MOUTH

• Lips


  Two fleshy folds that surround the oral orifice, covered on the outside by skin and lined on the inside by mucous membrane, made up of the orbicularis oris muscle and muscles radiating into the face, also include labial blood vessels, nerves, connective tissue, and small salivary glands
• Philtrum


  Shallow vertical groove seen in the midline on the outer surface of the upper lip
• Labial frenulae


  Median folds of mucous membrane that connect the inner surface of the lips to the gums
• Mouth


  Extends from the lips to the pharynx, divided into the vestibule and the mouth cavity proper
• Oropharyngeal isthmus


  The entrance into the pharynx, formed on each side by the palatoglossal fold
• Vestibule


  The slitlike space between the lips and cheeks externally and the gums and teeth internally, communicates with the exterior through the oral fissure and with the mouth proper behind the third molar tooth
• Buccinator muscle


  Forms the lateral wall of the vestibule, keeps the walls in contact with each other
• Parotid salivary gland duct

  Opens on a small papilla into the vestibule opposite the upper second molar tooth
• Hard palate


  Formed by the palatine processes of the maxillae and the horizontal plates of the palatine bones, continuous with the soft palate
• Soft palate


  A mobile fold attached to the posterior border of the hard palate, presents a conical projection called the uvula, continuous with the lateral wall of the pharynx
• Palatine aponeurosis


  A fibrous sheet attached to the posterior border of the hard palate, the expanded tendon of the tensor veli palatini muscle
• Muscles of the soft palate

  • Tensor veli palatini
  • Levator veli palatini
  • Palatoglossus
  • Palatopharyngeus
  • Musculus uvulae
• Palatoglossal arch


  A fold of mucous membrane containing the palatoglossus muscle, extends from the soft palate to the side of the tongue, marks where the mouth becomes the pharynx
• Palatopharyngeal arch


  A fold of mucous membrane behind the palatoglossal arch that runs downward and laterally to join the pharyngeal wall, contains the palatopharyngeus muscle
• Palatine tonsils


  Masses of lymphoid tissue located between the palatoglossal and palatopharyngeal arches
• Movements of the soft palate

  Soft palate raised by contraction of levator veli palatini, upper fibers of superior constrictor muscle contract to pull posterior pharyngeal wall forward, palatopharyngeus muscles contract to pull palatopharyngeal arches medially, closing off nasal part of pharynx from oral part
• Salivary glands


  A group of exocrine glands in the mouth that produce saliva, a watery substance containing enzymes, mucus, and other substances
• Palatopharyngeal arch


  • Fold of mucous membrane covering the palatopharyngeus muscle
• Palatoglossal arch


  • Fold of mucous membrane covering the palatoglossus muscle
• Closure of the pharyngeal isthmus

  1. Raising of the soft palate

  2. Contraction of the levator veli palatini

  3. Contraction of the upper fibers of the superior constrictor muscle

  4. Contraction of the palatopharyngeus muscles
• Pharyngeal isthmus


  Communicating channel between the nasal and oral parts of the pharynx
• Salivary glands


  • Group of exocrine glands in the mouth that produce saliva
  • Saliva is a watery substance that contains enzymes, mucus, and other substances
  • Primary function is to lubricate food and aid in the process of digestion
• Parotid gland


  • Largest salivary gland
  • Composed mostly of serous acini
  • Located in a deep hollow below the external auditory meatus, behind the ramus of the mandible, and in front of the sternocleidomastoid muscle
  • Facial nerve divides the gland into superficial and deep lobes
  • Parotid duct emerges from the anterior border of the gland and passes forward over the lateral surface of the masseter, entering the vestibule of the mouth upon a small papilla opposite the upper second molar tooth
• The parotid duct is a comparatively superficial structure on the face and may be damaged in injuries to the face or inadvertently cut during surgical operations on the face
• A benign parotid neoplasm rarely, if ever, causes facial palsy, but a malignant tumor of the parotid is usually highly invasive and quickly involves the facial nerve, causing unilateral facial paralysis
• The parotid gland may become acutely inflamed as a result of retrograde bacterial infection from the mouth via the parotid duct or via the bloodstream, as in mumps
• Frey's syndrome is an interesting complication that sometimes develops after penetrating wounds of the parotid gland, where the patient experiences beads of perspiration on the skin covering the parotid when eating
• Submandibular gland


  • Consists of a mixture of serous and mucous acini
  • Lies beneath the lower border of the body of the mandible
  • The deep part of the gland lies beneath the mucous membrane of the mouth on the side of the tongue
  • The submandibular duct emerges from the anterior end of the deep part of the gland and opens into the mouth on a small papilla at the side of the frenulum of the tongue
• Submandibular ganglion


  Provides parasympathetic secretomotor supply to the submandibular and sublingual glands
• Sublingual gland


  • Lies beneath the mucous membrane (sublingual fold) of the floor of the mouth, close to the frenulum of the tongue
  • Has both serous and mucous acini, with the latter predominating
  • The sublingual ducts (8 to 20 in number) open into the mouth on the summit of the sublingual fold
• Blockage of one of the small ducts of the sublingual salivary gland is believed to be the cause of cysts under the tongue
• Pharynx


  • Situated behind the nasal cavities, the mouth, and the larynx
  • Divided into nasal, oral, and laryngeal parts
  • Funnel shaped, with the upper, wider end lying under the skull and the lower, narrow end becoming continuous with the esophagus
  • Has a musculomembranous wall, which is deficient anteriorly and replaced by the posterior openings into the nose, mouth, and larynx
• Muscles of the pharynx

  • Superior, middle, and inferior constrictor muscles with fibers running in a somewhat circular direction
  • Stylopharyngeus and salpingopharyngeus muscles with fibers running in a somewhat longitudinal direction
  • The three constrictor muscles overlap each other and are inserted into a fibrous band or raphe
  • The lower part of the inferior constrictor is called the cricopharyngeus muscle, which acts as a sphincter
• Killian's dehiscence is the area on the posterior pharyngeal wall between the upper propulsive part of the inferior constrictor and the lower sphincteric part, the cricopharyngeus
• Nasal pharynx


  • Lies above the soft palate and behind the nasal cavities
  • Contains a collection of lymphoid tissue called the pharyngeal tonsil in the submucosa of the roof
• Pharyngeal isthmus


  • Opening in the floor between the soft palate and the posterior pharyngeal wall
• Tubal elevation


  • Elevated ridge on the lateral wall where the opening of the auditory tube is located
• Pharyngeal recess


  • Depression in the pharyngeal wall behind the tubal elevation
• Salpingopharyngeal fold


  • Vertical fold of mucous membrane covering the salpingopharyngeus muscle
• Oral pharynx


  • Lies behind the oral cavity
  • The floor is formed by the posterior one third of the tongue and the interval between the tongue and epiglottis
  • Contains the median and lateral glossoepiglottic folds and the vallecula