Lactogenic hormone or prolactin activate growth of breast lectogenic hormone or during pregnancy and secretion of mammary gland after birth. It is secreted by anterior lobe of pituitary gland. Oxytocin is secreted by posterior lobe of pituitary glands which promotes contraction of myoepithelial cells of the lactating breast which help squeezing of milk into large ducts behind nipples. Its amount is increased just before and during labour pain and by sucking of the boby. Therefore it is also known as birth hormone and milk ejecting hormone.