人胎手指真皮乳头嵴形成的光镜和扫描电镜观察

用光镜和扫描电技术了２－１０月龄人胎手指端真皮乳头嵴的形成过程。结果证实：３个月龄时真皮表现出现了原始真皮嵴，５个月龄时每条原始真皮嵴开始分化形成两条同源的真嵴，６个月龄时每条真皮嵴又开始分化形成许多真皮乳头，并由真皮乳头组成真皮乳头嵴，以后随胎龄的增加真皮乳头嵴逐渐增大。汗腺导管于４月龄时出现于原始真皮嵴间沟内，阴着同源真皮嵴和真皮乳头嵴的形成，使汗腺导管位于两条非同源真皮乳头嵴间沟内，每条表面

STUDY ON THE FORMATION OF DERMAL PAPILLA RIDGE OF HUMAN FETAL FINGER BY LIGHT AND SCANNING ELECTRON MICROSCOPY

he process of finger corium ridge formation was studied in human fetus aged 2 10 months by light and scanning electron microscopy.The results showed that primordial corium ridges were present on the surface of the corium at the 3rd month and each of them devided into two homologous corium ridges from the 5th month.At the 6th month,each of the corium ridges differentiated into many dermal papillae and arranged as dermal papilla ridges and they became larger with development of the fetus.The duct of sweat gland appeared in the grooves between primordial corium ridge from the 4th month onwards and they located in the grooves between dermal papilla ridges those were non homologous with the forming of homologous corium ridges and dermal papilla ridges.Two nonhomologous dermal papilla ridges were wrapped up by each epidermis ridges.