Preliminary note on the anatomy of the umbilical cord / by Lawson Tait.

  • Tait, Lawson, 1845-1899.
Date:
1876
Catalogue details

Licence: Public Domain Mark

Credit: Preliminary note on the anatomy of the umbilical cord / by Lawson Tait. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    Preliminary Note ou the Anatomy of the Umbilical Cord*. By Lawson Tait, F.R.C.S. &c. [Plates 11, 12, 13, 14.] I. Its external Form and Method of O-rowth. The peculiar twisted appearance of the human umbilical cord has re- ceived much attention from anatomists, and has been the subject of much ingenious speculation. According to Velpeau (‘Embryologie’) the torsion begins as early as the seventh or eighth week, whilst Burdach has not observed it earlier than the tenth. I have repeatedly seen foetuses, apparently of the twelfth and thirteenth week, in which no appearance of twisting was observable in the cord, though one of the most perfectly twisted cords in my possession belongs to a foetus of certainly not more than thirteen weeks’ development. Velpeau attributes the twisting simply to the rotation of the foetus. Schroeder Van der Kolk supposes that the blood flowing in the arteries exerts a backstroke influence on the pelvis of the swimming foetus, thus determining its revolution in one direction or the other, as the arteries are to be found to the right or left of the vein. In order to dismiss this view we have only to recollect that the umbilicus could not in any way become a fixed axis, and that the mechanical arrangement of the heart, in the non-separation of its streams, would yield but a very weak im- pulse until very late in pregnancy. The revolution of the foetus is not known to occur, though its occurrence is probable. Such revolution occurs in the spawn of the frog as early as the first segmentation of the black sphere; but then it is evidently the result of the necessity there is for an equal exposure of all parts of the embryo to the action of light and heat, just as the germinal spot is always uppermost in the bird’s egg. No such necessity exists in the persistently included mammalian ovum, and the revolution of the foetus cannot be accepted. If it did occur it is highly improbable that the revolutions could number only from four to eighteen, these being the ranges I have noticed in a large number of fully developed cords. Another objection to Schroeder’s hypothesis is that, as a matter of fact, the arteries leave the omphalic ring nearly always below the vein and symmetrically arranged in relation to it. Their passage to one or other side of it is seldom apparent till the ex- ternal dermal ring has been reached. Also I have seen the first revolu- tion of the arteries pass from right to left, after which they suddenly bent on themselves and passed up the cord in an irregularly straight course, whilst the vein maintained the normal spiral. Further I have seen the arteries reverse their course about the middle of the cord’thoimh the vein maintained the uniform spiral. Sir .Tames Simpson (‘Edinburgh Medical Journal,’July 1859) was of * See Proceedings, vol. xxiii. p. 493 __