Paranasal sinuses and the EarKate Dahill and Katie Joyce

Sinuses… Just hollow parts of the skull May get infected, and the infection may spread

What type of cells line the sinuses? Respiratory mucosa - ciliated pseudostratified columnar

epithelium

So, they produce mucus, which drains into…. The nasal cavity

Which sinuses don’t drain with gravity..? Maxillary

SPHENOID sinus drains to SPHENoethmOID recess Others drain to Hiatus semilunaris

Sphenoethmoid recess

Hiatus Semilunaris

Innervation All EXCEPT MAXILLARY innervated by…

CN Va

Which is innervated by.. CN Vb

Pain referral? Frontal head Maxillary – maxillary teeth

Tympanic membraneFlaccid part

Cone of light

Umbo

Tense part

Handle of malleus

3 layers of tympanic membrane:

Skin CN Vc and X

Mesoderm

Respiratory mucosa CN IX (middle ear and auditory tube)

What is in the middle ear? BONES:

Malleus Incus (Inbetween) Stapes (like a stirrup)

Muscles: Tensor tympani – connected to

malleus CN Vc

Stapedius – connected to stapes CN VII

Without muscles -> hyperacusis

Branches of the facial nerve

Pharyngotympanic OR Eustachian OR Auditory tubeWhat does it do?

Equalises pressure between middle ear and throat Drains mucus

When your ears ‘pop’ it’s your eustachian tube opening.

Which pharyngeal arches does the ear derive from?

1 & 2

What is the sensory innervation of the ear? How do you test this?

CN 8 Rinnes and Webers:

Weber;-Tuning fork on forehead and ask where patients hears the sound/vibration and does it lateralise -Normal; no lateralisation -Conduction deafness; sound lateralised to AFFECTED ear-Sensorineural deafness; sounds lateralised to NORMAL ear

Rinne;-Tuning fork on mastoid til sound stops then hold in air by EAM-Air conduction should be better than bone conduction-Conduction deafness; no note at EAM

Rinne Weber

What is the difference between conductive and sensorineural hearing loss?

Conductive loss; sound cant travel to inner ear e.g. outer or middle ear blockage

Sensorineural loss; damage to the hair cells within the cochlea or CN VIII

THE END