Actomyosin ATPase activity of human laryngeal muscles.
The muscles from seven human larynxes removed by laryngectomy have been examined for actomyosin ATPase by histochemical methods. The various muscles contained a mixture of ATPase low (type I) and ATPase high (type II) muscle fibres. The thyreoarytenoid muscle had the highest proportion of type II fibres (65%) and the posterior cricoarytenoid muscle had the highest proportion of type I fibres (67%). The other laryngeal muscles had intermediate valves. All human laryngeal muscles had a higher percetage of type I fibres than the corresponding muscles in animals so far examined, a finding which may be related to the development of speech.
D000205:Actomyosin / Q000378:metabolism*; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D006801:Humans; D007822:Laryngeal Neoplasms / Q000201:enzymology; D007830:Larynx / Q000201:enzymology*; D008297:Male; D009132:Muscles / Q000201:enzymology*
D000205:Actomyosin; D000251:Adenosine Triphosphatases