2 External nose Root and tip Nostrils (nares): are the external orifices of the nose. Bounded laterally by the ala and medially by the nasal septumNasal skeleton:Nasalis bonesFrontal processes of the maxillaeNasal part of the frontal boneUpper and lower nasal cartilagesSeptal cartilage
6 Nasal cavity From the nostrils till the choana Divided into right and left by the nasal septumFloor: palatine process of the maxilla and horisontal plates of the palatine bonesRoof: body of the sphenoid, cribriform plate of the ethmoid, frontal bone, nasal bone, nasal cartilages
17 The middle meatus is continuous in front with a depression called the atrium. Within the nostril in front of the atrium is the vestibule. It is lined by modified skin and short curved hair called the vibrissae
22 The mucous membrane lines the nasal cavity except the vestibule The mucous membrane lines the nasal cavity except the vestibule. There are two types of mucous membranes:1. Olfactory mucosa2. Respiratory mucosa
23 1. olfactory mucous membrane: lines the superior surface of the superior concha and the sphenoethmoidal recess. It also lines the corresponding part of the nasal septum
24 The axons of the fibers pass through the openings in the cribriform plates of the ethmoid bone and end in the olfactory bulb
25 2. The respiratory mucous membrane: Lines the rest of the nasal cavity.Its function is to warm, moisten and clean the inspired air.Warming: venous plaxus in the submucosaMoisture: mucous by the glands and goblet cellsCiliary action….
26 Nerve supply of the nasal cavity The olfactory nerve: arise from special olfactory cells in the olfactory mucous membraneNerves of general sensation: derived from opthalmic and maxillary divisions of the trigeminal nerve:- anterior ethmoid nerve- nasal, nasopalatine , greater and lesser palatine nerves of the pterygopalatine ganglion
38 Kiesselbach area (Little area) of the nasal septum The area of the septum about 1 cm posterior to the nares. It is very rich in blood supply and a common site of epistaxis.Anterior ethmoid arterySphenopalatine arteryGreater palatinal arterySeptal branch of facial artery
42 Paranasal sinusesCavities found in the interior of the maxilla, frontal,sphenoid and ethmoid bones.Lined with mucoperiostium and filled with air.The mucous produced by the glands in the mucous membranes is moved into the nose by the ciliary action of the columnar cells.The function of the sinuses is to act as resonators of the voice and to reduce the weight of the skull.
55 Osteomeatal complexThe most commonly infected structure in the sinusesCan be obstructed and inflammed easily with even minimal edemaCan not be examined by anterior rhinoscopy but with endoscopyCan not be evaluated by conventional radiology but needs CT
56 Obstruction of the osteomeatal complex Anatomic variationsForeign bodyMucociliary dysfunctionAllergyInfectionsLocal inflammation↓Obstruction of the osteomeatal complexSinusitis
57 FESSThe target of Functional Endoscopic Sinus surgery (FESS) is to remove the pathology of the osteomeatal complex to maintain normal ventilation and drainage to the sinuses.