1. R. Shane Tubbs, MS, PA-C, PhD
The Larynx
R. Shane Tubbs, MS, PA-C, PhD

2. 9 Cartilages 3 unpaired: epiglottis, thyroid, cricoid
3 paired: arytenoid, corniculate, cuneiform

6. vocal ligament

7. cunneiform
triticeal

8. vestibular fold
vocal ligament

9. Cartilages
Thyroid: (shield), C4-C5 hyaline, 90o male; 120o female (subpubic)
Cricoid: C6, hyaline, only complete ring therefore can compress the esophagus
Triticeal
Epiglottis: extends to C3, elastic
Cuneiform: elastic, does not contact other cartilages
Corniculate: limited function in man, elastic
Arytenoid: ½ elastic ½ hyaline
By ~age 65 thyroid, cricoid and ½ arytenoid are ossified

10. Quadrangular membrane: submucosal sheet of connective tissue
Its free inferior margin = vestibular fold
Its free superior margin = aryepiglottic fold

11. Conus elasticus:
(cricothyroid membrane and vocal ligament)

12. Three regions: vestibule (superior to false folds), ventricle (between false above true), infraglottic (folds to cricoid)
Rima (slit) glottidis between true folds
Saccule (appendix)

13. false
true

14. Larynx Innervation
superior laryngeal nerve
recurrent laryngeal nerve

15. IX

17. Muscles
Extrinsic: suprahyoid and infrahyoid
Intrinsic:

18. Most Important Muscle in the Body?
posterior cricoarytenoid

19. arytenoidius

20. lateral cricoarytenoid
thyroarytenoid
lateral cricoarytenoid

21. PCA
LCA
arytenoids
vocalis

26. The Ear

28. Auricle (Pinna)

31. EAM Innervation Anterior: auriculotemporal nerve
Posterior: CN X with some CN IX/CN VII
Reflexes: bradycardic, cough, emesis
Dentally referred otalgia

32. EAM Length: adults 2-3 cm, children ~1 cm
Medial 2/3 bony; lateral part elastic cartilage
Lined with skin, Meibomian glands
Superficial parotid lymph node just anterior to opening of EAM

34. External: auriculotemporal, X, ?VII, ?IX
Internal: tympanic plexus, VII (chorda tympani)

35. Middle Ear Features
Ossicles (covered with mucous membrane not periosteum)
Stapedius and tensor tympani
Chorda tympani
Tympanic plexus

37. Middle Ear epitympanic recess middle cranial fossa
Roof: tegmen tympani
Lateral: tympanic membrane
Medial: inner ear (promontory of cochlea; aka labyrinthine wall), facial nerve

38. Posterior wall = aditus
Anterior wall = ET, canal of tensor tympani, ICA

39. IJ (superior bulb) in floor of middle ear
ICA in anterior wall of middle ear

40. M

42. Stapedius
Inserts into the neck of stapes
Function

43. Tensor Tympani

44. Chorda Tympani 5 mm superior to SM foramen enters posterior iter
From posterior iter into middle ear
Enters anterior iter then leaves via petrotympanic fissure

45. Eustachian Tube
Posterolateral 1/3 is bony

46. Eustachian tube

47. Innervation: tympanic plexus and fibers from pterygopalatine ganglion

48. annular ligament

49. Inner Ear

50. Bony Labyrinth
oval window
vestibule
round window

51. Cochlea
Semicircular canals

52. Membranous Labyrinth Cochlear duct Semicircular ducts
Utricle and saccule (within vestibule)