1. Anatomy - Otolaryngology
INTRODUCTION

2. Topics to cover
• Nose and Sinuses
• Pharynx
• Epiglottis and vocal cords
• Ear - external, middle ear, mastoid

3. Nose
• Divided into external nose and nasal cavity
• External nose
• made up of bone above
• nasal bones, frontal processes of maxilla, and
nasal process of frontal bone
• cartilage below
• upper and lower lateral cartilages, septal
cartilage

5. Nasal cavity
• Extends from nares anteriorly (singular: naris) to
choanae posteriorly
• Medial wall - nasal septum (cartilage,
perpendicular plate ethmoid, vomer)
• Lateral wall - three turbinates (superior, middle,
inferior)
• Roof - cribriform plate - leads to anterior cranial
fossa
• Floor - hard palate

7. Lateral wall nose
• Middle meatus lies under middle turbinate -
opening called hiatus semilunaris into
which the maxillary, frontal, and ethmoid
sinuses drain
• Inferior meatus lies under inferior turbinate
- receives the opening of the nasolacrimal
duct

9. Roof nose
• The mucosa in the superior part of the nose
contains nerve endings from the olfactory
nerve which come through the cribriform
plate (called olfactory mucosa)
• Function of the nose:
• warm, humidify air
• filter out particulate matter from air
• mucociliary blanket

11. Sinuses
• Maxillary
• Ethmoid
• Frontal
• Sphenoid

12. Maxillary sinuses
• Located in body of maxilla
• Roof is floor of orbit, medial wall is lateral
wall of nose, floor is hard palate (teeth can
erupt into sinus)
• Opens into middle meatus through hiatus
semilunaris

14. Frontal sinus
• Contained in frontal bone, anterior to
anterior cranial foss (infections can thus
spread into brain and cause meningitis or
abscess)
• Bony septum divides two sides
• Opens into middle meatus via frontonasal
duct

16. Sphenoid sinus
• Lies within body of sphenoid bone
• Opens into sphenoethmoidal recess above
superior turbinate
• Septum separates into two sides
• Lateral wall contains cavernous sinus with
internal carotid artery and nerves
• Optic nerve runs along lateral roof

18. Ethmoid sinuses
• Contained within ethmoid bone, between
nose and orbit
• Separated from orbit by thin layer of bone
(lamina papyracea, allows spread of sinus
infection into orbit)
• Drain mostly into middle meatus
• A series of small cells

21. Pharynx
• Divided into nasopharynx, oropharynx, and
hypopharynx
• Nasopharynx -
• behind nose
• Eustachian tube orifices
• adenoids

23. Pharynx
• Oropharynx
• soft palate to upper border epiglottis
• base of tongue (with lingual tonsils)
• palatine tonsils
• median/lateral glossoepiglottic folds
• vallecula is area just lateral to median GEF
• two folds of mucus membrane near tonsil (anterior and
posterior tonsillar pillar aka palatoglossal and
palatopharyngeal arch)

25. Hypopharynx
• Behind and lateral to larynx
• lower border is cricoid cartilage (opening
into esophagus)
• Epiglottis is anterior fold of mucosa and
cartilage, flops down over larynx to prevent
aspiration during swallowing
• Aryepiglottic folds, pharygoepiglottic folds
• Piriform sinuses are lateral to larynx

27. Vocal cords
• True vocal cords - nonkeratinizing
squamous epithelium, over muscles that can
move and tense cord
• False vocal cords - aka vestibular folds -
above true vocal cords
• Ventricle is between the two
• Vocal cords attached to thyroid cartilage
anterior, arytenoid cartilage posterior

29. Ear
• The external ear consists of the helix, the
antihelix, the tragus, and the lobule
• The external auditory canal is cartilaginous
in the outer 1/3 and bony in the inner 2/3
• The lymphatic drainage of the EAC is
anteriorly to the parotid gland
• Nerves that supply the EAC/ear: VII, X,
Cervical plexus

31. Tympanic membrane
• Pearly gray fibrous membrane
• Concave laterally
• Umbo is depth of concavity where the
handle of the malleus attaches to the TM

33. Middle Ear
• Roof: tegmen tympani (--> MCF)
• Floor: bone separates from IJV
• Anterior: bone separates from ICA
• two openings anteriorly - Eustachian tube, tube
for tensor tympani muscle
• Lateral: tympanic membrane
• Medial: promontory, oval window, round
window (lead into inner ear)

35. Middle ear
• Posterior: opening into mastoid air cells
(aditus ad antrum)
• Ossicles:
• malleus
• incus
• stapes
• Tensor tympani, stapedius muscles