ABSTRACT
Acting through the anterior lobe of the pituitary gland the hypothalamus controls five endocrine axes. Between them these neuroendocrine axes regulate key aspects of metabolism, reproduction, development and growth. The five axes share many common features. Neurons, located in several hypothalamic nuclei, send their axons to the external zone of the median eminence and the tuberoinfundibular tract. The Hypothalamic–pituitary–adrenal axis regulates the synthesis and secretion of glucocorticoids, a group of steroid hormones which help to control the metabolism of energy substrates. Secretion from the neuroendocrine axes is modulated by feedback acting at several levels which tends to defend a set point in the concentration of the end product. The increased secretion of glucocorticoids is useful in stress. Glucocorticoids mobilize fats and amino acids from fat and muscle cells respectively. These are used as substrates for gluconeogenesis in the liver.
