Section 8 Flashcards
Name the muscles of the velum including their function and what innervates them.
Levator Veli Palatini (CN X) → elevates velum
Tensor Veli Palatini (CN V) → assists levator veli palatini, tenses velum for support for
pharyngeal elevation during swallow, opens Eustachian tube for pressure equalization between tympanic cavity and outside air
Palatoglossus (CN X) → elevates posterior tongue, depresses velum (downward and forward)
Palatopharyngeus (CN X) → depresses velum
Uvulus (CN X) → shortens uvula, adds bulk and stiffness to velum
What are the methods of proper VP closure?
- Velar elevation
- Inward movement of lateral pharyngeal walls
- Combined velar elevation + inward movement of lateral pharyngeal walls
- Velar elevation + inward movement of lateral pharyngeal walls + movement of posterior pharyngeal walls
What are the passive forces of velopharyngeal movement?
Natural recoil of muscles, cartilages, and connective tissues
Surface tension between structures in apposition
Pull of gravity → have to contract muscles to raise velum but not to lower
Aeromechanical forces within the upper airway (throat, mouth, nose) → sneeze
Describe normal VP function.
VP raises/closes for oral sounds, especially stops (high pressure)
VP open for nasal sounds
VP closure = swallowing (oral phase)
What are some examples of abnormal velopharyngeal function?
Hypernasality → usually caused by VPI, palatal fistula, misarticulation if phoneme-specific (Speech therapy is phoneme specific)
Hyponasality → obstruction in nasopharynx or nasal cavity
Mixed Nasality → combo of VPI and significant nasal airway blockage
Cul-de-sac resonance → obstruction at the exit of a cavity of oral tract (oral, nasal, pharyngeal)
Compare and contrast CP insufficiency, incompetency, and misleading.
Insufficiency: structural
- Etiologies include submucous/cleft palate, cranial base anomalies, post adenoidectomy, Palatopharyngeus disproportion, Ablative palatal lesions
Incompetency: neurogenic, neurophysiological, and be congenital or acquired and associated with motor control (dysarthria) or motor programming (apraxia)
Mislearning: Phoneme-specific nasal emission, persisting post-op nasal emission (with adequate closure ability), compensatory misarticulations, deafness/hearing impairment
What is normal resonance?
The result of the transfer of sound produced by vocal folds through vocal
tract comprised of pharynx, oral cavity, and nasal cavity. Vocal tract filters this sound, selectively enhancing harmonics based on size and/or shape of vocal tract. Perceived resonance is the
result of this filtered tone
Achieved through an appropriate balance of oral and nasal sound energy, based on the intended speech sound
What is hypernasality?
Occurs when there is sound energy in nasal cavity during production of (voiced) oral phonemes
Particularly perceptible on vowel sounds, and on oral consonants
Often accompanied by nasal air emission during consonant production
Lack of adequate intra-oral air pressure for consonant production commonly results in development of compensatory articulatory phonemes
Often caused by structural/neurophysiological disorders
What is hyponasality?
Reduction of nasal resonance during speech due to blockage in nasopharynx or in entrance to nasal cavity
Denasality = complete occlusion of nasal cavity during speech
Particularly effects production of nasal consonants (/m/, /n/, /ng/) → can sound similar to their oral cognates (/b/, /d/, /g/)
What is mixed resonance?
When speech has characteristics of both hypernasality + hyponasality
The hypernasality occurs on oral sounds and hyponasality occurs on nasal sounds
What is cul-de-sac resonance?
Occurs when sound resonates in a cavity (oral, nasal, pharyngeal) but is “trapped” and cannot exit because of obstruction
Oral cul-de-sac resonance: sounds like mumbling or speaking without opening mouth
Pharyngeal cul-de-sac resonance: “potato-in-mouth” speech → most common one
What are some causes of hypernasality?
Usually caused by structural or neurophysiological disorder
Velopharyngeal dysfunction
Genetics → 22q11.2 deletion syndrome (CLP), Treacher Collins syndrome
Large oronasal fistula following cleft palate repair
What are some causes of hyponasality?
Caused by obstruction in nasopharynx/nasal cavity
- Adenoid hypertrophy
- Swelling of nasal passages 2º to allergic rhinitis
- Common cold
- Deviated septum
- Choanal atresia (= congenital blockage of opening into nasopharynx from nasal fossa)
- Stenotic naris
- Midface deficiency
Can also be caused by apraxia → inconsistent, abnormal VP closure on nasal phonemes
What are some causes of mixed resonance?
Combo of VPI and any form of nasopharyngeal obstruction
Can also be caused by apraxia → motor sequencing problems can affect timing of upward/downward movement of velum, resulting in inappropriate closure/opening of velum
What are some causes of cul-de-sac resonance?
Oral: microstomia
Nasal: combo of VPI + blockage at anterior of nose
- Most commonly found in individuals with history of cleft palate with VPI, and stenotic nares or deviated septum
Pharyngeal: caused by large tonsils that block sound from entering oral cavity during speech
What are compensatory articulation errors?
Incorrect articulation placement in response to abnormal structure
Glottal stops, pharyngeal plosives, pharyngeal fricatives, pharyngeal affricates, posterior nasal fricatives as substitutions for oral pressure sounds
These compensatory productions can often be coarticulated with correct oral sounds
What are obligatory articulation errors?
Characterized by abnormal acoustic production due to structural abnormality, despite normal articulatory placement
Some oral phonemes will sound like their nasal cognates (b → m, d → n, g → ng)
Hypernasality +nasal air emission with normal articulation
Because obligatory articulation is caused by abnormal structure and not abnormal function, they cannot be correct with speech therapy