With aid of diagrams, describe fertilization, development of foetus and birth process in human beings

a) Fertilization Process Sperms produced by testis which travel through the epididymis, sperm duct and then urethra and they are deposited in the vagina of the female by the penis during coitus. Ova (eggs) in woman are produced at intervals by the ovaries. Only one ovum is produced in turn by every ovary. This cycle lasts 28 days with every cycle the uterus undergoes major cyclical changes. The eggs are released onto the oviduct and then they move down to the uterus and to the outside after passage through vagina if not fertilized. Sperms deposited swim up the cervix into the uterus and oviduct where fertilization takes place.

b) Development of Foetus After fertilization in the oviduct, a zygote is formed by fusion of male and female nuclei. The zygote then moves down to the uterus and attaches to the walls of the uterine lining. The zygote develops into a foetus which is connected to the placenta (baby container) by an umbilical cord. Through this, food is provided to the foetus by the mother and waste products are removed from the other end.

NB. By the end of 40 weeks all organs of the foetus have developed. The foetus is suspended in a fluid filled sac. It turns around so that the head is lying next to cervix. Birth is started by hard (vigorous) contraction of the uterus muscles which expels the foetus out of the uterus via the vagina (parturition).
c) Process of Birth During pregnancy the breasts of woman increase in size and by the time of birth (parturition) are capable of producing milk for the breast milk for the nourishment of the baby. All nutritional requirements of the baby for the first months are met by the breast milk. The birth of human foetus is accompanied by loud cry and this reflex initiates spontaneous breathing by the lungs.

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Mutiso answered the question on October 7, 2018 at 11:44