And what these two hormones do is they stimulate the lobules of granular tissue and the ducts to actually increase in size and this ultimately increases the size of the breast themselves. Now, for a few days following childbirth the breasts will produce a fluid known as cholesterol. Now, cholesterol is also known as first milk and cholesterol is a yellowish substance that is rich in protein and lactose but has a relatively low concentration of fat and this is usually produced before childbirth and following childbirth. For several days also following childbirth, what happens is the interior pituitary gland will release a hormone known as prolactin and what prolactin does is it stimulates the memory gland, it stimulates the gland cells in the memory gland to basically produce milk that is different than cholesterol. Now, the major difference between milk and the first milk is that milk actually contains a high concentration of carbohydrates as well as fat. And what the milk does is it once again provides immunity to the child by giving the child special types of antibodies.