Bragulla H
Institut für Veterinäranatomie, Freien Universität Berlin.
Anat Histol Embryol. 1991 Mar;20(1):66-74. doi: 10.1111/j.1439-0264.1991.tb00293.x.
The term Eponychium is used to describe the deciduous hoof capsule in veterinary-medical and embryological literature. In other aspects of veterinary medicine, the term is generally reserved for the perioplic corium of the permanent hoof. In order to clarify this double usage, the structure and origin of the hoof epidermis from 10 equine fetus at different stages of development and 4 newborn foals were investigated and described using light microscopical techniques. Epidermal tubules and lamellae are already present in the non-cornified fetal hoof epidermis. These structures, along with the formation of a white line, allow this epidermis to be divided into the same segments as are commonly used when referring to the permanent hoof. The greatest part of the deciduous hoof epidermis consists of the sole and frog, with significant portions forming in the coronary corium and that of the hoof wall as well. The perioplic corium only makes up insignificant portions of the fetal hoof capsule, however. Between the second half of the gestation period and birth, this deciduous (primary) hoof capsule is continually being replaced from below by newly-forming, cornified permanent hoof capsule. On the basis of its structure and origin, we therefore suggest that the term "deciduous hoof capsule (Capsula ungulae decidua)" be used as a replacement for the word "Eponychium" when referring to the primary hoof epidermis.
在兽医医学和胚胎学文献中，术语“蹄冠”用于描述脱落的蹄角质壳。在兽医学的其他方面，该术语通常用于指永久蹄的蹄冠真皮。为了阐明这种双重用法，利用光学显微镜技术对10个处于不同发育阶段的马胎儿和4只新生马驹的蹄表皮结构和起源进行了研究和描述。在未角质化的胎儿蹄表皮中已经存在表皮小管和板层。这些结构，连同白线的形成，使得该表皮能够被划分为与提及永久蹄时常用的相同部分。脱落蹄表皮的最大部分由蹄底和蹄叉组成，在冠状真皮和蹄壁真皮中也有相当一部分形成。然而，蹄冠真皮在胎儿蹄角质壳中仅占微不足道的部分。在妊娠期后半段至出生之间，这种脱落的（初级）蹄角质壳不断地从下方被新形成的、角质化的永久蹄角质壳所取代。因此，基于其结构和起源，我们建议在提及初级蹄表皮时，使用术语“脱落蹄角质壳（Capsula ungulae decidua）”来替代“蹄冠”一词。
