Acharya Mahaprajna
The nervous system and the endocrine system are the two major controlling and coordinating systems of our body. They coordinate the work of other systems and through them controls the functions of the body as a whole. Both are intimately associated with each other and, together, integrate the organism. The functional interlocking between both qualifies them to be regarded as constituting a single integrated system called "neuro-endocrine system".
The endocrine glands communicate their orders through chemical regulators called hormones. They participate in all bodily functions. These chemical messengers exert profound influence on the mental states, emotions and behavioural patterns of an individual They are the prime movers which generate the powerful forces of all the instincts and urges, passions and emotions in man. These, in turn, generate feelings and demand appropriate action that satisfied the need. Love, hate, fear etc. are endocrine expressions.
For a long time it was believed that the brain was the source of energy and the seat of impulses of man. Significant progress in endocrinology (branch of science dealing with endocrine system) in the recent years has established that the passions and emotions are expressions of the endocrine system.
Endocrine system is the seat of habit formation in a person. They manifest themselves in the nervous system and become behavioural pattern. Thus manifestation and behaviour are the functions of the nervous system, but the birthplace - the production centre of the habits - is the endocrine system. The same habits are then stored in the brain as memories (i.e. the brain is only the repository of memories), and ultimately become patterns of behaviour. The word neuro-endocrine system is very apt to describe the integration of both systems.
The endocrine glands are comparatively small ductless and have access to very rich vascular supply. Hormones reach their targets through blood stream. They are effective in very small quantities. They regulate such important body-processes as growth and development, sexual activity, pregnancy and birth, and metabolism.
For the most part, hormone-secretion of the endocrine system is under the control of the pituitary. A variety of hormones secreted by the pituitary reach other glands via the blood- streams and stimulate each to secrete specific hormones in definite quantities. Through a feedback system of chemical inter-communication, pituitary regulates the hormone production of the glands, (see fig. I).
