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人类受精过程可分为男女生殖细胞的发育和成熟。精子在女性生殖道内获能,至精原核与卵原核的染色体结合而成为一受精卵为止。一、卵细胞的发育和成熟女性胚胎在第5周生殖细胞移到生殖嵴,形成卵原细胞,并迅速分裂成初级卵母细胞。在胎儿5个月时已增殖到600～700万个,到足月新生儿出生时约有10～50万个初级卵母细胞,以后不再增添。(一)始基卵泡每一个初级卵母细胞周围有一层原始的颗粒细胞,其外层为基膜,形成一个始基卵泡。这许多始基卵泡在妇女一生中不断成批成长,但99%以上均在开始发育不久,即相继衰萎消失,称为卵泡闭锁。妇女到青春期和生育期,一生才有数百个卵泡完全发育成熟,排出成熟的卵细胞,这些成熟的卵细胞只有几个能受精着床发育成胚胎。其发育过程如下:
Human fertilization process can be divided into male and female germ cells development and maturation. Sperm in the female reproductive tract to be able to sperm and sperm nuclear progenitor chromosomes combined into a fertilized egg up. First, the development and maturation of egg cells Female germ cells in the fifth week moved to the genital ridge, the formation of oogonium, and rapidly split into primary oocytes. In the fetus 5 months has been multiplied to 600 to 700 million, to full-term newborn babies born about 10 to 500000 primary oocytes, no longer increase. (A) primordial follicles around each primary oocyte has a layer of primitive granulosa cells, the outer layer of the basement membrane, the formation of a primordial follicles. Many primordial follicles in the women’s life continue to grow in batches, but more than 99% are beginning to develop soon, which have faded disappear, known as follicular atresia. Women to adolescence and growth period, only a lifetime full of hundreds of follicles fully mature, the discharge of mature egg cells, these mature egg cells can fertilize the implantation into only a few embryos. Its development process is as follows: