Outer Ear

Audiology test 2

What two primary components consist of the Outer Ear?

Auricle/ Pina and External Auditory Canal/ meatus

What does the Pina do?

Funnels sound wave from the environment into the ear canal.

What is the Pina made up of?

Cartilage

What is the concha responsible for?

Help to l**ocalize** sound source & to **funnel** sound into the external auditory canal.

Where does the EAC begin at?

at the concha & extends medially into the temporal bone.

What does the lateral 1/3rd of EAC contain?

* Sebaceous Glands; which secrete sebum (oily, fatty substance) for cerumen production
* Hair follicles

Where does the lateral passes through? (1/3)

Cartilage

Where does the Medial passes through? (2/3)

Temporal bone

Where does the Medial 2/3rd of EAC contain?

No glands or hair follicles

What is Osseocartilaginous junction?

where the cartilaginous and bovy portions meet.

Where does the tympanic membrane marks the boarder between what?

Outer and middle ear

In a healthy ear, in which TM quadrant will you see the cone of light?

Anterior-inferior

Disorders that affect the outer and/or middle ear result in

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Conductive Hearing Loss

What are the primary functions of the outer ear?

Assist in sound localization

Boost frequencies important for speech (\~2000-7000 Hz)

Protect TM from trauma

In a healthy ear, the TM is most compliant near atmospheric pressure.

T/F

True

The tympanic membrane is comprised of how many layers?

3

What are the tympanic membrane layers?

Outer, Middle and Inner layer

Outer layer

same skin as EAC

Middle layer

tough, fibrous connective tissue

Inner layer

mucous membrane (lining of middle ear space)

Name the landmarks on the tympanic membrane

Malleus, Umbo, Annulus, Pars tensa, and Pars flaccida

how many landmarks on the tympanic membrane are they?

6

Malleus

largest bone of middle ear; embedded in fibrous portion of TM

Umbo

tip of malleus that terminates near the middle of TM

Annulus

Ring of tissue that hols the TM in position at the end of the EAC

Pars tensa

taught area of TM (largest portion) ( made up of 2 layer of skin)

Pars flaccida

area of loose tissues above the malleus

Cone of light

light reflections observed in the anterior-inferior quadrant during otoscopy

What are the 2 landmarks on the TM that are made up of two layers of skin?

Pars tensa and Pars flaccida

What does the Otoscopy allow you to see?

the outer ear and tympanic membrane

Why do we brace when doing Otoscopy?

to prevent injury to the ear canal if the patient moves

What causes underdevelopment of the Pinna or EAC?

Congenital (at birth) or Acquired (trauma, burns) Can occur in one or both ears

Name the 4 grades/levels of the microtia and atresia

Microtia, Anotia, Stenosis and Atresia

Microtia

one of both pinnae is underdeveloped

__Anotia__

Absent __pinna__

Stenosis

markedly narrow EAC

Atresia

absent EAC

T/F Is cerumen a normal by product of the healthy ear?

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True

What does the hair and cerumen help with?

Keep foreign objects (insects) from passing into the __medial (bony)__ portion of the EAC

T/F Can a fully occluding cerumen impact hearing?

True

What are the common conditions of the tympanic membrane?

Perforations, pressure equalizing (PE) tubes and Tympanosclerosis

Conductive Hearing loss Air Bone Gap will NOT exceed to what dB?

60 dB

Why is it important to protect the Tympanic membrane?

from trauma

What is the frequency for the outer ear?

Resonator for frequencies btw 200 and 7000 Hz (Speech Frequency)

Why is middle layer important?

it helps to vibrate

What does it mean when you don’t see the cone of light?

there’s something happening due to the shape