THE PTERYGOPALATINE FOSSA

1. THE PTERYGOPALATINE FOSSA

2. Pterygopalatine fossa Pyramidal space inferior to the apex of the orbit. Lies between pterygoid process of the sphenoid posteriorly and the posterior aspect of the maxilla anteriorly. Medially: perpendicular plate of the palatine bone, part of the lat. Wall of the nose. Roof: body of the sphenoid Floor the pyramidal process f the palatine bone. Sup. End opened into inf orbital fissure. Inf end is closed except for the palatine foramina.

3. Pterygopalatine fossa Communications: Laterally with the infratemporal fossa through the pterygomaxillary fissure. Medially with the nasal cavity through the sphenopalatine foramen. Anterosuperiorly with the orbit through the inferior orbital fissure. Posterosuperiorly with the middle cranail fossa through foramen rotundum and pterygoid canal. With palate: through greater & lesser palatine canals & foramina. With pharynx: through pterygoid canal & palatovaginal canal.

4. Pterygopalatine fossa Contents: Terminal (third or pterygoid: part of the maxillary a. and the initial parts of its branches. Maxillary v. Maxillary nerve. Pterygopalatine ganglion.

5. Maxillary artery Terminal; branch of the external carotid a. Traverses infratemporal fossa, passes lateal pterygoid m. enters the Pterygopalatine fossa through the pterygomaxillary fissure. Within Pterygopalatine fossa lies ant to pterygopalatine ganglion.

6. Maxillary artery Branches: Posterior sup. Alveolar a. Descending palatine a. divides into greater and lesser palatine a. Artery of the pterygoid canal. Sphenopalatine a., which divides into posterior lateral nasal branches to the lat. Wall of the nasal cavity and its associated paranasa; sinuses and the post. Septal branches. Infraorbital a. which gives rise to the ant. Sup. Alveolar a. and terminates as branches to the eye liod, nose, and upper lip.

7. Maxillary nerve Meningeal branch to the front of the middle cranial fossa. Enters pterygopalatine fossa through foramen rotundum. Runs anterolatrally in the fossa. Within the fossa gives rise to: 1. Zygomatic n. Which divides into zygomaticifascial and zygomaticotemporal ns. And supply general sensation to the lat. Region of the cheek and temple. A communicating br. From the zygomaticotemporal n. which convey parasympathetic secretomotor fibers to the lacrimal gland by way of lacrinal n. from CN V1.

8. Maxillary nerve 2. two pterygopalatine nerves that suspend the parasympathetic pterygopalatine ganglion in the sup part of the pterygopalatine fossa. They convey general sensory fibers of the maxillary n which pass through the ganglion without synapsing and supply the nose, palate, tonsil and gingiva.

9. Maxillary nerve Maxillary nerve leaves the fossa through the inf. orbital fissure after which it is known as infraorbital n.

10. Maxillary nerve Parasympathetic fibers to the ganglion come from the fascial n. by way of greater petrosal n.(ist br.) greater petrosal n. joins deep petrosal n. as it passes through foramen lacerum to form nerve of the pterygoid canal (vidian n.), which pass through this canal to the pterygopalatine fossa. The parasympathetic fibers of the greatwer petrosal n. synapse in the pterygopalatine ganglion.

11. Maxillary nerve The deep petrosal n. is a sympathetic n. from internal carotid plexus. Post ganglionic fibers are nerve cell bodies in the sup. Cervical ganglion

12. Nose Part of respiratory tract. Sup to hard palate. Contains peripheral organ of smell.nasal septum divide nose into Rt and Lt nasal cavities. Each cavity is divided into an olfactory area and respiratory area.

13. Nose Function of the nose and nasal cavity: Olfaction. Respiration. Filteration of dust. Humidification of inspired air. Reception of secretion from paranasal cavities and nasolacrimal duct.

14. External Nose Project from the face. Cartilagenouis skeleton. Vary in size and shape because of difference in nasal cartilages. Extend from its sup angle or root to the apex of the nose. Inferior surface pierced by nares (nostrils, ant. Nasal apertures), which are bounded laterally by alae of the nose and separated from each other by the skin overlying the nasal septum..

15. External Nose Sup bony part and root are covered by thin skin, but in cartilagenous part is thicker skin containing many sebaceous glands. Skin extend to vestibule of nose. Vestibule contains vibrissae (stiff hairs). Junction between skin and mm. is beyond hair bearing area.

16. Skeleton of the external nose Composed of bone and hyaline cartilage. Bony part: Nasal bones Frontal process of maxilla Nasal part of the frontal bone and its nasal spine

17. Skeleton of the external nose Nasal septum has a hard bony part and soft mobile part. Cartilagenous part of nose are five in no.: Two lat. Two alar. Septal.

18. Nasal septum Main components: Perpendicular plate of ethmoid forming sup part of ethmoid extended from cribriform plate and superior to this plate as crista gali. Vomer form posteroinf part of nasal septum Septal cartilage articulate with bony edge of the septum.

19. Nasal cavity Anteriorly nares, posteriorly choanae. Nasal cavity is lined with mm. except vestibule which lined by vibrissae. Mm. continue with all the nasal cavities that is connected: nasopharynx posteriorly Paranasal sinuses superiorly and laterally Lacrimal sac and conjunctiva superiorly. M m. inf 2/3 is respiratory, sup 1/3 is olfactory.

20. Nasal cavity Boundaries: Roof: curved and narrow except at post end, roof is divided into three parts (frontonasal, ethmoidal, and sphenoidal).

21. Nasal cavity Floor: wider, palatine process of maxilla and horizontal platye of palatine bone. Medial wall: nasal septum Lateral wall: three nasal chonchae, each forming a roof for the groove or meatus.

22. Nasal cavity Nasal conchae are sup, middle and inf.divide nasal cavity into 4 passages: Sphenoethmoidal recess. Lie superopost to sup meatus, receive opening of sphenoidal sinus. Sup meatus. Post ethmoidal sinus opens into it by one or more orifices.

23. Nasal cavity Middle meatus. Wider, anterosup part of it leads to ethmoidal infundibulum through which communicates with frontal sinus by frontonasal duct. Frontal sinus opens into hiatus semilunaris. Ethmoidal bulla formrd by middle ethmoidal cells that form the ethmoidal sinus. Maxillary sinus also opens into the post end of the semilunar hiatus

24. Nasal cavity Inferior meatus, covered by mm. contain large vascular spaces, can enlarge. During infection the mm enlarge and may block the nose. Nasolacrimal duct opens into it.

25. Blood supply Medial and lat nasal cavity is supplied by branches of: Sphenopalatine a. Ant and post ethmoidal a. Greater palatine a. Sup labial a and lat nasal branchesfascial a.

26. Blood supply Kiesselbach’s area where all the five arteries suppliant the septum anastomose lie on the ant part of the nasal septum where profuse bleeding from nose occurs.

27. Venous drainage Rich plexus of veins deep to nasal mucosa drains into sphenopalatine, fascial and ophthalmic veins. thermoregulator

28. Nerve supply The olfactory area of the roof, and upper parts of the lateral walls and septum are supplied by the olfactory n. Vestibular area by infraorbital n. respiratory area of the lateral wall supplied at the front by the ant ethmoidal n in the upper part, and in the lower part by filaments from the ant sup alveolar n, at the upper back part by the lateral post sup nasal branches from pterygopalatine ganglion through the sphenopalatine foramen, at the lower back part by the post inf nasal branchesof the greater platine n

29. Nerve supply Upper part of the nasal septum olfactory in the upper part. ant ethmoidal at the front. Medial post sup nasal including the nasaopalatine at the back.

30. Paranasal sinuses Are air filled extensions of the respiratory part into the following cranial bones: frontal, ethmoidal, sphenoidal and maxillary.

31. Frontal sinus Between the inner and outer table of the frontal bone. Post to the superciliary arches and the root of te nose. Usually detectable in children by 7 years of age. Each sinus drains through the frontonasal duct into the infundibulum, which opens into the semilunar hiatus of the middle meatus. Supplied byb branches of the supraorbital nerves.

32. Ethmoidal sinus Comprise several cavities- ethmoidal cells. Between nasal cavity and orbit Not visible by radiograph before 2 years. Ant ethmoidal cells drains directly or indirectly into the middle meatus through the infundibulum. Middle ethmoidal cells open directly into the middle meatus. The post, ethmoidal cells open directly in to sup meatus. Supplied by the ant and post ethmoidal ns from the nasociliary n

33. Sphenoidal sinus Lie in the body of the saphenoid. Thin plate of bone separate the sinus from Optic n and optic chiasma, pitutary glanh, internal carotid arteriesveins., and the cavernous sinuses. Open into sphenoethmoidal recess The post ethmoidal arteries and post ethmoidal

34. Maxillary sinus Apex extend toward the zygomatic bone. Base at the lat wall of the nose the roof is formed by the floor of the orbit. Floor formed by the alveolar part of the maxilla. Each maxillary sinus drains by an opening – the maxillary ostium into the middle meatus at the post part of the ifundibulum.

35. Maxillary sinus Arterial supply mainly from sup alveolar branches of the maxillary a. floor of the sinus by the branches of the greater palatine arteries. NS: from the ant. Middle, and post sup alveolar nerves br from the maxillary.