Overview
This lecture covers the anatomy of the pterygopalatine fossa, its boundaries, the foramina connecting it to other skull regions, and the key nerves and vessels passing through it.
Boundaries and Location of the Pterygopalatine Fossa
- Pterygopalatine fossa is a small, inverted pyramid-shaped space deep in the face.
- Anterior wall: posterior aspect of the maxilla.
- Posterior wall: pterygoid process of the sphenoid bone.
- Medial wall: perpendicular plate of the palatine bone.
- Lateral boundary: pterygomaxillary fissure opens into the infratemporal fossa.
- Roof: formed by the greater wing of the sphenoid bone.
- Floor: pyramidal process of the palatine bone.
Important Openings and Connections
- Inferior orbital fissure connects the fossa to the orbit.
- Foramen rotundum transmits the maxillary nerve (V2) from the middle cranial fossa.
- Vidian (pterygoid) canal (contains the nerve of the pterygoid canal).
- Palatovaginal (pharyngeal) canal connects to the nasopharynx.
- Greater and lesser palatine foramina lead to the oral cavity.
- Sphenopalatine foramen connects the fossa to the nasal cavity.
Arterial Supply
- Main artery: maxillary artery (branch of the external carotid artery) enters the fossa.
- Branches:
- Infraorbital artery (via inferior orbital fissure; gives anterior and middle superior alveolar arteries).
- Posterior superior alveolar artery.
- Descending palatine artery (branches: greater and lesser palatine arteries).
- Sphenopalatine artery (supplies nasal cavity).
- Artery of the pterygoid canal.
Nerve Supply
- Maxillary nerve (V2, from trigeminal) enters through foramen rotundum.
- Branches:
- Infraorbital nerve (gives anterior, middle, posterior superior alveolar nerves).
- Greater and lesser palatine nerves.
- Nasopalatine nerve (through sphenopalatine foramen).
- Zygomatic nerve.
- Pharyngeal branch (through palatovaginal canal).
- Pterygopalatine ganglion located in the fossa.
- Parasympathetic fibers (from facial nerve via greater petrosal nerve) and sympathetic fibers (from deep petrosal nerve) join to form the vidian nerve.
- Vidian nerve synapses at the pterygopalatine ganglion; postganglionic fibers supply lacrimal gland and other facial regions.
Key Terms & Definitions
- Pterygopalatine fossa — Deep facial space bordered by maxilla, sphenoid, and palatine bones.
- Foramen rotundum — Opening for maxillary nerve V2 to enter the fossa.
- Pterygomaxillary fissure — Lateral opening to the infratemporal fossa.
- Sphenopalatine foramen — Medial opening to the nasal cavity.
- Pterygopalatine ganglion — Parasympathetic ganglion in the fossa.
- Vidian canal — Canal for the nerve of the pterygoid canal (vidian nerve).
Action Items / Next Steps
- Review diagrams and CT images of the pterygopalatine fossa and its boundaries.
- Test your knowledge with the provided question bank on head, neck, and neuroanatomy.