1. Paranasal sinuses and the Ear
Kate Dahill and Katie Joyce

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

4. 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

5. SPHENOID sinus drains to SPHENoethmOID recess
Others drain to Hiatus semilunaris
Sphenoethmoid recess
Hiatus Semilunaris

6. Innervation All EXCEPT MAXILLARY innervated by…
CN Va
Which is innervated by..
CN Vb
Pain referral?
Frontal head
Maxillary – maxillary teeth

8. Tympanic membrane Flaccid part Handle of malleus Cone of light
Tense part
Umbo

9. 3 layers of tympanic membrane:
Skin
CN Vc and X
Mesoderm
Respiratory mucosa
CN IX (middle ear and auditory tube)

10. 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

11. Pharyngotympanic OR Eustachian OR Auditory tube
What does it do?
Equalises pressure between middle ear and throat
Drains mucus
When your ears ‘pop’ it’s your eustachian tube opening.

12. Which pharyngeal arches does the ear derive from?
1 & 2

13. 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

14. Rinne
Weber

15. 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

16. THE END