Continuous with the hypothalamus inferiorly is the pituitary gland. These two structures are connected by the infundibulum and hypophysial stalk just caudal to the optic chiasm (eFig. 9.87). The intimate relationship of the hypothalamus to the portal circulation of the pituitary gland allows the hypothalamus to be an efficient regulator of hormone synthesis and release. Releasing and inhibiting factors synthesized by the hypothalamus pass through these portal vessels via the tuberoinfundibular tract (eFig. 9.89) to reach the anterior pituitary (adenohypophysis) and control release of hormones produced by the anterior pituitary such as adrenocorticotropic hormone, luteinizing hormone, follicle-stimulating hormone, thyroid-stimulating hormone, growth hormone, and prolactin (eFig. 9.90).