Applied Anatomy of Applied Anatomy of EAREAR

External EarExternal Ear

What type of cartilage Pinna is made What type of cartilage Pinna is made up of ?up of ?

ElasticElastic HyallineHyalline

What is the length of Ext Auditary What is the length of Ext Auditary Meatus [How deep is the TM]?Meatus [How deep is the TM]?

1 inch1 inch 1.5 inches1.5 inches 2 inches 2 inches

Tympanic MembraneTympanic Membrane

The size of TM isThe size of TM is

1x0.5 cm1x0.5 cm 1x1cm1x1cm 1x0.8 cm1x0.8 cm

How far is TM from external opening of the How far is TM from external opening of the earear

1 inch1 inch 1.5 inches1.5 inches 2 inches2 inches

How thick is TM ?How thick is TM ?

Approx 1 mmApprox 1 mm Approx 0.5 mmApprox 0.5 mm

TM lies at TM lies at

At Right angle to the External At Right angle to the External Auditary MeatusAuditary Meatus

ObliquelyObliquely

SummarySummary

Bulk of Ear is embedded in Temporal Bulk of Ear is embedded in Temporal bonebone

Ear consists of 3-parts: Ext Ear, Middle Ear consists of 3-parts: Ext Ear, Middle Ear and Internal EarEar and Internal Ear

External ear consists of PINNA and EAMExternal ear consists of PINNA and EAM EAM is 1-inch long and S-shaped and is EAM is 1-inch long and S-shaped and is

closed by TM at the other endclosed by TM at the other end Middle Ear lies next to TMMiddle Ear lies next to TM

Middle contains Ossicles [Malleus,Incus and stapes] Middle contains Ossicles [Malleus,Incus and stapes] which transmit sound to Internal earwhich transmit sound to Internal ear

In addition to Ossicles , FACIAL NERVE passes through In addition to Ossicles , FACIAL NERVE passes through itit

Middle Ear is filled with AIR ;Eustacean tube maintains Middle Ear is filled with AIR ;Eustacean tube maintains the Air pressure connecting it to Ext Atomospherethe Air pressure connecting it to Ext Atomosphere

Internal ear lies protected in petrous part of Temporal Internal ear lies protected in petrous part of Temporal BoneBone

It consists of COCHLEA [ for hearing] and LABARYNTH It consists of COCHLEA [ for hearing] and LABARYNTH for Balance; Vestibulo-cochlear nerve transmits sound for Balance; Vestibulo-cochlear nerve transmits sound and balance information to Brain Stemand balance information to Brain Stem

MASTOID is the bony prominence just behind Ext Ear.MASTOID is the bony prominence just behind Ext Ear.