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

  • Lawson Tait
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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    has no relation whatever to the development of the child), the arteries are to be seen on the outside of the imperfect helix, and this greater length has to be accommodated by twistings and reversions. But even in such a cord sections are to be seen where the spiral becomes complete, and then the arteries take their normal place within the helix. Injection of one or both arteries by plaster, with subsequent drying, does not produce a spiral even in cases where the cord has shown a very marked spiral when the vein has been previously distended with water. When the spiral is faintly marked but the cord long, and the arteries not very much, if at all, longer than the vein, the spiral will be found always at the end near the foetus. Thus in one specimen, which is very typical of this class, there are three well-marked helices occupying the six inches of the cord at the foetal end. One artery was successfully injected, and it is seen to occupy an almost straight course in the middle of the helices, the uninjected artery accompanying it closely, w’hilst further on they are both seen to follow, with only one reversion or doubling, the almost straight course of the vein. This last fact makes it very evident that the growth of the spiral is directed by some mechanism at the foetal end of the cord, and not by any hypothetical revolutions of the foetus. From the appearances of some cords it would also seem as if the spiral growth of the cord became interrupted for a short time, or even reversed, and theu that it resumed its original direction. In the first and fourth volumes of the ‘ Encyclopaedia of Anatomy ’ some interesting quotations are given by Vrolik and Mr. J. Hart. Vrolik gives some cases where the vessels ran from the foetus to the placenta separately, and not twisted in a cord. He also mentions that extreme shortness of the cord is generally accompanied by ectopia of the abdominal viscera, indicating an arrest of development at an early period of embryogenesis. Budolphi states that the umbilical vein is persistently double in the Quadrumana of the new w-orld; but I cannot anywhere find a statement as to whether, in such a case, the cord is twisted or not. I think we may conclude from some of these facts that both the growth of the cord and its spiral direction are due to some mechanism at the omphalic ring, and that probably that mechanism is in a most im- mediate relation to the umbilical vein. Eurther, I think it certain that the greater part of the spiral, and the closest coils of the spiral, are formed during the later months, or even weeks, of gestation. Thus in cords which are deficient in the spiral it is always most marked near the fcetus ; and in one which I have already alluded to as the most perfectly spiral cord I have seen, the helices w?ere complete in an inch and an eighth near the child, whilst they gradually opened out towards the placenta, so that the last vras nearly three inches
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