The endocrine system is comprised of many organs located throughout the body that secrete hormones into the bloodstream to regulate cellular metabolic functions, such as the rates of chemical reaction for metabolism, growth, activity level, sexuality, etc.
The pituitary gland at the base of the brain is the "master gland" of the endocrine system. It sends out hormones as "messenger molecules" to regulate all the other hormone-producing organs of the body. The pituitary, in turn, is modulated by the limbic-hypothalamic system. This limbic-hypothalamic system is the major center for integrating this information with the processes of mind, and then transducing this newly integrated information to the pituitary, which in turn regulates all the other organs of the endocrine system.
Since many of the multiple functions of hormones are mediated either directly or indirectly by the limbic-hypothalamic-pituitary system, they are accessible to mind modulation and hypnotherapeutic intervention. That is, although hormones usually function autonomously, we now know that their activity is modulated by significant life experiences and encoded in the form of state-dependent memory, learning, and behavior.
The autonomic, endocrine, immune, and neuropeptide systems all operate by activating receptors on the surfaces of the individual cells of the tissues of the body. These receptors are like locks that must be opened to turn on the internal activities of the cells' cytoplasm (and even their genes).The neurotransmitters of the autonomic nervous system, the hormones of the endocrine system, and the immunotransmitters of the immune system, all function as "messenger molecules" or keys that open the receptor locks on the surface of the cells.
This messenger molecule and cell-receptor communication system is the psycho-biological basis of mind-body healing, therapeutic hypnosis, and holistic medicine in general. If each cell of the body is like a miniature factory, its receptors are locks on the doors. The autonomic, endocrine, immune and neuropeptide systems are communication channels whereby mind may activate genes and the internal cellular memory. The genes, of course, are the ultimate blueprints for building, organizing, and regulating how the cellular machinery works.
From the book "Psychobiology of Mind-Body Healing"
Psychobiology of Mind-Body Healing: New Concepts in Therapeutic Hypnosis
by Ernest Rossi
Rossi brings together extensive new evidence from psychoneuroimmunology, neuroendocrinology, molecular genetics, and neurobiology to show that there is no mysterious gap between mind and body. This book identifies what the medical profession calls "pathways", that is, the way attitudes or emotions are processed by the body in creating physiological or biochemical change. Rossi documents and illustrates how these pathways coordinate all the "messenger molecules" of mind-body communication via the autonomic, endocrine, immune, and neuropeptide systems.