Outer Ear Disorders

Question 1

What part of the auditory system covers the peripheral portion?

Answer 1

• Outer ear
• Middle ear
• Cochlea
• Auditory nerve

Question 2

What part of the auditory system covers the central part?

Answer 2

*Cochlear Nucleus
*Superior Olivary Complex
*Lateral Lemniscus
*Inferior Colliculus
*Medial Geniculate Body
*Auditory Cortex
*Association Areas

Question 3

What are the two major features of the outer ear?

Answer 3

Pinna and the external auditory canal

Question 4

What are the primary functions of the outer ear?

Answer 4

Sound localization and directing sounds into the system using acoustic energy

Question 5

What are the different anatomical regions of the outer ear?

Answer 5

*Pinna
*Tragus
* Helix
* Antihelix
* Triangular Fossa
* Scaphoid Fossa
* Concha
* Lobe
* External auditory canal

Question 6

The pinna is responsible for an approximate ___ dB boost in the auditory signal around ______ Hz.

Answer 6

10 dB boost (gain)

5000 Hz (genereally mid-high frequencies)

Question 7

Any pathology, absence, or malformation of the outer ear may result in some loss of hearing acuity in the ______

Answer 7

2000- 5000 hz

Question 8

The pinna receives blood supply from the ___________ , basically from two branches ____ and ______.

Answer 8

external cartoid artery

superifical temporal artery (STA) and posterior auricular artery (PAA)

Question 9

The cartilaginous and bony tube is typically closed off at one end with a resonance of ____ wavelength frequency

Answer 9

1/4 wavelength

Question 10

The ear canal provides about a ____ dB boost around _____ Hz in adults

Answer 10

12 dB

3000 Hz

Question 11

What are some protective functions of cerumen?

Answer 11

Antifungal and antibacterial
keeps ear canal lubricated

pH level creates a toxic environment for most insects

Question 12

Atresia

Answer 12

cogential malformation of the external auditory cnal due to interrupted development of the outer ear

Symptoms: visible abnormalities (often in conjunction with microtia and other craniofacial abnormalities
*speech and language delays
*possilbe inflammation, otalgia, and/or otorrhea

Dx: small ECV, may have CHL pattens with ART, audio, and OAEs reduced or absent

Question 13

What are the different grades of Atreisa?

Answer 13

Type A: meatal atresia; smaller than normal but anatomically appears mostly normal

Type B: partial atresia; part of ear appears normal (canal may be open, reduced or completely closed)

Type C: total atresia (aural atresia); peanut shaped canal with no canal

Type D: hypopneumatic atresia (anotia); complete absence of external ear and canal

Question 14

Furunculosis

Answer 14

raised, reddish lesions at the base of hair follicles on the outer EAC

symptom: otalgia

dx: otosopy appears abnormal but everything else is WNL

Question 15

Herpes Zoster Oticus (shingles)

Answer 15

lesions/blisters on pinna due to chicken pox virus and swelling to face

sym.: otalgia, facial weakess, erythema, hearing loss

dx: otoscopy abn., elevated ART, audio SNHL, oaes consisent with OAEs

Question 16

Microtia

Answer 16

Small or misshape on pinnna

anotia: complete absence of pinna

usually co-occurs with other anomalies and cranofacial abnormalities

Question 17

Otitis externa

Answer 17

Infections of the outer ear caused by bacteria or fungus which can progress to necrotizing

symptom: otalgia, otorrhea,

dx: may be normal or have chl patterns

Question 18

Osteoma

Answer 18

pedunculated benging tumors in the osseous portion of the EAC
**think benign bone tumor

dx: normal but can also cause chl patterns

Question 19

Perichondritis

Answer 19

Infection of pinna resulting typically from trauma

Symptoms: otalgia, erythema, edema

dx: usually normal

Question 20

Cerumen removal contraindications

Answer 20

surgical ear

blood thinners

diabetic