ORAL+NASAL CAVITY

• Oral cavity


  Inferior to the nasal cavities and includes: teeth, gingivae, tongue, palate, region of palatine tonsils

  
• Oral cavity


  • Has a roof and floor and lateral walls, opens onto the face through the oral fissure, and is continuous with the cavity of the pharynx at the oropharyngeal isthmus

  
• Oropharyngeal isthmus


  At the back of the oral cavity proper, can be opened and closed by surrounding soft tissues, which include the soft palate and tongue

  
• Oral cavity


  • Separated into two regions by the upper and lower dental arches consisting of the teeth and alveolar bone that supports them: the outer oral vestibule, which is horseshoe shaped, is between the dental arches and the deep surfaces of the cheeks and lips; the inner oral cavity proper is enclosed by the dental arches

  
• Functions of the oral cavity

  • Formation of bolus (mastication, lingual manipulation), voluntary deglutition, involuntary deglutition, manipulation of sound from larynx

  
• Oral cavity proper


  • Roof: hard and soft palates; Floor: mylohyoid, geniohyoid and the tongue; Laterally and anteriorly: upper and lower dental arches and alveolar bone; Lateral walls (cheeks) are muscular and merge anteriorly with the lips surrounding the oral fissure (the anterior opening of the oral cavity)

  
• The oral cavity is inferior to the nasal cavities
• The oral cavity includes teeth, gingivae, tongue, palate, and region of palatine tonsils

  
• The oral cavity opens onto the face through the oral fissure and is continuous with the cavity of the pharynx at the oropharyngeal isthmus

  
• The oropharyngeal isthmus can be opened and closed by surrounding soft tissues, which include the soft palate and tongue
• The oral cavity is separated into two regions by the upper and lower dental arches consisting of the teeth and alveolar bone that supports them

  
• The outer oral vestibule is between the dental arches and the deep surfaces of the cheeks and lips

  
• The inner oral cavity proper is enclosed by the dental arches

  
• The roof of the oral cavity proper is the hard and soft palates

  
• The floor of the oral cavity proper is the mylohyoid, geniohyoid and the tongue

  
• The lateral walls (cheeks) of the oral cavity proper are muscular and merge anteriorly with the lips surrounding the oral fissure

  
• The palate forms the roof of the oral cavity and floor of the nasal cavity

  
• Hard palate
• Anterior 2/3 à palatine process of maxilla bones

  
• Posterior 1/3 à horizontal plates of palatine bones

  
• Above, it is covered by respiratory mucosa and forms the floor of the nasal cavities.
• Below, it is covered by a tightly bound layer of oral mucosa and forms much of the roof of the oral cavity
• The mucosa of the hard palate in the oral cavity possesses numerous transverse palatine folds (palatine rugae) and a median longitudinal ridge (palatine raphe)
• Soft palate:
• Movable à by four muscles (*palatoglossus is muscle of tongue)
• Suspended to hard palate by palatine aponeurosis
• Has soft free margin à uvula
• Acts as a valve:
• Inferiorly: depressed to help close the oropharyngeal isthmus
• Superiorly: elevated to separate the nasopharynx from the oropharynx.
• It consists of a bony plate covered above and below by mucosa
• Embedded palatine glands secrete saliva
• The floor of the oral cavity proper is formed mainly by three structures:

  
• A muscular diaphragm, composed of the paired mylohyoid muscles
• Two cord-like geniohyoid muscles above the diaphragm
• The tongue, which is superior to the geniohyoid muscles.
• Also present in the floor of the oral cavity proper are salivary glands and their ducts. The largest of these glands, on each side, are the sublingual gland and the oral part of the submandibular gland.

  
• Chapter 7 • Head
• Tensor veli palatini
• Levator veli palatini