PARTURITION AND LACTATION:
· The period of pregnancy is called gestation period. (9 months).
· Ejection or expulsion or delivery of foetus is called parturition.
· Parturition is due to vigorous contraction of uterine Myometrium.
· The signal of parturition is originated from the fully developed foetus and the placenta which induces mild contraction of uterus called foetal ejection reflex.
· Fetal ejection reflex triggers the release of Oxytocin from pituitary.
· Oxytocin induces stronger contraction of uterine endometrium.
· Stimulatory reflex continues stronger contraction leads to expulsion.
· After delivery the placenta is also expelled out of the uterus.
· The mammary gland of the female more differentiated during pregnancy,
· Mammary gland starts producing milk towards the end of the pregnancy.
· Process of milk production in mammary gland is called lactation.
· Milk produced during initial days of lactation is called colostrum.
· Colostrum contains several antibodies which provide immunity to the new born baby.
Humans reproduce sexually by the union of male and female sex cells.Reproductive system of male and female are different, they are structured to function together to achieve internal fertilization.
Spermatogenesis is the process of formation of sperm from the germ cell in the testes. Oogenesis is the formation of mature female gamete or ovum. Reproductive cycle of female primates is called menstrual cycle.