Zoology - Chemical Coordination and Integration Question with Solution | TestHub

The secretion of the posterior lobe of pituitary is known as pituitrin and it contains two hormones. (i) Oxytocin or pitocin. (ii) Antidiuretic hormone (ADH) or vasopressin. The posterior lobe of the pituitary gland does not secrete any hormone. Its hormones are secreted in the hypothalamus. Oxytocin (OT) promotes contraction of the uterine muscle and contraction of the myoepithelial cells of the lactating breast, squeezing milk into the large ducts behind the nipple. In late pregnancy the uterus becomes very sensitive to oxytocin. The amount secreted is increased just before and during labour and by sucking of the baby. Because of its role, oxytocin is called "birth hormone" and "milk ejecting hormone."