Milk-ejection reflex |Role of Oxytocin

Oxytocin that is  responsible for this reflex. Now lets discuss about this reflex in detail oxytocin is secreted from hypothalamus via para-ventricular and supra-optic nucleus. Paraventricular nucleus is the major site for production of oxytocin where as supra-optic nucleus also produces it but in small quantity and from there it goes to posterior pituitary for storage via hypothalamus-hypophyseal tract system.Mammary gland has many touch receptors mainly around nipples. when the baby suckles the nipple, somatic afferent impulses are sent to spinal cord and via spinal cord,impulses are sent to hypothalamus to supra-optic nucleus and para-ventricular nucleus.From there the the impulse is sent to posterior pituitary via hypothalamus-hypophyseal tract.It stimulates release of oxytocin that is stored in posterior pituitary.The released oxytocin have its action on myo-epithelial cells of duct  wall of mammary gland which leads to its contraction and eventually release of milk known as milk ejection reflex.