1. Lateral wall of nose
    1. Skeleton of lateral wall is partly bony, cartilaginous & soft tissues
      1. Bones: 1.Nasal 2.Maxilla: frontal process 3.lacrimal 4.labyrinth of ethmoid with superior & 5.middle conchae 6.Inferior nasal concha made of spongy bone only 7.perpendicular plate of palatine bone 8.Medial pterygoid plate
      2. Cartilaginous part formed by 1. Superior nasal cartilage 2. Inferior nasal cartilage 3. 3 or 4 small cartilage of ala
    2. Conchae & meatus
      1. Nasal Conchae : Are curved bony projections directed downwards & medially. 3 types of conchae are found
        1. 1. Inferior concha : An independent bone
        2. 2. Middle concha: projection from medial surface of ethmoidal labyrinth
        3. 3. Superior concha: projection from medial surface of ethmoidal labyrinth. Smallest concha, present above post. Part of middle concha
      2. Meatus of nose: passages beneath the overhanging conchae. They communicates freely with nasal cavity proper
        1. 1. Inferior meatus: a. lies underneath the inferior concha b. largest meatus c. Nasolacrimal duct opening
        2. 2 . Middle meatus a. Lies underneath middle concha b. It presents following features * Ethmoidal bulla * Hiatus semilunaris *.Infundibulum * Opening of frontal air sinus, anterior ethmoidal air sinus, maxillary air sinus
        3. 3. Superior meatus a. Lies below superior concha b. Shortest and shallowest c. Receives opening of post. Ethmoidal air sinuses.
      3. Arterial supply
        1. 1. Anterosuperior quadrant : by ant ethmoidal artery & post ethmoidal artery 2. Anteroinferior quadrant : Facial artery 3. Posterosuperior quadrant: Sphenopalatine artery 4. Posteroinferior quadrant: Greater palatine artery
      4. Venous Drainage
        1. Veins form a plexus which drains Anteriorly : in Facial vein Posteriorly : Pharyngeal plexus of veins Middle part: Pterygoid plexus of veins
      5. Nerve Supply
        1. General sensory : From branches of trigeminal nerve a. Anterosuperior quadrant: Ant. Ethmoidal nerve from ophthalmic nerve b. Anteroinferior quadrant: Anterior superior alveolar nerve, branch of infraorbital nerve c. Posterosuperior : Lateral posterior superior nasal nerve of pterygopalatine ganglion d. Posteroinferior quadrant: Anterior palatine nerve pterygopalatine ganglion
        2. Special sensory nerve / olfactory nerves are present just below cribriform plate
      6. Lymphatics: submandibular , retropharyngeal, upper deep cervical LN
  2. Paranasal sinuses
    1. Air filled spaces present around nasal cavity
      1. Function: make skull lighter, warm up & humidify air & add resonance to voice
    2. 4 important sinuses
      1. Frontal sinus present in frontal bone 1. Opens into middle meatus of nose 2. Arterial supply: supraorbital artery 3. Venous drainage: supraorbital & superior opthalmic veins 4. Nerve: supraorbital N 5. Lymphatics: submandibular LN
      2. Maxillary sinus largest of all sinus floor formed by palare & roof by orbit 1. Opens into middle meatus 2. Artery : Facial, infraorbital & greater palatine artery 3. Veins: facial vein & pterygoid plexus of veins 4. Nerve: PSA branch of maxillary nerve & ASA & MSA branches from infraorbital nerve 5. Lymphatic drainage: submandibular LN
        1. Infection from maxillary teeth especially canine reach sinus & cause sinusitis pain may be reffered to upper teeth and infraorbital skin
      3. Sphenoidal sinus present in body of sphenoid 1. Opens in sphenoethmoidal recess 2. Artery : post ethmoidal & internal carotid artery 3. Veins: pterygoid venous plexus & cavernous sinus 4. Nerve: posterior ethmoidal nerve & orbital branch of pterygopalatine ganglion 5. Lymphatic drainage: Retropharyngeal LN
      4. Ethmoidal sinus Are multiple and lie within labyrinth of ethmoid bone Divided into 3 groups
        1. 1. Anterior ethmoidal group : opens into ant part of hiatus semilunaris. supplied by ant ethmoidal nerve & vessels drains into submandibular LN
        2. 2. Middle ethmoidal sinus: opens into middle meatus. Supplied by ant ethmoidal nerve & vessels & orbital branch of pterygopalatine ganglion drains into Submandibular LN
        3. 3. Posterior ethmoidal sinus :opens into superior meatus of nose supplied by post ethmoidal nerve & vessels & orbital branches of pterygopalatine ganglion drains into retropharyngeal LN
        4. Pain from ethmoidal sinus can be referred to forehead
  3. Nose
    1. External Nose
      1. Has skeletal framework that is partly bony & partly cartilaginous.
        1. Bones: Nasal bridge & the frontal process of maxilla Cartilage: Superior & inferior nasal cartilages, septal cartilage & small alar cartilages.
        2. Cartilage : sperior nasal & Inferior nasal cartilage , alar cartilage, septal cartilage
      2. Skin over external nose is supplied by External nasal, infratrochlear & infraorbital nerves
    2. Nasal Cavity
      1. It’s subdivided into right & left halves by nasal septum.
      2. Parts : roof Floor Lateral & medial walls
        1. Roof: formed by Cribriform plate of ethmoid, frontal bone, nasal bone & cartilage. Post surface by body of sphenoid
          1. CSF Rhinorrhoea: CSF drip from nasal cavity because of fracture of cribriform plate
        2. Floor : formed by palate
        3. Medial wall : formed by septum
          1. 1. Median osseocartilaginous partion between nasal cavity 2. Bony part formed by: Vomer & perpendicular plate of ethmoid 3. Cartilagenous part formed by : septal cartilage & septal part of inf. Nasal cartilage 4.lower margin of septum is called columella
          2. Deviation of Nasal septum is responsible for repeated attacks of common cold, allergic rhinitis, sinusitis & requires surgical correction
    3. Olfactory mucosa lines the upper 1/3 rd of the nose & responsible for smell
    4. Respiratory mucosa: purifies air
    5. Arterial supply
      1. Anterosuperior part
        1. Ant & post Ethmoidal artery
      2. Anteroinferior part
        1. Facial artery —> superior labial—>septal branch
      3. Posterosuperior part
        1. Sphenopalatine artery & is main artery
      4. Anteroinferior part/ vestibule of septum
        1. Anastomoses between : septal artery, sphenopalatine artery & ant & post Ethmoidal artery forms a capillary network called KIESSELBACH’s plexus, Common site of epistaxis , and this area is called LITTLE’s area.
    6. Venous Drainage
      1. Veins form a plexus in little’s area. Plexus drains anteriorly into facial vein & posteriorly through sphenopalatine vein to pterygoid venous plexus.
    7. Nerve Supply
      1. General sensory nerves
        1. Anterosuperior : Ant. Ethmoidal N
        2. Posteroinferior ( Main N): Nasopalatine branch of Pterygopalatine ganglion.
      2. Special sensory nerves
        1. Olfactory nerve, in upper part
    8. Lymphatic Drainage
      1. Anterior half : Submandibular nodes
      2. Posterior half to retropharyngeal & deep cervical nodes.