Microscopic anatomy of the thin-walled vessels leaving the heart of the lobster Homarus americanus: anterior lateral arteries
Date
2006
Journal Title
Journal ISSN
Volume Title
Publisher
Blackwell Publishing, Inc.
Abstract
The anterior lateral arteries are paired vessels leaving the anterior end of the lobster
(Homarus americanus) heart and proceeding to the antennae and eyestalks, the stomach and
hepatopancreas, the gonads, and the thoracic and branchial muscles. These vessels have a
trilaminar organization, consisting of a tunica interna with elastic fibrils, a tunica intermedia
represented by a bilayered cell mass, and a tunica externa with collagen fibrils. In the tunica
intermedia, cells flanking the tunica interna (light cells) show less affinity for basic dyes and
electron stains than those flanking the tunica externa (dark cells). Each light cell exhibits an
irregularly shaped stress fiber (a bundle of closely packed microfilaments) in the region adjoining
the tunica interna. Collectively, these bundles have a circumferential or slightly oblique
orientation relative to the lumen of the vessel. The role of the stress fibers is unresolved.
If they are static structures, they might contribute to the non-linear elasticity shown by lobster
arteries. If they generate force, and small bundles of microfilaments do diverge from the stress
fibers to enter filamentous mats applied to the plasmalemmata, a coordinated contraction of
the cells might reduce the luminal diameter and, thus, retard the flow of hemolymph. Coordination
of contraction would have to occur in the absence of nerves and without the benefit
of communicating (gap) junctions between the light and dark cells.
Description
Keywords
Biology
Citation
Chan, K. S., Cavey, M. J., Wilkens, J. L. 2006 "Microscopic anatomy of the thin-walled vessels leaving the heart of the lobster Homarus americanus: anterior lateral arteries" Invertebrate Biology 125: 76–88