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Updated: Jun 23, 2026

Minimally Invasive Murine Laryngoscopy for Close-Up Imaging of Laryngeal Motion During Breathing and Swallowing
Published on: December 1, 2023
Pharyngeal muscle contraction modifies peri-pharyngeal tissue pressure in rabbits
Kristina Kairaitis1, Manisha Verma, Victoria Fish
1Ludwig Engel Centre for Respiratory Research, Westmead Millennium Institute, Australia. kristina_kairaitis@wmi.usyd.edu.au
Abstract:
We examined the influence of pharyngeal dilator muscle activity on upper airway extraluminal tissue pressure (ETP) distribution and upper airway patency. We studied seven anaesthetised, supine, spontaneously breathing NZ white rabbits. ETP was measured via pressure transducer tipped catheters in lateral (ETP(lat)) and anterior (ETP(ant)) pharyngeal wall tissues. Airflow (V) and tracheal pressure (P) were monitored and upper airway resistance (RUA) calculated. Genioglossus (GG) or bilateral sternohyoid (SH) muscles were electrically stimulated. Tongue protrusion (TP) during GG stimulation was measured. With GG stimulation, RUA decreased to 57.8+/-10.9% (mean+/-S.E.M.) of baseline and TP increased to 4.8+/-0.5mm (both p<0.05), but ETP(lat) (2.6+/-1.5 cm H(2)O) and ETP(ant) (1.4+/-0.8 cm H(2)O) were unchanged. SH stimulation reduced RUA to 53.6+/-6.8%, and ETP(lat) fell by 1.0+/-0.4 cm H(2)O (both p<0.05). ETP(ant) was unchanged. GG muscle contraction decreased RUA without altering ETP, whereas SH contraction altered RUA and ETP(lat), but not ETP(ant). Contraction of the upper airway dilator muscles results in improvements in upper airway patency associated with changes in peri-pharyngeal tissue pressure.
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