Fossa
Trench
Ditch
Depression
Outer Ear Comprised of:
Landmarks of Pinna
Helix Antihelix Crura of Antihelix Helix Crus Scaphoid Fossa Triangular Fossa Concha Cymba Concha Covum Tragus Antitragus Intertragal Notch Lobule
Function of the Auricle / Pinna
Catch & Funnel Sound
Auricle and Pinna is Made of :
Cartilage Epithelial Proper
Pinna / Auricle Attachment Points
Posterior - Mastoid Process
Anterior - Zygomatic Arch
Auricle / Pinna Attachments
Auricle Muscles
Anterior, Superior & Posterior
Auricular Ligaments Attach
Anterior & Posterior
Auricular Muscles are:
Vestigial
The EAM / EAC
length
resonant frequency
angle
~ 1 inch
~ 3.300 Hz
angled down in adults and up in children
EAM / EAC outer 1/3 consists of:
cartilage sebaceous glands ceruminous glands epithelial proper hair
EAC / EAM inner 2/3 consists of :
bone
epithelial proper
Osseocartilaginous Junction
Where the inner & outer EAC join
Condyle
Protrusion of the mandible & rests below the Osseocartilaginous junction
Temporomandibular Joint TMJ
When the jaw is misaligned and can cause Otaliga ..ear pain in adults
EAC / EAM Innervation
Trigeminal - Superior / Posterior
Vagus - Inferior / Anterior
Stimulation of Vagus - Cough reflex
Resonant Properties of EAC Causes
Amplification of High Frequencies
Decrease of Low Frequencies
TM Boundary
Common boundary between outer and middle ear
Upper 1/3 (30mm)
Pars Flaccida
Lower 2/3 (60mm)
Pars Tensa
TM Layers
3 Layers (1/10 mm thick)
Epithelial proper layer , rich blood supply
Fibrous Layer
Mucus Membrane Layer
TM is encircled by
embedded in fibrous portion by
Tympanic Annulus
Malleus Attachment
Manubrium of Malleus points to:
1: 00 in Rt ear
11: 00 in Left ear
The Umbo is
Tip of the Malleus, the area of greatest concavity