Laboratory Identifications and Relations -- Pterygopalatine Fossa


[ SBMP ] [ Skull ] [ Face ] [ Cavernous Sinus ] [ Orbit ] [ Parotid Region, TMJ, Mandible ] [ Infratemporal Fossa ] [ Pterygopalatine Fossa ]

Boundaries

  1. anterior: inferior orbital fissure
  2. posterior: foramen rotundum and pterygoid canal
  3. superior: body of sphenoid bone
  4. inferior: pharyngeal canal, greater and lesser palatine canals
  5. medial: sphenopalatine foramen, perpendicular plate of palatine bone, medial pterygoid plate
  6. lateral: pterygomaxillary fissure

Related Bony Landmarks

  1. sphenoid sinus - bisected skull, posterior to pterygopalatine fossa
  2. pterygoid canal - floor of sphenoid sinus, vidian nerve (nerve of pterygoid canal)
  3. posterior nasal aperature (piriform aperture) - anterior boundary of nasopharynx
  4. pharyngeal tubercle of occipital bone - attachment of buccopharyngeal fascia, region of distribution of pharyngeal nerve
  5. region of soft palate - between the hamuli of the medial pterygoid plates, region of distribution for lesser palatine nerve
  6. inferior opening of lesser palatine canal
  7. hard palate - horizontal plate of palatine bone - distribution of greater palatine nerve
  8. inferior opening of greater palatine canal
  9. incisive foramen - transmits terminal branches of nasopalatine nerves from nasal cavity to anterior hard palate
  10. superior, middle, and inferior, nasal conchea - region of distribution for lateral posterior nasal nerves
  11. nasal septum - perpendicular plate of ethmoid bone and the vomer, region of distribution for nasopalatine nerve
  12. sphenopalatine foramen - viewed from lateral nasal wall, transmits lateral posterior nasal nerves and nasopalatine nerve
  13. foramen on posterior aspect maxilla for posterior superior alveolar nerve

Contents

  1. maxillary nerve - enters lateral roof of pterygopalatine fossa via foramen rotundum, leaves via inferior orbital fissure as infraorbital nerve
  2. vidian nerve (nerve of pterygoid canal) - continuation of GSPN and deep petrosal nn., enters pterygopalatine ganglion
  3. pterygopalatine ganglion - site of postganglionic parasympathetic cell bodies
  4. motor root of pterygopalatine ganglion - carries GVE postganglionic fibers to maxillary nerve
  5. sensory root of pterygopalainte ganglion - branch of maxillary nerve
  6. pharyngeal nerve - through pharyngeal canal to nasopharynx
  7. lesser palatine nerve - through lesser palatine canal to soft palate
  8. greater palatine nerve - through greater palatine canal to hard palate
  9. superior, middle, and inferior lateral posterior nasal nerves - to the turbinates, through sphenopalatine foramen
  10. nasopalatine nerve - to the nasal septum, through sphenopalatine foramen
  11. posterior superior alveolar nerve - to the maxillary sinus, through pterygomaxillary fissure to foramen on posterior maxilla
  12. zygomatic nerve - enters orbit through inferior orbital fissure, carries GVE to zygomaticotemporal nerve (to lacrimal n. to lacrimal g.)
  13. maxillary artery and terminal branches
  14. artery of maxillary nerve - not easily demonstrated
  15. artery of pterygoid canal - not easily demonstrated
  16. pharyngeal artery
  17. greater and lesser palatine arteries
  18. lateral posterior nasal arteries
  19. posterior septal artery
  20. infraorbital artery (may not enter pterygopalatine fossa)
  21. posterior superior alveolar artery - usually not in pterygopalatine fossa as is the nerve

Comments

Each of the branches of the maxillary nerve provide a trigeminal pathway followed by postganglionic parasympathetic fibers (GVE) from the pterygopalatine ganglion. Additionally, GVE postganlionic sympathetic fibers derived from the deep petrosal nerve follow each of these same pathways. Parasympathetic GVE fibers control mucosal secretions of the oral/nasal cavity, sphenoid sinus, maxillary sinus, ethmoidal air cells, and secretions of the lacrimal gland. Sympathetic GVE fibers control vasoconstriction to these same regions. Additionally, taste fibers (SVA) derived from the greater superficial petrosal nerve (facial nerve) follow the greater and lesser palatine nerves to the hard and soft palate. GVA fibers from the greater superifical petrosal nerve are thought to follow the lesser palatine nerve to the soft palate. This last distribution is often questioned.