Anatomy of the Nose and Nasal Cavity

External Nose

• Parts: Includes the visible portion of the nose.
• Clinical Correlations: Rhinophyma (enlarged sebaceous glands).
• Arteries: Dorsal nasal (ophthalmic artery), infraorbital (maxillary artery), alar & septal (facial artery).
• Sensory Nerves: External/dorsal nasal and infratrochlear (ophthalmic nerve); infraorbital (maxillary nerve).
• Muscles: Procerus (wrinkles), nasalis (compresses nasal aperture), alar part of nasalis (dilates), depressor septi nasi (dilates anterior aperture); all innervated by facial nerve.

Nasal Cavity

• Divisions: Vestibule and nasal cavity proper.
• Vestibule: Contains vibrissae (coarse hairs), sweat glands, sebaceous glands; bordered superiorly by the limen nasi and medially by the columella.
• Clinical Correlations: Deviated nasal septum (DNS), correctable via submucous resection (SMR) or septorhinoplasty.
• Conchae: Superior and middle (ethmoid bone), inferior (independent bone), supreme (sometimes present).

Meatuses

• Inferior meatus: Nasolacrimal duct opening.
• Middle meatus: Bulla ethmoidalis (middle ethmoidal air cells), hiatus semilunaris (infundibulum of maxillary sinus, anterior ethmoidal air cells, frontal sinus opening).
• Superior meatus: Sphenoidal sinus opening.

Nasal Cavity Lining & Arterial Supply

• Lining: Olfactory region (olfactory epithelium), respiratory region (pseudostratified ciliated columnar epithelium).
• Arterial Supply (Lateral Wall): Anterosuperior (anterior & posterior ethmoidal arteries), anteroinferior (alar branch of facial artery & greater palatine artery branches), posterosuperior (sphenopalatine branch of maxillary artery), posteroinferior (greater palatine branch of maxillary artery). Supplied by branches of ophthalmic, maxillary, and facial arteries.
• Venous Drainage (Lateral Wall): Facial vein, retropharyngeal veins, pterygoid venous plexus.
• Lymphatic Drainage (Lateral Wall): Submandibular nodes, retropharyngeal and upper deep cervical lymph nodes.

Little's Area & Nasal Septum

• Little's Area (Kiesselbach's plexus): Formed by septal branches of anterior ethmoidal, sphenopalatine, greater palatine, and superior labial arteries; common site of nosebleeds.
• Arterial Supply (Nasal Septum): Anterosuperior (anterior & posterior ethmoidal arteries), posteroinferior (sphenopalatine & greater palatine arteries), mobile part (septal branches of superior labial artery).
• Venous Drainage (Nasal Septum): Superior ophthalmic vein, pterygoid venous plexus, internal jugular vein (via facial vein).
• Lymphatic Drainage (Nasal Septum): Submandibular lymph nodes, retropharyngeal lymph nodes.
• Nerve Supply (Nasal Septum): Olfactory nerves (olfactory zone), ophthalmic and maxillary branches of trigeminal nerve (remaining zones).

Functions of the Nose

• Respiration
• Olfaction (sense of smell)
• Protection of lower respiratory passages
• Conditioning inspired air (warming, humidifying, filtering)
• Vocal resonance
• Nasal reflex functions (e.g., sneezing)