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Infratemporal Fossa Part II

Deep Contents of the infratemporal fossa Muscles: tensor palati and levator palati. Nerve: Maxillary nerve and it branches. Autonomic ganglion: Spheno-palatine ganglion. Arteries: 3rd part of maxillary artery and its branches (mentioned before).

Tensor Palati Origin: 1. Spine of sphenoid 2. Scaphoid fossa 3. Outer wall of auditory tube Insertion: Palatine aponeurosis (the tendon hooks on the pterygoid hamulus). Nerve supply: Nerve to medial pterygoid from main trunk of mandibular nerve. Action: It tenses the soft palate.

Levator Palati Origin: 1. Inferior surface of the petrous part of the temporal bone. 2. Lower surface of auditory tube Insertion: Palatine aponeurosis. Nerve supply: Pharyngeal plexus (cranial part of accessory nerve). Action: It elevates the soft palate.

Maxillary nerve One of the divisions of the trigeminal nerve It is a pure sensory nerve. It passes in the lateral wall of the cavernous sinus. Then leaves the skull through foramen rotundum to enter the pterygopalatine fossa. It curves laterally through the pterygomaxillary fissure to lie deep in the infratemporal fossa. Through the inferior orbital fissure, it enters the floor of the orbit and continues as infraorbital nerve, which runs in the infraorbital groove, canal then foramen and terminates in the face.

Branches From of maxillary nerve: Meningeal branch: supplies the dura of the middle cranial fossa. Two ganglionic branches: which hang the sphenopalatine ganglion, they contain sensory fibers coming from nose, palate and pharynx and postganglionic fibers going to the lacrimal gland. Zygomatic branch: arises in the pterygopalatine fossa and enters the orbit through the inferior orbital fissure. It divides into zygomatico-temporal and zygomatico-facial branches that supply skin of the face.

Branches Posterior superior alveolar nerve: arises in the pterygopalatine fossa and pierces the posterior surface of the maxilla to supply the maxillary sinus, the upper molar teeth and adjoining parts of the gum and cheek. From of infraorbital nerve: Middle superior alveolar nerve: arises in the infraorbital groove and descends on the lateral wall of the maxillary sinus to supply the upper premolar teeth and adjoining parts of the gum and cheek.

Branches Anterior superior alveolar nerve: arises in the infraorbital canal and descends on the anterior wall of the maxillary sinus to supply the upper canine and incisor teeth and adjoining parts of the gum and a small part of the lateral wall and floor of the nasal cavity Terminal Branches in the face: after its exit through the infraorbital foramen it divides into palpebral, nasal and labial branches which supply skin of the face.

Sphenopalatine ganglion A parasympathetic ganglion which lies in the pterygopalatine fossa, hanged by two roots from the maxillary nerve. Roots: Preganglionic Parasympathetic root: from the lacrimal nucleus (in the brain stem), to the facial nerve which gives the greater petrosal nerve which enters the pterygoid canal, unites with the deep petrosal nerve to form the nerve of pterygoid canal which joins the ganglion from its posterior aspect where they relay inside the ganglion and gives postganglionic branches. Postganglionic Sympathetic root: from the deep petrosal nerve which is a branch from the internal carotid nerve in the foramen lacerum (the sympathetic plexus around the internal carotid artery from the upper deep cervical sympathetic ganglion). The deep petrosal nerve unites with the greater petrosal nerve to form the nerve of pterygoid canal (vedian nerve). Two Sensory roots: from the maxillary nerve.

Sphenopalatine ganglion Secretomotor Branches: To the lacrimal gland: through the maxillary nerve  zygomatic branch  zygomatico-temporal branch  communicates with the lacrimal nerve  the lacrimal gland. To the mucous glands of the nose, palate. Sensory Branches from the maxillary nerve to the nose, palate, pharynx and orbit : Orbital branches: through the inferior orbital fissure. Greater and lesser palatine nerves. Nasal branches. Pharyngeal branches.

Pterygopalatine fossa Boundaries: Anterior: posterior surface of maxilla. Posterior: pterygoid process. Medial: perpendicular plate of palatine bone. Lateral: infratemporal fossa (through pterygomaxillary fissure). Contents: Maxillary nerve and branches. Sphenopalatine ganglion and branches. 3rd part of maxillary artery and branches.

Pterygopalatine fossa Communications: Ptergomaxillary fissure  infratemporal fossa. Foramen rotundum  middle cranial fossa. Sphenopalatine foramen  nasal cavity. Inferior orbital fissure  orbital cavity. Greater palatine canal  palate. Palatinovaginal canal  nasopharynx. Pterygoid canal  foramen lacerum.

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