Anatomy 2

• Nasal cavity


  • Most superior part of the respiratory tract
  • Extends from the vestibule of the nose to the nasopharynx
  • Has three divisions: vestibule, olfactory region, respiratory region
• Skeleton of the nose

  • Formed by bone, cartilage, and fibro-fatty tissue
  • Divided into external nasal skeleton and internal nasal septum

  
• External Nasal Skeleton


  • Extends the nasal cavities onto the front of the face
  • Partly formed by nasal and maxillary bones
  • Inferior portion made up of hyaline cartilages

  
• Inferior portion of the nose cartilages

  • Lateral
  • Major alar
  • Minor alar
  • Cartilaginous septum

  
• Lateral and major alar cartilages

  • Largest cartilages
  • Contribute most to the shape of the nose

  
• Bony borders of the nasal cavity inlet

  • Piriform Aperture
  • Body of the Maxilla
  • Frontal process of the Maxilla
  • Nasal bone

  
• Bony borders of the nasal cavity outlet

  • Body of Sphenoid
  • Horizontal plate of the palatine bone
  • Vomer
  • Medial plate of pterygoid process

  
• Bony nasal cavity walls

  • Superior/ Roof
  • Inferior/ Floor
  • Medial/ Bony nasal septum
  • Lateral
• Lateral bony nasal cavity components

  • Frontal process of the Maxilla
  • Lacrimal bone
  • Superior and middle nasal conchae
  • Body of the Maxilla
  • Inferior nasal conchae
  • Perpendicular plate of the Palatine bone
  • Pterygoid process of the Sphenoid bone

  
• Connections of the Nasal Cavity

  • Paranasal Sinuses
  • Cribriform Plate
  • Nasolacrimal Canal
  • Sphenopalatine Foramen
  • Incisive Canal
  • Eustachian Tube

  
• Frontal sinus


  Opens into the MIDDLE NASAL MEATUS through the Anterior part of Semilunar Hiatus
• Maxillary sinus


  Opens into the MIDDLE NASAL MEATUS through the Posterior part of the Semilunar Hiatus
• Sphenoid sinus


  Opens into the COMMON NASAL MEATUS through the Sphenoethmoidal Recess
• Ethmoid sinus


  Anterior and Middle EAC open into the MIDDLE NASAL MEATUS, while the Posterior EAC open into the SUPERIOR NASAL MEATUS
• CN 1 fibers


  Olfactory fibers that pass through the Cribriform Plate
• Nasolacrimal Canal


  Opens in the INFERIOR NASAL MEATUS and connects the orbit with the nasal cavity
• Sphenopalatine Foramen


  Connects the Pterygopalatine fossa with the nasal cavity

  
• Incisive Canal

  Connects the oral cavity with the nasal cavity
• Eustachian Tube


  Opens into the Nasopharynx at the level of the inferior nasal meatus
• Soft Tissue of the Nasal Cavity

  • Divided into vestibule, olfactory region, respiratory region
• Olfactory Region


  • Covers the superior nasal concha and the septum
  • Contains fila olfactoria
• Respiratory Region


  • Rest of the nasal cavity
  • Lined with respiratory epithelium
• Blood supply of the nasal cavity

  • Anterior and Posterior Ethmoidal arteries
  • Sphenopalatine artery
• Innervation of the nose

  • Anterior and Posterior Ethmoidal nerves
  • Nasopalatine nerve
• Lymphatic drainage of the nose

  • Submandibular Lymph Nodes
  • Retropharyngeal Lymph Nodes

  
• Paranasal sinuses and kiesselbach area are clinically relevant
• Larynx


  • Organ of the conducting airway
  • Located in the anterior compartment of the neck
  • Extends from the laryngeal part of the pharynx to the trachea

  
• Laryngeal skeleton


  • Consists of cartilages joined by ligaments and membranes

  
• Vasculature and Innervation of the larynx

  • Supplied by superior and inferior laryngeal arteries
  • Receives motor and sensory innervation via branches of the vagus nerve

  
• Hyoid Bone


  • U-shaped bone located in the anterior neck
  • Does not articulate with any other bones
• Muscles attached to the Hyoid bone

  • Digastric
  • Thyrohyoid
  • Hyoglossus
  • Stylohyoid
  • Genioglossus
  • Geniohyoid
  • Sternohyoid
  • Mylohyoid
  • Middle pharyngeal constrictor
  • Omohyoid
• Epiglottic Cartilage

  • Leaf-shaped plate of Elastic Cartilage
  • Closes off the larynx during swallowing
• Thyroid Cartilage


  • Made of Hyaline Cartilage
  • Forms the Laryngeal Prominence (Adam’s Apple)

  
• Cricoid Cartilage


  • Complete ring of Hyaline Cartilage
  • Encircles the airway
• Arytenoid Cartilage


  • Paired cartilages that sit on the cricoid cartilage
  • Pyramidal shaped

  
• Laryngeal Membranes and Ligaments

  • Extrinsic and intrinsic ligaments connect laryngeal cartilages

  
• Laryngeal Folds


  • Vestibular folds and vocal folds play a role in protection and phonation
• Vocal Folds


  • Control pitch of sound
  • Avascular and appear white
• Vestibular Folds


  • Lie superiorly to vocal folds
  • Provide protection to the larynx

  
• Cricothyroid Joint


  • Adjusts human voice pitch by changing tension of vocal cords