Müller F, O'Rahilly R, Benson D R
Carnegie Laboratories of Embryology, California Primate Research Centre, Davis.
J Anat. 1986 Dec;149:157-69.
An anomalous (butterfly) eleventh thoracic vertebra in a fetus of 63 mm greatest length is described and graphic reconstructions (together with normal controls) are provided. The cartilaginous hemicentra are separated by disc-like material. Cartilaginous bars to adjacent vertebrae are present. The neural arch is complete. The notochord is not duplicated. Only one comparable case in the embryonic period has been described previously. After a discussion of cleft vertebrae in the human and in experimental animals, a developmental timetable of the appearance of several vertebral anomalies is provided. The sensitive period for butterfly vertebrae, depending on the mode of origin, seems to be 3-6 postovulatory weeks. More severe anomalies, such as the split notochord syndrome, appear earlier. It is concluded that most of the vertebral anomalies discussed arise during the embryonic period proper, although the timing of a few, such as spina bifida occulta, extends into the early fetal period.
描述了一例最大长度为63毫米胎儿的异常（蝴蝶状）第十一胸椎，并提供了图形重建（以及正常对照）。软骨半椎体被盘状物质分隔。存在与相邻椎体相连的软骨条。神经弓完整。脊索未重复。此前仅描述过一例胚胎期的类似病例。在讨论了人类和实验动物的椎体裂后，给出了几种椎体异常出现的发育时间表。蝴蝶椎的敏感期，取决于起源方式，似乎是排卵后3 - 6周。更严重的异常，如脊索分裂综合征，出现得更早。结论是，尽管少数异常（如隐性脊柱裂）的发生时间会延伸到胎儿早期，但所讨论的大多数椎体异常都发生在胚胎期本身。
