Anatomy of the Nose PDF

ANATOMY OF THE NOSE NOSE - Uppermost part of respiratory tract - Peripheral organ of smell PARTS - External nose - Nasal cavity FUNCTIONS OF NOSE - Respiration...

ANATOMY OF THE NOSE NOSE - Uppermost part of respiratory tract - Peripheral organ of smell PARTS - External nose - Nasal cavity FUNCTIONS OF NOSE - Respiration - Olfaction - Protection lower respiratory passage - Conditioning the inspired air - Vocal resonance - Nasal reflex function (sneezing) STRUCTURE ASSOCIATED LAB/ LECTURE PHOTO EXTERNAL NOSE Pyramidal projection in the mid face Parts: I. Tip/ Apex- the lower free end. II. Root/ Bridge – the upper narrow part which is continuous w/the forehead. III. Dorsum – a round border between the tip and root. IV. Nostrils/ Nares – the 2 piriform apertures at the broad lower end. Bounded: - Medially by the mobile part of the nasal septum/ columella - Laterally by the ala of the nose. V. Ala – the lower flared part on the side of the nose. SKIN - The skin covering the nose is thin and loosely attached to the underlying structure. - Over the apex and alae it is thicker and more adherent and contains large sebaceous glands. NB: Hypertrophy of these sebaceous glands gives rise to a lobulated tumour– the rhinophyma (draw in arrow to nose pic) SKELETON - Upper 1/3 of external nose is bony. - Lower 2/3 is cartiligious. BONY FRAMEWORK: (formed by) - Two nasal bones (nose bridge) - Frontal process of the maxillae - Bony part of external nose terminates in front and below as the piriform aperture. CARTILAGINOUS PART (formed by) - Five main cartilages - Several additional tiny cartilaginous. Five main cartilages: 1. Two lateral cartilages – superior lateral cartilages 2. Single median septal cartilage 3. Two major alar cartilages - inferior lateral cartilages. (Minor alar or sesamoid cartilages) NB: The cartilaginous tissue is anchored to the piriform aperture by fibrous tissue. Lateral Cartilages articulate: - Frontal process of maxilla and nasal bone - Below w/the major alar cartilages - Medially w/the septal cartilage. NB: There are two or more tiny cartilages - Minor alar or Sesamoid cartilages BLOOD SUPPLY OF NOSE Arteries of nose: 1. Dorsal nasal branch of ophthalmic artery 2. Infra-orbital branch of maxillary artery 3. Alar and septal branches of facial artery SENSORY NERVE SUPPLY OF NOSE 1. External/dorsal nasal and infra- trochlear branches of ophthalmic nerve 2. Infra-orbital branch of maxillary nerve MUSCLES I. Procerus - Continuation of medial part of frontalis - It produces transverse wrinkles across the bridge of nose in frowning II. Nasalis (consists of 2 parts) a. Transverse part (compressor naris). - Compresses the nasal aperture. b. Depressor septi - Dilates the anterior nasal aperture - Active in anger NB: These muscles are derived from second arch hence supplied by the facial nerve.