Lectures on the sympathetic innervation of striated muscle by the late John Irvine Hunter : delivered at University College, London by G. Elliot Smith.

  • John Irvine Hunter
Date:
1925
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Licence: Public Domain Mark

Credit: Lectures on the sympathetic innervation of striated muscle by the late John Irvine Hunter : delivered at University College, London by G. Elliot Smith. Source: Wellcome Collection.

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    THE DUAL INNERVATION OF STRIATED MUSCLE. In his classical memoir on postural activity of muscle and nerve Sir Charles Sherrington makes the statement that: “ The existence in various invertebrata of muscles separ¬ ately differentiated for execution of movements and for maintenance of posture respectively seems without parallel in the skeletal musculature of vertebrates. In the latter, one and the same muscle is used for the two purposes, though some muscles are predominantly concerned with the one, some with the other function.” Discussing the same subject, the late Sir William Bayliss was frankly sceptical. Thus, in his Principles of General Physiology he says: “It is not easy to understand how two fibres of different function and different innervation could coalesce with retention by the combined cell of both kinds of innervation.” The chief aim of these lectures is to justify Bayliss’s attitude of scepticism by showing that no such coalescence does in fact occur, for the muscular tissues of vertebrates are at least as highly differentiated in structure and function as those of invertebrates. In his discussion of the sympathetic innervation of striated muscle that led to this expression, Bayliss admits that “ two kinds of function are performed by two separate kinds of muscle fibres, as in the auricle of the tortoise, or by separate muscles, as in the mollusc ” ; yet he gees on to express the commonly accepted view in these terms: “ But in other cases, as in the vertebrate bladder or in that of voluntary muscles, the same fibres undertake both functions, so far as can be made out.” I shall first give reasons for the conclusion that the same fibres do not undertake both functions. Tho evidence in support of this conclusion is provided (a) by tho appreciable structural differences in the two [4(3/25] 1