Histochemical and morphometric properties of muscles of the upper airway of goats.
This study investigated the histochemical and morphometric properties of fibres in laryngeal, hyoid, tongue and pharyngeal muscles which contribute in maintaining patency of the upper airway. Muscle specimens from adult female goats were stained for nicotinamide adenine dinucleotide dehydrogenase-tetrazolium reductase and myosin adenosine triphosphatase activities, and the composition and size of the fibre types determined. These muscles contained types 1, 2A, 2B and 2C fibres with type 2 fibres predominating and the fibres possessed oxidative enzyme activity suggesting fast contraction speed and yet moderate resistance to fatigue. Abductor laryngeal muscles contained more type 1 fibres than the adductors. Among pharyngeal muscles fibre size and type 1 fibre composition increased progressively from the hyopharyngeus caudally. Upper airway muscles contained relatively small fibres (range of mean diameter: 25.7 to 46.1 microns) with the pharyngeal and lingualis proprius muscles containing the smallest fibres. These properties might influence the response of upper airway muscles to neuromuscular blocking drugs.
Ibebunjo
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Department of Clinical Veterinary Medicine, University of Cambridge.
D000818:Animals; D005260:Female; D006041:Goats / Q000033:anatomy & histology*; D007821:Laryngeal Muscles / Q000033:anatomy & histology* / Q000166:cytology; D009218:Myosins / Q000032:analysis; D009246:NADH Tetrazolium Reductase / Q000032:analysis; D010609:Pharyngeal Muscles / Q000033:anatomy & histology* / Q000166:cytology; D012132:Respiratory Muscles / Q000033:anatomy & histology* / Q000166:cytology / Q000201:enzymology; D014059:Tongue / Q000033:anatomy & histology* / Q000166:cytology
D009246:NADH Tetrazolium Reductase; D009218:Myosins