Comparative Physiology of
Myoneural MechanismsTHE foregoing account of the process of neuromuscular transmission and its underlying mechanisms has been derived from
heterogeneous data obtained from several different preparations.
Yet the assembly of these data enables us to understand only
about the mechanism in a highly specialized and limited system,
the ordinary skeletal apparatus of vertebrates. Most of the
invertebrate phyla have not yet been examined fully, and some
have not been examined at all with modern techniques. In a
few cases, as in the coelenterates, which have attracted considerable attention, the new techniques unfortunately cannot
be applied, but a great deal has nevertheless been learned about
them from cleverly designed experiments using simple methods,
followed by exhaustive deductive analysis. Extensive deviations
from the vertebrate mechanism will undoubtedly be encountered
and yet certain aspects of the foregoing account may reasonably
be utilized in constructing a general picture. We may draw up
a list of broad principles and assume provisionally that they
have universal application. Already almost all the evidence
from the comparative field supports this assumption. If the
principles apply to all phyla, as they may, the task of the
comparative physiologist will be greatly simplified.
GENERAL PRINCIPLESThe apparently universal principles on which the phenomena
of neuromuscular transmission are based are as follows:
|1. ||Each muscle cell has a very thin, surface-boundary,
plasma membrane which possesses both general and special
|2. ||The electrical properties of the plasma membranes of all
the cells in a homogeneous muscle are similar.|
|3. ||When the cells are at rest an electrical potential|
Questia, a part of Gale, Cengage Learning. www.questia.com
Book title: Comparative Physiology of the Nervous Control of Muscular Contraction.
Contributors: Not available.
Place of publication: Cambridge.
Publication year: 1957.
Page number: 67.
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