And these nerve cells generate action, potential electrical signals and the electrical signals is carried to the hypothalamus of the brain of that mother. And what the hypothalamus does is it stimulates the posterior pituitary gland to release a hormone known as oxytocin. And what oxytocin does is it travels. Via the blood system and eventually reaches the muscle layer of this particular diagram. So when the muscle layer receives the oxytocin, what the oxytocin does is it stimulates the muscle layer to actually contract. And by contracting what the muscle layer does is it forces that milk.