Copin H, Bourdelat D, Dupont C, Barbet J P
Laboratoire d'Histologie-Embryologie-Cytogénétique, Faculté de Médecine Lariboisière Saint Louis, Paris, France.
Morphologie. 1999 Sep;83(262):23-5.
The development of the foetal anorectal continence is related to the appearance of the anatomical components of the sphincter. The present study has been carried out in order to analyse the development of the smooth and striated components of the anorectal sphincter, in a series of 7 embryo and foetuses aged from 10 to 40 weeks of pregnancy. Our results indicate that the external sphincter, the puborectalis muscle and the internal sphincter are present before 24 weeks, although they obviously play variable roles in the establishment of the foetal continence. The internal sphincter becomes quantitatively important after 14 weeks, and is likely to be responsible for the establishment of the initial continence. The growth of the striated components during the foetal period corresponds to the maturation of the innervation and of the voluntary mechanisms controlling continence. Intrication of smooth and striated muscle components in the external sphincter starts after the end of the embryonic period. All the anatomical components of the anorectal sphincter are present at birth.
胎儿肛门直肠节制功能的发育与括约肌解剖结构的出现有关。本研究旨在分析一系列妊娠10至40周的7例胚胎和胎儿肛门直肠括约肌平滑肌和横纹肌成分的发育情况。我们的结果表明，外括约肌、耻骨直肠肌和内括约肌在24周前就已存在，尽管它们在胎儿节制功能的建立中显然发挥着不同的作用。内括约肌在14周后在数量上变得重要，并且可能负责初始节制功能的建立。胎儿期横纹肌成分的生长与控制节制功能的神经支配和自主机制的成熟相对应。外括约肌中平滑肌和横纹肌成分的交织在胚胎期结束后开始。肛门直肠括约肌的所有解剖成分在出生时均已存在。
