Results:Cartilage canals which grew into epiphyses from perichondrium or cruciate ligaments were found at 14 wk,increased at 22 wk and developed fully at 29 wk of gestation.

• 结果:胎儿8周时无软骨管,14周软骨管数目少,22周增多,29周最多,分支复杂,新生儿软骨管数目减少。软骨管除由动脉、静脉和毛细血管,还包含淋巴管。