Lecture 14 – Anatomy of Articulation.docx

Lecture 14 – Anatomy of Articulation

04.03.24

• Cavities of the Vocal tract (cont’d)
  • Buccal cavity:
    • plays a role in oral resonance and high-level consonant production
    • Lies lateral to oral cavity between teeth and cheeks
  • Pharyngeal cavity (pharynx)
    • Shape altered by pharyngeal constrictor muscle, laryngeal elevation and depression
    • Type of pharyngeal cavities
      • Nasopharynx – above the soft palate, contains pharyngeal tonsils (adenoids); lateral wall contains Eustachian tube – aerates the middle ear
      • Oropharynx – posterior to fauces, above is velum
      • Laryngopharynx (hypopharynx) – anterior epiglottis, inferior esophagus
    • Velopharyngeal port (VPP) – opening between oropharynx and nasopharynx
• Q: what is the primary function of the nasal cavity (apart form smell)?
  • A: warm air: protect lungs
  • B: humidify air: protect lungs
  • Also helps prevent particles from entering respiratory trac (filters air) and helps in vowel production but these aren’t exactly the “primary functions”
• Cavities (cont’d)
  • Nasal cavities
    • Warms and humidifies air to protect the lungs
    • Fine nasal hairs prevent particles form entering lower respiratory tract
    • Nares – anterior boundary; floor is hard palate
    • Nasal choanae – posterior portals connecting nasopharynx and nasal cavities
• Muscles of the face and mouth
  • Tongue and mouth muscles
    • Tongue
    • Velum
    • (pharynx)
  • Lips and lip muscles
    • Movement for speech depends on muscle of the face
    • Important in both facical expression and speech
    • Richly invested with vascular supply
    • Have social,cultural and aesthetic value
  • (Face muscles)
  • Mandible muscles
• Q: which of the two lips is more mobile and stronger?
  • B: lower lip
• Lips
  • The lower lip versus the upper lip
    • The lower lip is
    • Faster and stronger than the upper lip
    • Achieves a greater velocity and force
    • Does most of the work in lip closure
    • Attached to the mandible – a moveable articulator
    • Can accommodate a variety of jaw positions
    • Resistant to interference
  • Lip muscles
    • Orbicularis oris – encircling mouth opening
    • Risourius – superficial – retracts corner of mouth
    • Buccinator – deep to resourius, retracts corner of mouth, involved in mastication
    • Levator labii superioris, zygomatic minor, levator labii superioris, alaeque nasi – elevate upper lip
    • Levator anguli oris – draw mouth up and medially
    • Zygomatic major – elevate and retract angle of the mouth – smiling
    • Depressor labii inferioris – pull lip down and out
• The mandible – structure and landmarks
  • 
  • Q: why is the mylohyoid line called like that?
    • \o/
    • A: it is the anatomical boundary between myloid and hyoid – WRONG
    • C: it is the site of origin of the mylohyoid muscle
    • It is a bony ridge on the internal surface of the mandible
  • 
  • Plays a role in speech (🡪 jaw opening and closing)
    • Assists the lips – important supportive role
    • Changes position for tongue movement
    • Can tightly close when necessary
    • Position for speech is one of dynamic tension between antagonists
  • Mandibular elevator muscles have muscle spindles
    • Helps to counteract gravity
  • Plays major role in mastication
    • Central pattern generator within brainstem
      • Produced muscular contraction for chewing
      • Must elevate, grind laterally and depress
        • Requires coordinated activation of elevators and depressors