Specializations for Excitation-Contraction Coupling in the Podial Retractor Cells of the Starfish Stylasterias forreri
Date
1981
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Springer-Verlag
Abstract
Ultrastructural examination of the podium of the asteroid
echinoderm Stylasterias forreri has revealed that cells of the coelomic
epithelium and cells of the retractor muscle should be considered as components
of a single epithelium. The podial retractor cells are, therefore, myoepithelial in
nature. This report concentrates on those ultrastructural features of the
retractor cells that are most likely involved with excitation-contraction
coupling. The spatial arrangement of the sarcoplasmic reticulum, the couplings
between the sarcoplasmic reticulum and sarcolemma, and an intramembranous
specialization of the sarcolemma are documented and discussed. Current
concepts regarding the innervation of the retractor cells of the podium and the
protractor cells of the ampulla are reviewed; and specific proposals for further
investigation of podial innervation are outlined.
Description
Keywords
Biology
Citation
Michael J. Cavey and Richard L. Wood "Specializations for Excitation-Contraction Coupling in the Podial Retractor Cells of the Starfish Stylasterias forreri" Cell Tissue Res (1981) 218:475-485