Oral cavity Vestibule. Slit like space bound by ; Lips and cheeks externally Teeth and gum internally Opens outside by oral fissure.
Oral cavity Lips; two soft folds surround the oral fissure. Covered by skin externally, and mucous membrane internally. Containing orbicularis oris. Cheeks; lie on each side oral fissure. Gums; dense fibrous tissue attached to alveolar borders of the jaws, adherent to necks of teeth.
Oral cavity Teeth ; Primary, deciduous ” milk ” teeth Twenty in number in both jaws. Emerge 6 mos. – 2 yrs. Replaced by permanent teeth 6- 12 yrs. Permanent, thirty two in both jaws. Replace the milk teeth at 6 yrs. Wisdom teeth (3 rd molar) erupts 17-25 yrs or remains in jaw.
Mouth cavity proper Anteriorly and laterally bounded by teeth, gum and alveolar arches. Posteriorly oropharyngeal isthmus, communicates it with the oropharynx. Roofed by hard and soft palate. Floor is formed by anterior 2/3 of tongue, and mucous membrane of sides and under surface of the tongue.
Floor of the mouth Frenulum linguae is a median mucus fold in the under surface of the tongue, joins it with the floor Lingual fold is a mucus ridge on each side of the frenulum linguae Sublingual papilla is a rounded elevation on the anterior end of the sublingual fold, in its summit open the submandibular duct.
Roof of the mouth Hard palate – forms the anterior two thirds. Soft palate – forms the posterior third. Uvula – fleshy median projection of the soft palate.
Palate Forms the roof of the mouth The anterior two-thirds is the hard palate. The posterior one third is the soft palate. Its nasal surface forms the floor of the nasal cavity.
Palate Hard palate; Formed by palatine bones and palatine processes of the maxillae
Palate Soft palate; mobile fold formed mostly of skeletal muscle Closes off the nasopharynx during swallowing Uvula projects downward from its free edge Palatoglossal and palatopharyngeal arches form the borders of the fauces
Muscles of the palate Levator veli palatini Tensor veli palatini Palatoglossus Palatopharyngeus. Musculus uvulae
Muscles of the palate Levator veli palatini Tensor veli palatini Palatoglossus Palatopharyngeu. Musculus uvulae
Nerve supply Sensory ; Greater palatine. Lesser palatine Nasopalatine. Pharyngeal branch of glossopharyngeal. Motor; Cranial part of accessory through pharyngeal plexus (except tensor palati by mandibular).
Tongue Occupies the floor of the mouth and fills the oral cavity when mouth is closed Functions include: –Mixing food with saliva and forming the bolus. –Initiation of swallowing. –Speech.
Tongue Intrinsic muscles change the shape of the tongue Extrinsic muscles alter the tongue ’ s position Lingual frenulum secures the tongue to the floor of the mouth
Dorsum of the tongue The dorsum of the tongue is divided into Palatine part, the anterior 2/3, it is rough due to lingual papillae. Pharyngeal part, posterior 1/3, it is smooth and nodular. Sulcus terminalis is a v shaped sulcus, at its apex lie foramen caecum.
Muscles of the tongue Extrinsic muscles; Genioglossus Hyoglossus Styloglossus palatoglossus.
Muscles of the tongue Intrinsic muscles; Longitudinal. Transverse. Vertical.
Nerve supply Sensory; Anterior 2/3 Lingual. (general sensation). Chorda tympani ( taste sensation). Posterior 1/3 Glossopharyngeal ( general and taste sensation). Most posterior part by superior laryngeal of vagus.
Nerve supply Motor Hypoglossal nerve; all intrinsic and extrinsic muscles. Except palatpglossus by pharyngeal plexus.