Department of Surgery, Capital Institute of Pediatrics affiliated Children Hospital, Beijing, China.
Department of Anatomy, Wuxi School of Medicine, Jiangnan University, Wuxi, China.
Fetal Pediatr Pathol. 2022 Dec;41(6):919-928. doi: 10.1080/15513815.2021.2009943. Epub 2021 Dec 2.
Relatively little is known about allantois and urachal development in early humans. Serial sagittal histological sections from eight human embryos and fetuses were examined to determine allantois development. At gestational age 6-7 weeks, the primitive allantois consists of an enlarged tube located between the umbilical cord and abdominal cavity, whereas the urachus is not yet developed. At 8 weeks, the allantois gradually withdraws from the distal to the proximal end of the umbilical cord, and both the proximal allantois and the rectum (hindgut) start to develop into the cloaca. At 10 weeks, the allantois was located mostly in the abdominal cavity. The urachus forms from the distal end of the allantois and develops into a closed fibrous cord between the base of the urinary bladder and the umbilicus. The urogenital sinus forms from the proximal end of the allantois.
关于人类早期的尿囊和脐尿管发育，人们知之甚少。本研究通过对 8 个人类胚胎和胎儿的连续矢状组织切片进行检查，以确定尿囊的发育情况。在妊娠 6-7 周时，原始尿囊由一个位于脐带和腹腔之间的扩大管组成，而脐尿管尚未发育。在 8 周时，尿囊逐渐从脐带的远端向近端退缩，近端尿囊和直肠（后肠）开始发育形成泄殖腔。在 10 周时，尿囊主要位于腹腔内。脐尿管从尿囊的远端形成，并在膀胱底部和脐之间发育成一条封闭的纤维索。尿生殖窦从尿囊的近端形成。
