Flexion and Extension : Studies Employing Muscles of the Shank in Amphibians


Tibialis anticus and peronaeus longus of the frog have been examined by optical and electron microscopy. Sodium and potassium concentrations of these muscles have been determined. Double myograms have been used to compare physiological and pharmacological properties of flexor and extensor and to demonstrate various patterns of convulsion and their modification by depressants. Contractures have been investigated in the isolated organ bath. Depolarizing agents have been used to compare the proportions of slow fibres in the gastrocnemius of frogs and toads. Tibialis anticus, a flexor, has been shown to be heterogenous, consisting of twitch and slow fibres, and peronaeus longus to be homogenous, containing only twitch fibres. The twitch fibres of the flexor are shown to be fast compared with the twitch fibres of the extensor and their resting potentials, as deduced from potassium concentrations, are found to differ, Evidence is collated to evince the principle that a flexor is heterogenous to effect the functions of rapid withdrawal and of maintaining that withdrawal, whereas an extensor is homogenous since it merely exerts a thrust. Analogies between amphibian and mammalian muscle fibres are discussed.

Divisions: College of Health & Life Sciences > Aston Pharmacy School
Additional Information: Copyright © Bennett, 1973. J.M. Bennett asserts their moral right to be identified as the author of this thesis. This copy of the thesis has been supplied on condition that anyone who consults it is understood to recognise that its copyright rests with its author and that no quotation from the thesis and no information derived from it may be published without appropriate permission or acknowledgement. If you have discovered material in Aston Publications Explorer which is unlawful e.g. breaches copyright, (either yours or that of a third party) or any other law, including but not limited to those relating to patent, trademark, confidentiality, data protection, obscenity, defamation, libel, then please read our Takedown Policy and contact the service immediately.
Institution: Aston University
Uncontrolled Keywords: Flexion and extension,muscles of the shank amphibians
Last Modified: 28 Jun 2024 07:05
Date Deposited: 18 Jan 2011 10:41
Completed Date: 1973
Authors: Bennett, J.M.

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