Velopharyngeal- Nasal Function

Velopharyngeal- Nasal Function

1. Speech

   • Open velopharyngeal port
     • Allows air through nasal cavitiy
   • Closed velopharyngeal port
     • Allow high air pressure for oral sounds

2. Development

   • Kids
     • Velum and epiglottis separate as larynx moves down
     • Infants are preferential nasal breathers
     • Velopharynx closes occasionally for vocalaisation as early as 2 months
     • By 20 months
       • Velopharynx closes for oral sound production nearly all the time
     • Nasopharyngeal tonsils (adenoids)
       • Grow during childhood then atrophy
   • Ageing
     • No apparent change in velopharyngeal function for speech production
     • Anatomical changes may affect certain acoustic features associated with nasalisation
       • e.g. tissue and bone atrophy, age-related changes in pharyngeal and oral cavity size
   • Soft Palate (velum)
     • Impairments
       • Cleft of soft palate
       • Bifid uvula
       • Velopharyngeal Incompetence
         • Difficulty achieving velopharyngeal closure
           • Hypernasality and nasal emission
   • Nose
     • Impairments
       • Blocked nasal cavity
         • Hyponasal speech
       • Hypernasal Speech
         • Velum doesn't have adequate closure to divide nasal and oral cavity
   • Pharynx
     • Impairments
       • Hypernasal
         • following adenoidectomy
       • Hyponasal
         • Enlarged adenoid

3. Pharynx

   • From larynx to nasal cavity
   • Mostly connective tissue at top; mostly muscle at bottom
   • Continuous with espohagus
   • 3 Cavities
     • Nasopharynx
       • Lower boundaries level with hard palate
       • Contains auditory tubes & nasopharyngeal tonsil
     • Oropharynx
       • Hyoid Bone
     • Laryngopharynx
       • Base of Cricoid Bone
   • Muscles
     • Important for swallowing
     • 6
       • Superior Constrictor
         • From multiples sites at front of pharyngeal tube
           • Inserts into median raphe of posterior pharyngeal wall
         • Constricts pharynx
       • Middle Constrictor
         • From greater and lesser horns of hyoid bone and stylohyoid ligament
           • To median raphe of posterior pharyngeal wall
         • Constricts pharynx
       • Inferior Constrictor
         • From sides of thyroid and cricoid cartilages
           • Inserts into median raphe of posterior pharyngeal wall
         • 2 parts
           • Thyropharyngeus
             • Upper
           • Cricopharyngeus
             • Lower
         • All 3 pull pharyngeal walls in and forward to constrict
       • Salpingopharyngeus
         • From lower border of pharyngeal orifice of auditory tube
           • To lateral pharyngeal wall(where it blends with fibres of palatopharyngeus musce
         • Pulls lateral pharyngeal walls up and in
       • Stylopharyngeus
         • From styloid process of temporal bone
           • Inserts in lateral pharyngeal wall near juncture of superior and middle constrictor muscles and into thyroid cartilage
         • Pulls up on pharynx up, and the lateral walls outward (widens pharynx)
       • Palatopharyngeus
         • From soft palate and some fibres run horizontally and intermingle with superior constrictor fibres and others run through the posterior faucial pillars
           • To lower wall of the pharynx and thyroid cartilage
         • Pulls inward on upper pharyngeal walls and upward on lower lateral pharyngeal walls (with velum fixed)

4. Velum

   • If short
     • Soft palate doesn't connect and shut off nasal cavity
       • Lets air escape through nose
   • Muscles
     • Palatal Levator (Levator veli palanti)
       • Paired muscle
         • Sling
       • Draws velum up and back
     • Palatal Tensor (Tensor veli palanti)
       • Inserts into hard palate
       • Opens auditory tube
     • Uvulus
       • Intrinsic Muscle
       • Contraction shortens, lift and thickens velum
     • Glossopalantine
       • Pulls velum down and forward
     • Pharyngopalantine
       • Pulls velum down and back

5. Nasal Cavities

   • a.k.a. Nasal Fossae
   • 2 chambers separated by nasal septum
     • Septum is cartilage at front, bone at back
   • Floor is hard palate
   • Nasal Conchae
     • 3 Structures
       • Superior
       • Middle
       • Inferior
     • Complex, large structures