Nose

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  • olfactory Epithelium supplied by olfactory nerve through cribriform plate
  • fragility of cribriform palte means that injury to the brain possible through injuries to nose
  • nasal cavity serperated by perpendicular plate of ethmoid, vomer and septal cartilage
  • anterior ethmoidal nerve and artery run down top of nose
  • into nasal cavity project three conchae
    • inferior concha - supported by turbinate bone,
    • middle and superior conchae - supported by outgrowths of ethmoid bone
  • inferior meatus
    • below inferior concha
    • recieves nasolacrimal duct
    • lateral wall is medial border of maxillary sinus
  • middla meatus
    • below middle concha
    • ducts from ethmoidal air cells open onto ethmoidal bulla
    • frontal sinus open anteriorly and maxillary antrum drains posteriorly to bulla
  • supperior meatus
    • drains posterior ethmoidal air sinuses
  • sphenoidal recess
    • drains sphenoid sinus

15.5.3 Nose and Sinuses [Morph]

15.5.3.1 Olfactory nerve

[OTFA 114–116]

 Identification on a prosection of the olfactory nerve at the cribriform plate. Olfactory tract. [OTFA 114–116]

15.5.3.2 Functional Anatomy

[OTFA 48–51]

 Inferior, middle and superior conchae. Osteomeatal complex: importance of middle meatus. Maxillary, ethmoidal, frontal and sphenoidal air sinuses. Nasolacrimal duct. Role of the nose in warming, humidifying and cleansing inspired air. [OTFA 48–51] All sinuses except posterior ethmoidal and sphenoid open into the middle meatus. The osteomeatal complex in the middle meatus is the key area for endoscopic sinus surgery.

Only one structure, the nasolacrimal duct, opens into the inferior meatus.
Pharyngotympanic (Eustachian) tube.
Broad principles of blood supply, for nosebleeds (epistaxis); principles of supply by branches of maxillary, ophthalmic and facial arteries. (Little’s area (in young people).) The veins of the nose, face and sinuses have intracranial communications which may act as routes for the spread of infection (e.g. cavernous sinus thrombosis, meningitis, frontal lobe abscess).
Sinusitis. Routes of infection and drainage: relations between eye and ethmoid and frontal sinuses. Relation between teeth and maxillary antrum: teeth as source of infection. Thinness of some bones, esp. between ethmoid sinus and orbit: significance in transmission of infections. Because of their large size, the ethmoid sinuses are particularly important in children.

The ethmoid sinuses are intimately related to the orbit, the cribriform plate and the optic nerve.
 

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