NOSE AND PARANASAL AIR CAVITIES

NOSE AND PARANASAL AIR CAVITIES

Nasal Septum and Lateral Wall of the Nose

The nasal septum is a cartilaginous and bony structure that separates the two nasal cavities. The lateral wall of the nose is formed by the turbinate bones and the nasal conchae.

• The nasal septum is composed of:
  • Perpendicular plate of ethmoid bone
  • Septal cartilage
  • Vomer bone
• Blood supply:
  • Septal branch of the superior labial artery
  • Septal branch of the sphenopalatine artery
• Nerve supply:
  • Olfactory nerves
  • Anterior ethmoidal nerve
  • Sphenopalatine ganglion
• Features:
  • Nasal conchae: scroll-like bones that increase the surface area of the nasal cavity
  • Turbinate bones: long, thin bones that extend from the lateral wall of the nasal cavity

Paranasal Air Sinuses

Paranasal air sinuses are air-filled cavities in the bones of the face. They are lined with mucous membranes and are involved in the production of mucus.

• The paranasal air sinuses are located in the following bones:
  • Frontal sinus: in the frontal bone
  • Maxillary sinus: in the maxilla bone
  • Ethmoid sinus: in the ethmoid bone
  • Sphenoid sinus: in the sphenoid bone
• Blood supply:
  • Frontal sinus: anterior ethmoidal artery
  • Maxillary sinus: sphenopalatine artery
  • Ethmoid sinus: anterior ethmoidal artery
  • Sphenoid sinus: sphenopalatine artery
• Nerve supply:
  • Olfactory nerves
  • Anterior ethmoidal nerve
  • Sphenopalatine ganglion
• Features:
  • Mucous membranes: produce mucus that helps to humidify the air
  • Cilia: move the mucus towards the nasal cavity
  • Mucous glands: produce mucus that helps to trap dust and other particles

Applied Anatomy

• The nasal septum and lateral wall of the nose are involved in the production of mucus, which helps to humidify the air and trap dust and other particles.
• The paranasal air sinuses are involved in the production of mucus, which helps to humidify the air and trap dust and other particles.
• The nasal conchae and turbinate bones increase the surface area of the nasal cavity, which helps to warm and humidify the air.
• The sphenopalatine ganglion is involved in the transmission of nerve fibers that regulate the production of mucus and the contraction of smooth muscle in the nasal cavity.