1. The Outer Ear SPA 4302 Summer 2007

2. Development of the Outer Ear About __________ after conception the pharyngeal arches develop (bulges on the area of the embryo that will later develop into the head and neck) As many as ____ all separated by grooves and clefts First three: –__________ arch –____________________ arch

3. Development of the Outer Ear Each of the arches has three layers –_______________ (outer layer) –_______________ (middle layer) –_______________ (inner layer) Each arch contains four components: –An artery, muscle and cartilage (from mesoderm) –Nerve (from _______________) Aurical develops from the first 2 pharyngeal arches EAC develops from the first pharyngeal groove TM develops from ______________: inner layer from endoderm, middle layer from mesoderm, and outer layer from ectoderm

4. External Auditory Canal lateral portion-__________ medial portion-_________ lined with epidermal (skin) tissue hairs grow in lateral part cerumen (ear wax) secreted in lateral part. Usually curved.

5. Outer Ear Functions 1 Amplification / Filtering -- 1500 to 7000 Hz increased by ________________ -- produced by resonance of Concha (_______ kHz) & E.A.Canal (_____________ Hz)

6. Outer Ear Functions 2 Protection -- medial displacement of ___________ -- curvature of canal -- _____________ -- cerumen -- _____________

7. Outer Ear Functions 3 Localization -- The ability to _________________ ____ of a sound source

8. Otoscopy Viewing outer ear and TM Looking for: _____________, Evidence of infection Other __________

9. = Annulus Lateral Process (Malleus) Malleus Manubrium Umbo Cone of Light

10. Epidermal migration produces “wrinkles”

11. Disorders of the Pinna: Microtia- ___________________________ Anotia- ____________________________ Congenital malformation associated with syndromes and disorders _____________- surgery performed to correct a pinna that either protrudes markedly from head or is pinned to closely

12. Disorders: Blockage: with earwax, foreign bodies, pus. Otitis Externa: ________________. –Fungal or Bacterial in origin. –More frequent in ears with small canal openings that cannot dry out as easily. –This is also sometimes a problem for people wearing _____________-.

13. Otitis Externa

14. Cerumen

15. A Cerumen Tunnel

17. Car Accident Victim Who just didn’t “feel right” afterward…

18. Another Foreign Object

19. Exostoses: Benign bony growths in the outer ear canal Contrast with Osteomas

21. A False Tympanic Membrane A layer of dead skin cells builds up in persons who use earplugs or some hearing aids frequently

22. Injuries to Ear Canal

23. A Q-tip Victim

24. Squamous Cell Cancer

26. Malformations: congenital, traumatic or surgical. ______________: external ear is small, malformed ______________: ear canal is closed off. Post-cancer surgery.

27. Congenital Malformation

28. Microtia

29. Anotia: Pre- and Post-Op

30. Mastoiditis

31. Hearing Loss accompanying these disorders: Blockage or atresia: – moderate ________________ hearing losses. –usually medically or surgically treatable. –additional HL if _______________--associated problems w/ cochlea Surgical or traumatic: –___________- frequency conductive. –prosthetics available, expensive.