Ear

Cartilaginous exterior ear is known as?

Auricle/pinna

Components of external ear?

Auricle/pinna

External auditory meatus/ear canal

What kind of cartilage makes up the auricle?

Elastic

Innervation of auricle?

Anterior to meatus: *auriculotemporal nerve* from mandibular trigeminal *V3*

Posterior to meatus, helix, antihelix & lobule: *great auricular nerve* from *C2-3*

What does the external auditory meatus pass through?

Tympanic part of temporal bone

What lines the external auditory meatus?

Outer third: cartilaginous, skin continuous with auricle

Inner third: bony, thin skin continuous with tympanic membrane

What produces earwax?

Ceruminous and sebaceous glands of cartilaginous part of external auditory meatus

What is earwax also known as?

Cerumen

Innervation of external auditory meatus?

Auriculotemporal, branches of Vagus

What can be seen through the tympanic membrane on otoscopy? Orientation?

Handle & lateral process of malleus.

Lateral process always points anterior.

What is the centre of the tympanic membrane known as?

Umbo

In what bone is the middle ear?

Petrous part of temporal

What is inside the middle ear?

> Ossicles

> Stapedius

> Tensor tympani

> Chorda tympani

What are the ossicles in order?

Malleus, incus, stapes

What joints are between the ossicles?

Synovial

What does the base of the stapes attach to?

Oval window

What are the two ends of the cochlea?

Oval window - stapes

Round window

Function of stapedius?

Dampens vibrations of stapes to control amplitude of vibrations reaching inner ear

Innervation of stapedius?

Facial nerve

Do the ends of the conchae vibrate in or out of phase?

Opposite phases

Where does the Eustachain tube connect?

Anterior wall of middle ear

Nasopharynx at level of inferior meatus

How else does the middle ear communicate with the outside?

With mastoid air sinuses through mastoid antrum

What additionally innervates the tympanic membrane?

Facial nerve

What is significant about the tympanic membrane in children?

It is significantly closer to the surface

What do you use to examine the ear?

Auriscope