Card Set Information

2012-12-04 16:55:40

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  1. Helix
    An archway defining the top of your outer ear
  2. Scaphoid fossa
    flat area under the helix
  3. Tragus
    on the face-side of the opening
  4. Ear lobe
    epithelial cells ready for piercing
  5. External auditory meatus
    • Slightly curved upward
    • Entrance to the temporal bone
    • Water and foreign matter flows outward with the help of gravity
    • Cilia and sebacious glands produces cerumen
  6. Tympanic membrane
    • Positioned obliquely 140 degrees
    • Concave drum stretched across and attached to a bony frame that sits in a groove in the temporal bone
    • The membrane is three layers thin
    • Most membrane is tense but the top part is loose¬†
  7. Cone of light
    membrane is smooth, translucent and grayish and one area reflects light
  8. Umbo
    whitish streak(Shadow) from the center of the handle of the malleus
  9. Epitympanic recess
    • Air filled cavity which extends above the tympanic membrane
    • Filled by the malleus and incus
  10. Tympanic aditus
    hole in the posterior wall which opens to the mastoid air cells creating a potential breeding ground for infection
  11. Tegmen Tympani
    Roof of the cavity is paper thin
  12. Oval window
    • entrance to the inner ear
    • covered by the oval footplate of the staples
  13. Promontory
    bony projection below the oval window
  14. Round window
    below the promontory which is covered by a membrane
  15. Eustachian tube
    • ends in the nasopharynx
    • the tube slopes down, anteriorly and medially
    • can easily be clogged in the nasopharynx
    • brings the air pressure of the nasopharynx to the middle ear so the air pressire on both sides of the tympanic membrane are equal
    • facilitates proportional vibration of the ear drum
  16. Malleus
    has a head a neck and a long handle
  17. Incus
    has two legs one shorter than the other and an articular surface where the head of malleus swivels
  18. Stapes
    has a head two legs and an oval footplate at the bottom
  19. The series of ligaments that hold ossicles in place loosely
    • Superior malleolar ligament
    • Lateral malleolar ligament
    • Anterior malleolar ligament
    • Posterior incal ligament
    • Elastic annular ligament
  20. Tensor tympani
    • muscle of the middle ear
    • Origin: septum canalis musculotubari
    • Insertion: handle of the malleus
    • Action: draws the malleus medially and anteriorly tensing the tympanic membrane
  21. Stapedius
    • muscle of the middle ear
    • Origin: posterior wall of the middle ear
    • Insertion: tendon on the head of the stapes
    • Action: draws the stapes posteriorly
  22. Acoustic reflex
    Tensor Tympani pulls the malleus forward and the stapedius pulls the stapes backward separating the ossicular chain. Their action begins to protect the delicate ossicles from the intense vibrations of such a loud sound