HORMONES: REGULATION AND ACTION
This section presents the major endocrine glands, their hormones and how they are regulated, the effects the hormones have on tissues, and how some of the hormones respond to exercise. This information is essential to discuss the role of the neuroendocrine system in the mobilization of fuel for exercise.
Hypothalamus and the Pituitary Gland
The pituitary gland is located at the base of the brain, attached to the hypothalamus. The gland has
two lobes-the anterior lobe (adenohypophysis), which is a true endocrine gland, and the posterior lobe (neurohypophysis), which is neural tissue extending from the hypothalamus. Both lobes are under the di-rect control of the hypothalamus. In the case of the anterior pituitary, hormone release is controlled principally by chemicals (releasing hormones or factors) that originate in neurons located in the hypothalamus. These releasing hormones stimulate or inhibit the release of specific hormones from the anterior pituitary. The posterior pituitary gland re- ceives its hormones from special neurons originating in the hypothalamus. The hormones move down the axon to blood vessels in the posterior hypothalamus where they are discharged into the general circulation (37, 75)