Now in fact, the hypothalamus plays such an important role in the endocrine system we call the hypothalamus the master gland of the endocrine system of the human body. So let's take a look at the following diagram. So we have the hypothalamus of the forebrain. We have the medium eminence which is the bottom portion of the hypothalamus and this is our pituitary gland also known as the hypothesis. This is the front portion, the interior pituitary gland and the back portion, the posterior pituitary gland. Now, what exactly connects, what links the hypothalamus to the interior pituitary gland?