Reproduction is a complex process executed by the male and female reproductive organs. The reproductive organs are situated both outside and inside the body, thus being termed outer and inner reproductive organs respectively. The reproductive glands or gonads (ovaries and testis) are organs with a double function:
- production of special reproductive cells (gametes), i.e. eggs in the woman and spermatozoa in the man, and
- secretion of hormones with various regulatory actions on the organism, especially on the reproductive system.
The union of the spermatozoon and the egg will give rise to the embryo, which will develop in the womb and will result in the birth of a child.
The semen is deposited in the vagina during sexual intercourse. After its liquefaction a large number of spermatozoa pass through the outer opening of the cervix and progress through the cervix towards the uterus. From there, they move towards the fallopian tubes. The fertilization of the recently ovulated egg takes place in the fallopian tube. Following 4-5 days inside the tubes, the developing fertilized egg (zygote) is transported to the uterine cavity as a blastocyst and implants in the endometrium, before gestation begins.