and functional deafness; ④ Diagnose cerebellopontine angle space-occupying Lesions; ⑤ Diagnosis, localization, and curative effect selection of various central nervous system diseases

1. Static balance examination: Romberg test, static posturography

2. Dynamic balance examination: star-shaped footprint walking test, dynamic posture tracing method

3. Limb test: finger passing test, writing test

4. Coordination function test: finger-nose test, heel-knee-shin test, rapid rotation test

1. Spontaneous nystagmus examination method

2. Opto-oculomotor system examination methods: saccade test, smooth tracking test, optokinetic nystagmus examination, gaze nystagmus examination

3. Vestibular eye function test: Check the function of the semicircular canals

4.Others

Sudden earache, ear canal bleeding, ear fullness, hearing loss, tinnitus; dizziness and nausea may occur when combined with inner ear damage

Otoscope: Multiple slit-like perforations of the tympanic membrane, with blood stains/scabs on the edge of the perforation/in the ear canal; clear water-like fluid may flow out when the temporal bone fracture is accompanied by cerebrospinal fluid leakage

Hearing Test: Conductive/Mixed Hearing Loss

Such as headache, coma, shock after trauma

Bleeding: blood can overflow through the external auditory canal, nose, and pharynx. Cerebrospinal fluid leakage: otorrhea and rhinorrhea.

Hearing loss and tinnitus: longitudinal fracture → damage to the middle ear → conductive hearing loss, low-frequency tinnitus; transverse fracture → damage to the inner ear → sensorineural hearing loss, high-frequency tinnitus

Dizziness: transverse fracture → damage to inner ear

Facial paralysis: transverse fracture → damage to the intracranial segment of the facial nerve to the internal auditory canal → poor prognosis and difficult recovery

Severe pain (when the boil is on the front wall, it can be aggravated by chewing/talking), pus discharge from the external auditory canal (mixed with blood, but no mucus → different from otitis media), swollen and painful lymph nodes in front/back of the ear; in severe cases, it may General discomfort and elevated body temperature

There is localized redness and swelling in the cartilage of the external auditory canal, and there may be a white pus head in the center; there will be a fluctuating feeling after maturity; the pus will be very thick after discharge.

There is traction pain in the auricle and tenderness in the tragus; the postauricular groove disappears and the auricle stands up (the furuncle on the posterior wall of the external auditory canal spreads to the back of the ear)

Blood routine: WBC↑

Early stage: Ichthyostatin, detumescence ointment; local physical therapy

Progressive stage: Immature boils are contraindicated for incision; if there is a white purulent head at the tip, it can be gently punctured and the purulent head is pressed out; if there is obvious fluctuation, incision and drainage can be performed (the incision should be parallel to the longitudinal axis of the external auditory canal); the boil has ulcerated on its own. Hydrogen oxygen can be used in case of rupture

Rinse with water and place for drainage

Oral antibiotics are required in severe cases

Acute diffuse otitis externa: early burning sensation in the ear, followed by ear swelling and pain that gradually intensifies, and discharge from the external auditory canal (from thin to thick)

Chronic otitis externa: ear itching and discomfort, with a small amount of secretions coming out from time to time; it can be acutely exacerbated

Acute diffuse otitis externa: tragus tenderness, auricle pulling pain; diffuse congestion, edema, and secretions in the external auditory canal

Chronic otitis externa: The skin of the external auditory canal is often thickened and scabs are attached (the skin appears to be bleeding after being avulsed); there may be a small amount of viscous secretions in the external auditory canal, or white bean dregs-like secretions accumulated deep in the external auditory canal.

Incomplete obstruction: mostly asymptomatic, may have local itching

Complete obstruction: ear fullness, hearing loss, pulsatile tinnitus (which can be consistent with the pulse), dizziness, earache (especially when the mandibular joint moves, after water intrusion, and when accompanied by infection)

Otoscope: There is a brown-black mass in the external auditory canal, which is hard, and there may be no gap between the external auditory canal wall and the external auditory canal wall.

Hearing test: polyconductive hearing loss

Foreign bodies that do not change shape when exposed to water: may be asymptomatic

Foreign bodies that change shape when exposed to water can quickly cause ear swelling, pain, and infection.

Live insects: unbearable itching, pain, reflex coughing, and even ringing in the ears

Otoscope: can often detect foreign bodies