pharyngeal oral physiology

pharyngeal-oral functions

• oral airway opening

• swallowing

• sound generation and filtering

sound generation (and what type of sounds)

• creation of an acoustic source within the larynx and/or oral cavity

• transient and turbulent sounds

transient sounds

oral airstream is momentarily interrupted and then released (stop-plosive)

turbulent sounds

air is forced through a narrow constriction in oral cavity (fricative, affricate)

sound filtering

shaping of the source sound generated in the larynx and/or oral cavity

how are source features modified?

source features are modified by the size and shape of the pharynx and oral cavity (vocal tract)

acoustic output

combination of the sound source and the features of the vocal tract filter

length changes in oral vestibule

• upper lip

• lower lip

• mandible

length change in oral cavity

• tongue

• mandible

length change in pharyngeal cavity

• velum

• larynx

cross sectional change in oral vestibule

• upper lip

• lower lip

• mandible

• cheeks

• tongue

cross sectional change in oral cavity

• tongue

• mandible

cross sectional change in pharyngeal cavity

• tongue

• epiglottis

• posterior pharyngeal wall

• lateral pharyngeal walls

what pharyngeal muscles changes the cross sectional area of the pharyngeal tube?

• decreased by superior, middle, inferior constrictors

• increased by stylopharyngeus

what pharyngeal muscles changes the length of the pharyngeal tube?

• decreased by stylopharyngeus

what mandibular/labial muscles changes the cross sectional area and length of the oral tube?

• decreased by mandibular elevators and labial retractors

• increased by mandibular depressors and labial protrudors

what lingual muscles changes the cross sectional area of the oral tube?

• decreased by lingual elevators

• increased by lingual depressors 

what lingual muscles changes the length of the oral tube?

• decreased by lingual protruders

• increased by lingual retractors

electropalatography (EPG)

• measures tongue-palate contact in real time during speech (does not measure movement)

• requires an artificial palate with 60-100 embedded electrodes

articulography

• fleshpoint tracking

  • attach tiny pellets or transmitters to the articulators and track their positions over time

videofluoroscopy 

• the diagnostic standard for swallowing 

• produces a 2D image at a rate of 30 frames (images) per second 

videofluoroscopy advantages

• images all structures involved in speaking, chewing, and swallowing

videofluoroscopy disadvantages

• X-ray radiation

• only sagittal or A-P views

• no direct access to numerical data

magnetic resonance imaging (MRI)

• acquires 2D or volumetric (3D) image sets

• images can be collected in any of the 3 imaging planes as well as their oblique planes

• relatively high quality images and safe

what can be used to image the pharyngeal-oral lumen (vocal tract)?

X-ray CT or MRI can be used to construct 3D images of the vocal tract