ABSTRACT
This chapter examines body systems that permit our mind and emotions to interact or communicate with the environment and, thus, to induce positive or detrimental physiological changes. The nervous system is lightning fast, but it has a very poor memory. The heart also is currently being studied as another nervous system. It is known that upper chambers of the heart, called the atria, secrete a hormone called atrial natriuretic hormone, which decreases blood pressure and volume. The Autonomic Nervous System (ANS) connects the central nervous system (CNS) with numerous motor organs: the smooth muscles of the heart, gastrointestinal system, and the blood vessels as well as the adrenal, pancreas, and salivary glands. A signal coming from the CNS to any skeletal muscle takes a nonstop route. A signal coming from the CNS to an ANS organ passes the message along via nerve cell bodies called ganglions.
