External Nose Bony External Nose Cartilaginous Dangerous area
External Nose- Bony
External Nose- Cartilaginous
• Dangerous area of the face • Dangerous area of the nasal cavity
Nasal cavity • Medial wall (Septum) • Lateral wall • Roof • Floor Ø Respiratory Ø Olfactory Ø Vestibule ü Anterior nares (nostrils) ü Posterior nares (choanae)
Vestibule
Nasal septum • Bony – – – Perpendicular plate of ethmoid Perpendicular plate of Vomer Nasal crest of maxilla Nasal crest of palatine bone Rostrum of sphenoid • Cartilaginous – Quadrilateral cartilage • Membranous – Forms the columella
Lateral wall of nasal cavity
Ostio-meatal Complex (OMC)
Mucosa • Respiratory area – Pseudo stratified ciliated columnar epithelium – Mucous glands and goblet cells • Olfactory area • Vestibule – Skin ü Turbinates: Vasular with submucosal sinusoids (Cavernous tissue)
Blood supply
Little’s area • Caudal part of the nasal septum which has a rich submucosal arterial network: Septal branches of – – Anterior ethmoidal Sphenopalatine Greater palatine Superior labial • Prone for drying effect of inspired air and to microtrauma due to picking of the nose • Commonest cause and site of epistaxis in children • DD: Bleeding from retrocolumellar vein
Sphenopalatine artery is considered as THE artery of epistaxis
Nerve supply • Maxillary N – Sphenopalatine – Lesser and greater palatine • Anterior ethmoidal N • Olfactory • Autonomic- Vidian N
Lymphatic drainage • Anterior part – Submandibular lymph nodes • Posterior part – Retropharyngeal lymph nodes – Jugulo-digastric lymph nodes
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