Anatomy of External Ear

What is it?

The outer, or external ear, is the visible part of the ear. It is attached to the skull and located on either side of your head.

Also called auricle
Purpose is to catch sound waves, amplify them, and send them down the ear canal to the rest of the ear.
Start of hearing process
Lateral part of ear
Formed of cartilage and ligaments
Covered by skin
Many ridges and depressions, each help with catching sound waves

Helix: outer rim of pinna
Crux of Helix: second ridge, surrounds concha
Concha: bowl of ear, leads to ear canal
Cymba: part of concha above crux of helix
Crus of anti-helix:runs from EAM to antihelix
Scaphoid fossa: between helix and antihellix
Triangular fossa: triangle ridge between the crura
Tragus: located at external edge of EAM, protective
Antitraugus: located opposite to tragus at the inferior end of the antihelix ridge
Intertragual notch: area between tragus and antitragus
Lobule: fatty tissue, inferior, where most people get piercings

(Musiek and Baran, page 46.)

Concha leads to this
Tube like
Leads/ends at tympanic membrane
Walls 1/3 cartilage with hair/hair focciles
Lined with sebaceous and ceruminous glands: secrete brown, wax-like substance called cerumen (ear wax)
Inner 2/3 by temporal bone
Tympanic portion floor and sides, sqaumous portion roof and portion of posterior wall
2.5-3 cm in length, .75cm in diameter
Canal is S shape, downward at either end
Lined with skin

(Musiek and Baran, page 47-51.)

I.Olfactory (Smell)

II.Optic (Vision)

III.Oculomotor (Eye)

IV.Trochlear (Eye)

V.Trigeminal (Somatosensory)

VI.Abducens(Eye)

VII.Facial (Taste; somatosensory)

VIII.Vestibulocochlear (Hearing/Balance)

IX.Glossopharyngeal (Taste)

X.Vagus(Sensory, motor)

XI.Accessory (head movement)

XII.Hypoglossal (tongue movement)

(Schulman, 2019.)

The ear canal is innervated by cranial nerves

Touching the canal can cause coughing, fainting, and effect the heart and blood circulation.

(Musiek and Baran, page 50-51.)

Page updated

Google Sites

Report abuse