Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2005-1-28
pubmed:abstractText
The internal laryngeal muscles have evolved to subserve the highly specialized functions of airways protection, respiration, and phonation. Their contractile properties, histochemistry, biochemical properties, myosin heavy chain (MyHC) expression and their regulation by nerves and hormones are reviewed and compared with limb muscle fibres. Cricothyroid, the vocal cord tensor, is limb-like in MyHC composition and fibre type properties, while the vocal fold abductor and adductors are allotypically different, with capacity for expressing an isoform of MyHC that is kinetically faster than the fastest limb MyHC. In rats and rabbits the faster isoform is the extraocular (EO) MyHC, while in carnivores, it is the IIB MyHC. These adaptations enable the abductor and adductor muscles to remain always faster than the cricothyroid as the latter changes in speed during evolution to match changing metabolic and respiratory rates in relation to scaling with body mass. Such phylogenetic plasticity is vital to the airways protection and respiratory functions of these muscles. The posterior cricoarythenoid, the abductor muscle, is tonically driven during expiration, and consequently has a slower fibre type profile than the principal adductor, the thyroarythenoid. The human thyroarythenoid appears not to express EO or IIB MyHC significantly, but is unique in expressing the slow-tonic MyHC. The concepts of allotype and phylogenetic plasticity help to explain differences in fibre type between limb and laryngeal muscles and between homologous laryngeal muscles in different species. Laryngeal muscle fibres exhibit physiological plasticity as do limb muscles, being subject to neural and hormonal modulation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0001-6772
pubmed:author
pubmed:issnType
Print
pubmed:volume
183
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
133-49
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Laryngeal muscle fibre types.
pubmed:affiliation
Discipline of Physiology, Institute for Biomedical Research, Faculty of Medicine, School of Medical Sciences, The University of Sydney, NSW, Australia.
pubmed:publicationType
Journal Article, Review, Research Support, Non-U.S. Gov't