Regional Anatomy II Week 5 SU22 PDF

Week 5 Temporal, infratemporal, pterygopalatine fossae Temporal Fossa Temporal Fossa Contents: • Temporalis muscle and its fascia • Deep temporal nerves and vessels • Superficial temporal vessels • Auriculotemporal nerve • Zygomaticotemporal nerve and vessels Temporal Fossa Boundaries: • Ante...

Week 5 Temporal, infratemporal, pterygopalatine fossae Temporal Fossa Temporal Fossa Contents: • Temporalis muscle and its fascia • Deep temporal nerves and vessels • Superficial temporal vessels • Auriculotemporal nerve • Zygomaticotemporal nerve and vessels Temporal Fossa Boundaries: • Anterior: zygomatic process of frontal bone and frontal process of zygomatic bone • Superior and posterior: superior temporal line • Inferior: zygomatic arch • Floor: composed of portions of parietal, frontal, greater wing of sphenoid, and squamous part of temporal area. Where the four bones approach each other is known as pterion. It overlies anterior branch of middle meningeal artery. (laceration of this artery is the most common cause of epidural hematomas) Contents include: Temporalis muscle, fascia, deep temporal artery and vein Infratemporal Fossa Infratemporal Fossa Boundaries: ● ● ● ● ● Anterior: infratemporal (posterior) surface of body of maxilla Posterior: tympanic part of styloid process of temporal bone Medial: lateral pterygoid plate Lateral: ramus of mandible Superior: infratemporal surface of greater wing of sphenoid Superficial view Deep view Deep view Infratemporal Fossa Communications: ● ● ● ● Temporal fossa via space between zygomatic arch and cranial wall Orbit via inferior orbital fissure Middle cranial fossa via foramen ovale and foramen spinosum Pterygopalatine fossa via pterygomaxillary fissure Infratemporal Fossa Contents: ● ● ● ● ● ● ● Lower part of temporalis muscle Medial and lateral pterygoid muscles Mandibular nerve (V3) and its branches Chorda tympani Otic ganglion Maxillary artery and its branches Pterygoid venous plexus and maxillary vein Mandibular Nerve ● ● ● ● ● A.k.a. V3 Contains general sensory, motor, and autonomic fibers Leaves middle cranial fossa and enters infratemporal fossa via foramen ovale In infratemporal fossa, lies deep to lateral pterygoid branches into anterior and posterior divisions Branches from main trunk (stem) ○ ○ Medial pterygoid nerve supplies medial pterygoid muscle and gives small branches to tensor tympani and tensor veli palatini Meningeal branch (nervus spinosus): enters cranial cavity through foramen spinosum and supplies dura mater of middle cranial fossa Mandibular Nerve Branches from anterior division: innervate the muscles of mastication ● ● ● ● Masseteric nerve - passes through mandibular notch to reach masseter, which is supplies. It also contains a few sensory fibers for anterior aspect of temporomandibular joint Lateral pterygoid nerve - supplies lateral pterygoid Deep temporal nerves (anterior and posterior) - ascend deep to temporalis muscle to supply it Buccal nerve - passes between two heads of lateral pterygoid and runs anterior and inferior to emerge onto cheek to provide sensory innervation to skin and mucosa of the cheek Mandibular Nerve Branches from posterior division: ● Auriculotemporal nerve ○ ○ ○ ○ Originates by two roots that encircle middle meningeal artery and join posterior to it Passes superficial temporal vessels Gives sensory innervation to auricle, external acoustic meatus, tympanic membrane, TMJ, and scalp Gives off parotid branches - gives postganglionic parasympathetic fibers from otic ganglion Mandibular Nerve Branches from posterior division: ● Inferior alveolar nerve ○ ○ ○ ○ Contains motor and sensory fibers Supplies sensory innervation to all mandibular teeth of corresponding side Gives off mental nerve, which emerges onto face via mental foramen and supplies sensory innervation to lower lip and chin Before entering mandibular canal, it gives off mylohyoid nerve and supplies mylohyoid and anterior belly of digastric Mandibular Nerve Branches from posterior division: ● Lingual nerve ○ ○ Gives general sensory innervation (touch, pain, temperature) to mucosa of anterior ⅔ of tongue and mucosa of floor of mouth High in infratemporal fossa is joined by chorda tympani Chorda Tympani ● ● ● Originates from facial nerve within facial canal, just above styloid foramen, and enters tympanic cavity and passses anterior across medial surface of tympanic membrane. Exits temporal bone via petrotympanic (Glaserian) fissure in infratemporal fossa to join the lingual nerve Contains special sensory fibers (taste) for anterior ⅔ of tongue and preganglionic parasympathetic fibers Preganglionic parasympathetic fibers terminate in submandibular ganglion which innervate the submandibular and sublingual salivary glands Otic Ganglion ● ● ● Small parasympathetic ganglion located in infratemporal fossa, inferior to foramen ovale and medial to mandibular nerve Receives preganglionic parasympathetic fibers from glossopharyngeal nerve via lesser petrosal nerve Postganglionic parasympathetic fibers leave otic ganglion and join auriculotemporal nerve, traveling together to reach the parotid gland Maxillary Artery in Infratemporal Fossa ● ● Larger terminal branch of external carotid artery Passes anterior, deep to neck of mandible, runs through infratemporal fossa and terminates in pterygopalatine fossa Parts: 1. 2. 3. Mandibular (1st) Pterygoid (2nd) Pterygopalatine (3rd) Maxillary Artery Branches of mandibular (1st) part: 1. Deep auricular artery - supplies external acoustic meatus and outer surface of tympanic membrane 2. Anterior tympanic artery - enters tympanic cavity via petrotympanic fissure (with chorda tympani) to supplies mucosa of tympanic cavity 3. Middle meningeal artery - passes between two roots of auriculotemporal nerve to enter middle cranial fossa via foramen spinosum. The main artery and its branches lie between bone and dura mater to supply the dura mater and bones of skull Maxillary Artery Branches of mandibular (1st) part (cont.): 4. Accessory meningeal artery - enters cranial cavity via foramen ovale to supply trigeminal ganglion and adjacent dura mater. 5. Inferior alveolar artery - accompanies inferior alveolar nerve & enters mandibular canal via mandibular foramen. Within mandibular canal, gives branches to lower teeth and gingiva and gives off mental artery (exits through mental foramen with corresponding nerve). Before entering mandibular canal, it gives off mylohyoid artery (accompanies mylohyoid nerve). Maxillary Artery Pterygoid (2nd) part: Circulation to the muscles of mastication Branches (all accompany branches of mandibular nerve): 1. Masseteric artery - passes through mandibular notch to supply masseter muscle. 2. Deep temporal arteries (anterior and posterior) - ascend deep to temporalis muscle to supply it 3. Pterygoid arteries - supply medial and lateral pterygoid muscles 4. Buccal artery - runs anterior and inferior toward buccinator muscle; supplies buccinator, skin, mucosa of cheek Maxillary Artery Summary of maxillary artery distribution in the infratemporal fossa: ● ● ● ● Tympanic region Muscles of mastication Meninges Lower teeth Pterygoid Venous Plexus ● ● ● ● ● ● Complex venous network located in infratemporal fossa Receives veins which correspond with branches of maxillary artery Drained posteriorly by maxillary vein, enters the parotid gland, which joins superficial temporal vein within the parotid gland, to form retromandibular vein. Communicates with cavernous sinus via emissary veins passing through various foramina (ovale, lacerum) Communicates with inferior ophthalmic vein via veins passing through inferior orbital fissure Communicates with facial vein via deep facial vein Pterygopalatine Fossa Pterygopalatine Fossa Small pyramidal space located medial to infratemporal fossa Boundaries: ● ● ● ● Anterior - posterior surface of body of maxilla Posterior - pterygoid process Superior - greater wing of sphenoid Medial - perpendicular plate of palatine Communications/nerve branches: ● ● ● with infratemporal fossa via pterygomaxillary fissure with orbit via inferior orbital fissure with middle cranial fossa via foramen rotundum Pterygopalatine Fossa Communications (cont.): ● ● ● With nasal cavity via sphenopalatine foramen Pterygoid canal - runs through upper part of medial pterygoid Greater and lesser palatine canals - begin at inferior end of pterygopalatine fossa and terminates on inferior aspect of hard palate Pterygopalatine Fossa Contents: 1. 2. 3. Maxillary nerve Pterygopalatine (3rd) part of maxillary artery Pterygopalatine ganglion Contents: Maxillary Nerve ● ● ● Contains only general sensory fibers Leaves middle cranial fossa and enters pterygopalatine fossa via foramen rotundum; passes anterior through upper part of pterygopalatine fossa and enters the orbit via inferior orbital fissure where it becomes the infraorbital nerve. Infraorbital nerve lies in infraorbital groove and then in infraorbital canal, and emerges onto face through infraorbital foramen. Maxillary Nerve ● ● Only sensory Intracranial branch: ○ ● Meningeal branch - supplies dura mater of middle cranial fossa Extracranial branches in pterygopalatine fossa: ○ ○ Ganglionic branches - connect maxillary nerve with pterygopalatine ganglion (parasympathetic ganglion located in pterygopalatine fossa, inferior to maxillary nerve) The ganglionic branches contain mostly sensory fibers (also contain a few postganglionic parasympathetic fibers for lacrimal gland) Zygomatic nerve - enters orbit via inferior orbital fissure & runs anterior, along lateral wall of orbit, and divides into zygomaticofacial and zygomaticotemporal nerves Maxillary Nerve Branches in pterygopalatine fossa (cont.): Zygomatic nerve (expanded): ● ● ● Zygomaticofacial nerve - supplies skin over prominence of cheek Zygomaticotemporal nerve - supplies skin over anterior temporal region Posterior superior alveolar nerve - supplies maxillary molar teeth and mucosa of maxillary sinus Maxillary Nerve Branches from infraorbital part: ● ● Middle superior alveolar nerve supplies maxillary premolar teeth and mucosa of maxillary sinus Anterior superior alveolar nerve supplies maxillary incisors and canine and mucosa of maxillary sinus Branches in face: ● Infraorbital nerve emerges onto face via infraorbital foramen and divides into branches that supply skin and conjunctiva of lower eyelid, skin of side of nose, and skin and mucosa of upper lip; middle third of the face. Contents: Pterygopalatine Ganglion ● ● ● ● ● ● Parasympathetic ganglion located in pterygopalatine fossa, inferior to maxillary nerve Receives three types of fibers (sensory, preganglionic parasympathetic and postganglionic sympathetic), but only preganglionic parasympathetic fibers synapse in ganglion Branches that originate or leave from pterygopalatine ganglion contain sensory, postganglionic parasympathetic and/or postganglionic sympathetic fibers Source of general sensory fibers: maxillary nerve/V2 Source of preganglionic parasympathetic fibers - greater petrosal nerve originating from the facial nerve Source of postganglionic sympathetic fibers - deep petrosal nerve originating from superior cervical sympathetic ganglion. Postganglionic parasympathetic fibers arise from facial nerve and innervate the mucosal glands of the nasal cavity, the palate, and lacrimal gland Parasympathetic postganglionic leave the pterygopalatine ganglion, and jump onto the lacrimal nerve from V1 to get to lacrimal gland Greater and lesser palatine nerve pass through their respective foramen to innervate the palate Pterygopalatine Ganglion Greater petrosal nerve: ● ● ● ● Branch of facial nerve Contains preganglionic parasympathetic fibers for lacrimal gland and glands of nasal cavity, palate and nasopharynx Joins deep petrosal nerve (branch of internal carotid plexus). It contains postganglionic sympathetic fibers (from neurons located in superior cervical ganglion of sympathetic trunk) The greater and deep petrosal nerves join to form nerve of pterygoid canal Pterygopalatine Ganglion Nerve of pterygoid canal passes through pterygoid canal, and terminates in pterygopalatine ganglion ● ● Preganglionic parasympathetic fibers synapse in pterygopalatine ganglion Sensory and postganglionic sympathetic fibers do not synapse in ganglion but pass without interruption into branches Pterygopalatine Ganglion Branches: 1. 2. 3. Greater palatine nerve - emerges on inferior surface of hard palate via greater palatine foramen and runs anterior on inferior surface of hard palate to supply mucosa of posterior part of hard palate Lesser palatine nerve - emerges on inferior surface of hard palate via lesser palatine foramen to supply the mucosa of soft palate and tonsil Nasopalatine (long sphenopalatine) nerve - enters nasal cavity via sphenopalatine foramen and passes through incisive canal and emerges on inferior surface of hard palate via incisive fossa to supply mucosa of anterior part of hard palate (behind incisors) Pterygopalatine Ganglion Branches: 4. Posterolateral nasal branches - originate from pterygopalatine ganglion and greater palatine nerve to supply mucosa of posterior part of lateral wall of nasal cavity 5. Pharyngeal nerve - supplies mucosa of sphenoidal sinus and nasopharynx 6. Path of postganglionic parasympathetic fibers for lacrimal gland pterygopalatine ganglion, maxillary nerve, zygomatic nerve, zygomaticotemporal nerve, communicating branch with lacrimal nerve, and lacrimal gland Contents: Maxillary Artery ● ● Maxillary artery leaves infratemporal fossa and enters pterygopalatine fossa via pterygomaxillary fissure Its branches follow branches of maxillary nerve and pterygopalatine ganglion Branches: 1. Posterior superior alveolar artery - accompanies posterior superior alveolar nerve and descends on posterior surface of maxilla. It divides into branches which pass through alveolar foramen of maxilla, supplies maxillary molar and premolar teeth and mucosa of maxillary sinus Pterygopalatine Part of Maxillary Artery Branches (cont.): 2. Infraorbital artery - accompanies infraorbital nerve to enter the orbit through inferior orbital fissure to run anteriorly in infraorbital groove and infraorbital canal. It emerges onto face via infraorbital foramen to give the following branches • Anterior superior alveolar artery that supplies maxillary incisor and canine teeth and mucosa of maxillary sinus (sometimes there is also a middle superior alveolar artery. • Terminal branches (on face) supply lower eyelid, side of nose and upper lip Pterygopalatine Part of Maxillary Artery Branches (cont.): 3. Descending palatine artery - divides into lesser and greater palatine arteries that pass through incisive canal and anastomoses with a branch of sphenopalatine artery pharyngeal artery to supply mucosa of nasopharynx and sphenoidal sinus 4. Artery of pterygoid canal - supplies walls and contents of pterygoid canal and mucosa of nasopharynx, auditory tube and tympanic cavity Pterygopalatine Part of Maxillary Artery Branches (cont.): 5. Sphenopalatine artery - terminal branch of maxillary artery enters the nasal cavity via sphenopalatine foramen to give off posterolateral nasal branches and posterior septal branches 6. Posterior septal branches - supply mucosa of posterior part of nasal septum. One of these branches anastomoses with a branch of greater palatine artery