The hormones of the anterior pituitary gland are under the control of releasing hormones from the hypothalamus. The two reproductive hormones of the anterior pituitary gland, FSH and LH, are under the control of gonadotropin releasing hormone (GnRH). GnRH is secreted by neuroendocrine secretary cells of the hypothalamus and transported to the anterior pituitary gland by hypothalamo-pituitary portal vessels. Increasing levels of FSH and LH begin the menstrual cycle.