The Outer Ear

What does medial mean?

Toward the midline

What does lateral mean?

Away from the midline

What does anterior mean?

Towards the front

What does posterior mean?

towards the back or rear of the structure

What does inferior mean?

Lower or below

What does superior mean?

Above

What is the auricle/pinna?

The cartilaginous protruding structure

What is the purpose of the auricle/pinna?

To funnel sounds toward the external auditory meatus and help with sound localization

What is the helix portion of the auricle?

Cartilaginous fold

What is the scaphoid fossa portion of the auricle?

The indentation inferior to the helix

What is the antihelix portion of the auricle?

The protrusion inferior to the helix and within the concha

What is the cymba concha portion of the auricle?

The spot that is inferior to the antihelix but superior to the crus of the helix

Thinking of piercings, how would you describe the cymba concha?

The bottom portion of a rook piercing

What is the cavum concha portion of the auricle?

The bowl-like structure in the middle of the ear

What is the antitragus portion of the auricle?

The area superior to the lobe, but inferior to the cavum concha, almost like a protrusion of the lobe

What is the lobe portion of the auricle?

The most inferior portion of the ear that is squishy

What is the intertragal notch portion of the auricle?

The little curve inferior to the tragus, right before the EAM

What is the tragus portion of the auricle?

The hard and bendy protrusion of the medial auricle

What is the crus of helix portion of the auricle?

The hard and protruding curve that is inferior to the helix and in the medial part of the ear

What is the triangular fossa portion of the auricle?

The indentation of the antihelix that is inferior to the helix

What are hillocks?

7 small, rounded lumps of tissue that develop from the first two pharyngeal arches during embryonic development around the fifth or sixth week of gestation

What hillocks are a part of the first branchial arch?

1, 2, and 3

What hillocks are part of the second branchial arch?

4, 5, and 6

What hillocks are part of the first branchial cleft?

7

What portion of the ear is the first arch?

The tragus

What portions of the ear are the second arch?

The helix and antitragus

What sounds are boosted by the auricle?

2k to 7k Hz

How many dB does the auricle boost the 2k to 7k range by?

2 to 3 dB

What is microtia?

Congenital deformity where the pinna is underdeveloped

Wahat is anotia?

Congenital deformity where the pinna is completely absent

What is basal cell carcinoma of the pinna?

Cancer cells on the ear

What is the external auditory meatus/canal?

The funnel of the auricle that directs sounds to the tympanic membrane and protects the tympanic membrane

Where is the EAM housed?

In the temporal bone

How long is the EAM?

About 1 inch (2.5 cm)

Is the EAM straight?

No, it is slightly curved

What are the boundaries of the EAM?

The concha and tympanic membrane

What are the portions of the EAM?

Outer 1/3 is cartilage, while the inner 2/3 is bone

What frequencies does the EAM boost?

2k to 5k Hz

What is atresia of the EAM?

Complete absence of the EAC that results in a conductive hearing loss

What is stenosis of the EAM?

Narrowing, but not complete closure, of the EAM that leads to conductive hearing loss if closure occurs or if there is blockage of the small EAM by cerumen

What is squamous cell carcinoma of the EAM?

A type of cancer that develops in the EAM, from squamous cells, which are normally found in the skin's outer layer

What are the symptoms of squamous cell carcinoma?

Otorrhea, otalgia, hearing loss, facial nerve paralysis

What is otorrhea?

Ear drainage

What is otalgia?

Ear pain

What are the two main portions of the tympanic membrane?

Pars flaccida and pars tensa

What is the cone of light of the tympanic membrane?

Reflection of any light that enters the ear canal indicates a good TM

What are the four quadrants of the TM?

Posterior superior, posterior inferior, anterior inferior, and anterior superior

How do you know if you are looking at a left or right TM?

If the manubrium of the malleus is tilted to the right (right ear) or left (left ear)

What happens if there is a foreign body in the EAM?

Swelling, hearing loss, TM rupture

What is external otitis?

Infection occurring int he skin of the EAM, caused by allergic reactions to ear plus, hearing aid ear molds, soap, or pool water

What is external otitis also known as?

Swimmer's ear

What are the symptoms of external otitis?

Otalgia, otorrhea, inflammation, and itching

What is otomycosis?

Fungal infection of the EAM

What are the symptoms of otomycosis?

Otorrhea, otalgia, itching, conductive hearing loss

What is exostoses?

Bony growths in the osseous portion of the EAM

What causes exostoses?

Repeated exposure to cold/hot water

What are the symptoms of exostoses?

Conductive hearing loss

What happens if there is ceruman blockage in the EAM?

Mild conductive hearing loss

How do you treat cerumen blockage of the EAM?

Wax-softening ear drops or removal

What are perforations of the TM caused by?

Infection, trauma, sudden pressure change

What type of hearing loss is caused by perforations of the TM?

Conductive hearing loss that varies in severity depending on the size and location of the TM

What is a myringoplasty?

Surgical repair of TM may be needed depending on the size of the perforation