Fertilization in Human beings
Fertilization is internal in human beings
- This process occurs in the fallopian tube
- Ovum comes from ovary to Fallopian tube. Unfertilized egg remains alive for approx. 24 hours
- Sperms enter through vagina and reach the Fallopian tube. Sperm must fertilize the egg within the above time.
- Sperm enters the egg
- Fusion of nucleus of sperm & ovum is termed as Fertilization
- Fertilization leads to the formation of single-celled Zygote
- Zygote undergoes repeated divisions, and gets implanted in the uterus. This is now called as Embryo. Embryo in advanced stages of development is termed as Foetus.
- Uterus also prepares itself to receive the embryo. It thickens its walls. Embryo descends into uterus in 4-5 days from the day of fertilization.
- Embryo in the uterus receives nutrients from the mother’s body through the Umbilical cord which in turn is connected to the uterine wall of mother through Placenta. Placenta: is a structure formed by specialized tissues of fetus & uterine wall of mother.
- Nutrients enter through this cord, and wastes go out of the foetus body. Umbilical cord also has arteries & veins for exchange of oxygenated and deoxygenated blood.