Nose & Paranasal Sinuses PDF

Assoc. Prof. Dr. Azian Abd Latiff Department Of Anatomy Medical Faculty, UKM EXTERNAL NOSE vFeatures : v Root of the nose (attached to the forehead) v Dorsum of the nose v Apex / tip v Naris (nostril) : bounded by ala and nasal septum v Nasal septum ...

Assoc. Prof. Dr. Azian Abd Latiff Department Of Anatomy Medical Faculty, UKM EXTERNAL NOSE vFeatures : v Root of the nose (attached to the forehead) v Dorsum of the nose v Apex / tip v Naris (nostril) : bounded by ala and nasal septum v Nasal septum  Winglikeprocess EXTERNAL NOSE v Framework (cartilaginous and bony parts): v Lateral v Septal cartilages v Alar v Nasal bones v Frontal processes of the maxillae bones v Nasal part of the frontal bone & its nasal spine v Bony nasal septum  Frontal process of maxilla Nasal bone Septal nasal cartilage Framework of the external nose  NASAL CAVITY v Roof v Middle part - formed by the cribriform plate of ethmoid bone v Anterior part - nasal part of frontal bone, nasal bone & cartilages v Posterior part -inferior surface of body of sphenoid NASAL CAVITY v Lateral wall v Separates the nasal cavity from the: v orbit v maxillary sinus v Characteristic features: v vestibule (anterior portion lined by skin with soft hair à vibrissae) v posterior part à choanae internal space forcing air to flowin a v 3 bony projections à conchae (turbinates) steady regular pattern  NASAL CAVITY v Floor formed by: v palatine process of maxilla v horizontal plate of palatine bone v Medial wall (nasal septum) v Divides the nasal cavity into 2 parts v Consists of : v bony part à vomer & perpendicular plate ethmoid v cartilaginous part  Nerve supply of nasal septum Internal nasal branch of anterior ethmoidal nerve (branch of V1) - provides general sensory to anterosuperior part of nasal septum olfactory nerves (15 – 20 bundles) - provides smell sensation E from maxillary 1 nerve Nasopalatine nerve (branch of V2) provides general sensory lo optic to posteroinferior part of nasal septum Sagittal section showing the left nasopalatine nerve in situ after removal of the nasal septum. Nerve supply of lateral wall of nasal cavity v Smell : olfactory nerve v general sensation Anterior ethmoidal nerve (branch of V1) Posterior lateral nasal nerve à supplies anterosuperior part (branch of V2) à posterosuperior part Anterior palatine nerve (branch of V2) Anterior superior alveolar nerve (branch of V2) àposteroinferior part à anteroinferior part v Secretomotor : preganglionic fibres from superior cervical ganglion and postganglionic fibres from pterygopalatine ganglion  ARTERIAL SUPPLY TO NASAL CAVITY Anterior ethmoidal artery Anterior ethmoidal (from ophthalmic artery) artery à Supplies anterosuperior part à anterosuperior part lateral nasal branch (from facial artery) Septal branch of superior labial à vestibule artery (from facial artery) Sphenopalatine à Supplies anteroinferior part artery Greater palatine artery (from maxillary artery) (from maxillary artery) à Supplies posteroinferior part Arterial supply to lateral wall of nasal cavity à Supplies Arterial supply to nasal septum posterosuperior part of nasal septum v locatedinnasalcavity à Supplies posterosuperior & whereseveral arteriesanastomose posteroinferior parts of lat wall of nasal cavity toformplexus orvascular networkRuptureofthis area causesnosebleeds Liesselbach's area ethmoidal  p artery sphenopalatine ry EPISTAXIS nosebleed greaterpalatineartery septalbranchof superior labialartery vCommonest site : v anterior third of the nose (Kiesselbach’s plexus/Little’s area) v An area which is supplied by an anastomosis of branches from 5 different arterial sources: v Sphenopalatine artery (maxillary artery) v Anterior and posterior ethmoidal artery (ophthalmic artery) v Greater palatine artery (maxillary artery) v Superior labial artery (facial artery) v Lateral nasal branch (facial artery) RHINITIS v nasal mucosa becomes swollen and inflamed v causes : upper respiratory infections : allergic reactions (hay fever) NORMAL ABNORMAL PARANASAL SINUSES v Air-filled extensions of respiratory part of the nasal cavity into the cranial bones. v Paired but asymmetrical. v Lined by respiratory epithelium. v Various functions : air-conditioning chambers, resonating chambers, lighter bones v Bones involved are : v frontal* v sphenoidal v ethmoidal v maxilla SPHENOIDAL SINUS v A septum separates the left and right sinus v Located in the sphenoid bone ( bone is fragile) v Superior relations : optic chiasma : pituitary gland v Lateral relations : internal carotid artery : cavernous sinus v Behind : pons and medulla oblongata v Age 6 : size of a small pea v Blood supply : posterior ethmoidal vessels Relationships of sphenoid sinuses with adjacent structures ETHMOIDAL SINUSES v 3 – 18 small interconnected air spaces v 3 groups : anterior, middle & posterior v Lateral relations: orbital plate of ethmoid v Blood supply : anterior and posterior ethmoidal branches of ophthalmic artery Ethmoidal sinuses (coronal section of the head) anopening intoa really orcavityof thebody Ethmoidal sinuses (coronal CT scan) FRONTAL SINUSES v Two in number v Extends: v upward and above the medial end of the eyebrow v backward into the medial part of the roof of the orbit v Blood supply : supra-orbital vessels v Nerve supply : supra-orbital nerves Frontal sinus (medial view of nasal cavity) MAXILLARY SINUSES v Largest and first to be formed v Pyramidal shaped v Roof : orbital surface of maxilla (traversed by infra-orbital nerve and vessel) v Floor : alveolar process of maxilla ** closely related to roots of premolar and molar teeth v Posterior wall : anterior wall of infratemporal fossa (pierced by posterior superior alveolar vessels and nerves) v Blood supply : anterior, middle and posterior superior alveolar vessels of maxillary artery v Nerve supply : similar to teeth (anterior, middle and posterior superior alveolar nerves) Left maxillary sinus opened from exterior  Relations Superior - Orbit - Infraorbital nv & vessels Inferior - Roots of molars & PM Medially - Nasal cavity Laterally & anteriorly - Cheek Maxillary sinuses (coronal section of the head) Maxillary sinuses (coronal CT scan) The maxillary nerve and artery, seen after excision of part of the lateral walls of the orbit and maxillary air sinus.  Blood supply Maxillary posterior artery Superior alveolar middle arteries anterior External carotid artery  Nerve supply V3 Infraorbital Nv Ant superior alv. nv. Post superior alv. nv. OPENINGS of the PARANASAL SINUSES v Meatus : space beneath the concha v Inferior meatus v Largest : lies beneath the inferior concha v Opening of the nasolacrimal duct v Middle meatus v Beneath the middle concha v Receives the openings from: maxillary sinus, ant & middle ethmoidal sinus, frontal sinus. Mucus secretion within maxillary sinus drains through Middle maxillary sinus opening (ostium) à which opens into infundibulum meatus à Later opens into hiatus semilunaris & à Finally the secretion from max sinus drains into middle meatus  Sphenoethmoidal recess Openings of : Post. ethmoidal sinus Mid. ethmoidal sinus Lateral wall of the nose seen after removing the conchae v Superior meatus v Shortest; lies beneath the superior concha v Opening of the posterior ethmoidal sinus v Sphenoethmoidal recess v Above the superior concha v Opening of the sphenoidal sinus  Applied Anatomy Maxillary sinusitis U inflamation of paranased sinners caused a virus by Sinusitis : detected by radiological examination fluid in Yim Endoscopic sinus surgery u a procedureto remove blockages and treat other problems in the sinuses using an endoscope Uncinate process fOsteomeatal obstruction finalpathway for offrontal Stump of drainage uncinate process Max antethmoidal cells Incision is made by exposing d osteomeatal complex Eliminate external excision Greater amount of normal tissue intact  Oroantral fistula abnormal opening A Coronal CT scan of the sinuses, showed a defect in the floor of the left maxillary antrum, corresponding to the oroantral fistula. Note the opacification of the maxillary sinus, indicating chronic infection.