Nasal Cavity Anatomy


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Nasal Cavity Anatomy

  1. 1. Nasal cavityNasal cavity • Extends from nares as far back asExtends from nares as far back as posterior nasal apertures or CHOANAE.posterior nasal apertures or CHOANAE. • Between posterior border of medialBetween posterior border of medial pterygoid plates of spehnoid n vomer.pterygoid plates of spehnoid n vomer. • Here nasal cavity communicates withHere nasal cavity communicates with nasopharynx.nasopharynx.
  2. 2. Lateral wallLateral wall • Mainly formed by maxilla.Mainly formed by maxilla. • Perpendicular plate of palatine bone does soPerpendicular plate of palatine bone does so posteriorly n beyond this medial pterygoid plateposteriorly n beyond this medial pterygoid plate with which articulates.with which articulates. • Extends as far back as choanae.Extends as far back as choanae. • Sphenopalatine foramen present at the top ofSphenopalatine foramen present at the top of perpendicular plate .perpendicular plate . • Provides a portal for communication betweenProvides a portal for communication between nasal cavity n pterygopalatine fossa.nasal cavity n pterygopalatine fossa.
  3. 3. The labyrinth • Lateral mass) of ethmoid bone. • Occupies much of upper part of maxillary hiatus. • The inferior concha lies below it. • Articulating anteriorly with maxilla n post: with palatine bone. • Superior n middle conchae are part of ethmoidal labyrinth. • These conchae called also as turbinates=are curved shelves of bone projects into nasal cavity from their attachments on lateral wall.
  4. 4. • Each enloses a passage the Meatus under its concave inferior surface. • The Atrium= A depression in front of middle concha,leads upwards into meatus behind it. • Atrium bounded anterioly n above by ridge=THE AGAR NASI. • This may contain few ethmoidal air cells.
  5. 5. Anteriosuperior part of lateral wall • Formed by nasal bone n frontal process of maxilla. • Lacrimal bone articulate with later n with inferior concha. • Enclosing between them canal for nasolacrimal duct. • Opens into upper part of inferior meatus about 1cm behind anterior end of concha.
  6. 6. Medial wall or nasal septum. • Consist of bone and cartilage. • The traingular vomer,articulating above with sphenoid body . • Forms posterior border of septum. • Inferiorly it is slotted into a grooved ridge on hard palate n extends beyond incisive canal. • Vomer is grooved on each side by nasopalatine nerves. • Perpendicular plate of ethmoid articulates with upper margin of vomer but not whole length.
  7. 7. Septal cartilage • Unossified part of ethmoid’s perpendicular plate forms anterosuperior part of septum. • Inferiorly slotted into a bony groove at its vomerine n amxillary articlulations. • Anteriorinferior corner of septum is mobile. • Formed by medial crura of paired major alar cartilages.
  8. 8. THE FLOOR • Upper surface of hard palate. • Which forms roof of mouth n comprises the palatal process of maxilla n horizontal plate of palatine bone. • Either side of septum anteriorly a small opening leads to an incisive canal traversed by nasopalatine nerve n greater palatine artery. • Central part of roof is cribriform plate of the ethmoid.
  9. 9. Face Bones (Cont.)Face Bones (Cont.) • Inferior Nasal Conchae (2)Inferior Nasal Conchae (2) – Located on each side ofLocated on each side of the nasal septumthe nasal septum – Create turbulence in theCreate turbulence in the inspired airinspired air • To increase epithelialTo increase epithelial surface areasurface area • To warm and humidifyTo warm and humidify inhaled airinhaled air
  10. 10. Nasal spine of the frontal bone n nasal bones. • Present in front sloping downwards. • At the back is sloping anterior aspect of sphenoid body. • The surface marking of cribriform plate is horizontal plane on which pupils lie as eyes gase directly forwards. • Skin of external nose is reflected around naris to line vestibule. • That Part of nasal caity bounded by the ala.
  11. 11. • Skin here bears stiff hairs. • The mucocutaneous junction is marked by a cresentic infolding,limen nasi. • This coincide with upper margin of major alar cartilage. • Mucous membrane lining the roof n upper part of septum n laterall wall is OLFACTORY EPTITHELIUM. • Mucous secretion traps particulate matter n ciliary action wafts the mucous film back into nasopharynx.
  12. 12. Watery secretion of serous glands • Evaporates to moisten the inspired air. • Mucous membrane is very vascular with large venous sinusoids and arteriovenous shunts. • Especially over inferior concha n this helps to warm the inspired air. • Mecous membrane of nose is adherent to underlying periosteum or perichondrium of nasasl walls. • When a submucous resection is perforemed surgically mucoperichondrium n mucoperiosteum are elevated before resection of septal cartilgae and bone.
  13. 13. Sphenoethmoidal recess • Lies above n behind superior concha. It receives ostium of sphenoidal air sinus. • THE SUPERIOR CONCHA. • Is extends posteriorly from its junction with middle concha. • Its lower edge is free n overlies superior meatus into which drain posterior ethmoidal air cells.
  14. 14. Middle concha • Is midway in size n position between superior n inferior. • Extends back from its junction with superior concha. • It overhangs the middle meatus. • Which can be seen only when the concha is displaced. • Behind the posterior end of middle concha the mucous membrane is the sphenopalatine foramen. • Flat area in front of the concha is atrium of nose.
  15. 15. Middle meatus • Presents a convex bulge beneath concha. • Ethmoidal bulla of ethmoid produced by buldging of middle ethmoidal air cells. • Open on or above bulla. • A curved two dimensional slit the hiatus semilunaris is present anteriorly to the bulla. • Between the anterior surface of bulla and posterior edge of uncinate process( a thin,hook like bony leaflet which projects posteroinferiorly from ethmoidal labyrinth).
  16. 16. Hiatus semilunaris • Leads into ethmoidal infundibulum, • A curved cleft bordered medially by uncinate process n laterally by orbital plate of ethmoid. • Infundibulum extends upwards n forwards n is frequently continous with frontonasal recess . • In this frontal sinus often opens. • Anterior ethmoidal cells opens into infundibulum or frontonasal recess. • Attachment of middle concha,referred by rhinologists as ground lamella of middle turbinate. • Considered as to divide ethmoidal air cells into anterior n posterior ethmoidal systems.
  17. 17. Blood supply • Sphenopalatine branch of maxillary artery. • Supplies mucosa over the conchae n meatuses n also much of septum. • Anastomosis with septal branch of labial ( entering through the nostril) n ascending branch of greater palatine ( entering through incisive canal). • Forming KISELBACH’S PLEXUS.On lower anterior part of septum.Little’s area). • A common site for epistaxis.
  18. 18. Anterior n posterior ethmoidal branches. • Of opthalmic artery enter nose from orbit and supply roof n upper parts of lateral wall n septum. • Mean while both external n internal carotid artery systems supply the nose.
  19. 19. Venous drainage • Veins accompany arteries n drain in various directions to the pterygoid plexus,facial vein n ohthalmic veins. • Rarely 1 percent an emissary vein may traverse foamen caecum in front of cribriform plate n connect nasal veins with superior sagittal sinus.
  20. 20. Lymph drainage • Lymphatics drain to submandibular,retropharyngeal n deep cervical nodes. • Nerve supply. • Olfactory ara of roof n upper parts of lateral walls n septum are supplied by olfactory nerves. • Vestibular area is supplied by the infraorbital lnerve from face.
  21. 21. The respiratory area of lateal wall nerve supply. • at front by anterior ethmidial nerve in upper part. • In lwer part by filaments from anterior superior alveolar nerve. • At the upper back aprt by lateral posterior spperior nasal branches from pterygopalatine ganglion(through sphenopalatine foramen) • At lower back part by posterior inferior nasal branches of greater palatine nerve(through foramina in perpendicular plate of ethmoid bone.