Gonadotrophins released by pituitary gland are FSH (Follicle stimulating hormone) and LH (Luetinizing hormone). These hormones are released under the influence of Hypothalamic hormones. FSH is responsible for formation and growth of follicles while LH causes ovulation and formation of corpus luteum. Oxytocin is known as birth hormone. This hormone causes ejection of milk and also contraction of uterus during child birth. Oxytocin is released from posterior pituitary but secreted by Hypothalamic nuclei. After child birth the suckling of nipples cause release of oxytocin and thus milk is ejected but production of milk is done by prolactin hormone. Prolactin (PRL) is released by anterior pituitary and causes formation of milk by mammary glands. Thus Oxytocin and PRL are together responsible for lactation.