+1 862 207 3288 It has been observed that among the higher animals various functions of the body are distributed in different organs and different systems of the body. This kind of arrangement is referred to as division of labor. While the stomach performs the digestion of food substances, concomitantly the kidneys remove the waste products of the body. In this way all the parts of the body keep on performing their respective functions simultaneously. When the legs are working, the heart does not stop beating. If the body did not function in this way animals would not survive. In spite of such a division of labor among living organisms, all these varied activities are regulated harmoniously. We know that the nervous and endocrine system is responsible for the regulation and control of these activities. The performance of the nervous system is dependent on nerve cell. Endocrines secrete special chemicals which are known as hormones. Hormones are carried by the blood to the distant parts of the body. Since the nerve impulse can be conducted at a speed of about 100 m /sec, which is much faster than the speed of hormone conduction, the nervous system is considered as important coordinators of body functions.
When we consider the fact that acetylcholine and adrenaline secretion regulate the motor nerves, muscles and glands, it becomes obvious that hormonal control is more important than the neural control. ‘Hormone’ is originally a Greek term which stands for the internal secretions. The term literally means ‘I stimulate’. Hormones activate various organs and systems. The secretion named adrenaline, synthesized and secreted by adrenal glands situated adjacent to the kidneys, forms bridges between the nerve terminals and muscles. If adrenaline were absent the passage of impulses through the nervous system would not initiate the contraction of muscles. Thus, the nervous and endocrine systems play similar roles in the regulation of different body functions. Both the systems release specific secretions. In the nervous system the neurosecretory cells act as the secretory elements whereas in the endocrine system hormones are secreted in to blood by the secretory cells. These hormones are carried by the blood to different parts of the body.
