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 Respiratory Olfactory VestibuleAnterior nares (nostrils)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

– SkinTurbinates: 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