Endocrine system work on regulation and control of the body.. Send chemical messages that are hormones through blood to tissues or organs in the body such as muscles

Endocrine system work on regulation and control of the body:
This device sends chemical messages, which are hormones through the blood to tissues or organs in the body called: target.
Such as: the muscles respond to these messages and change of activity, such as feeling hungry feeling thirsty.
* Note: In this case the body's response to these hormones is slow.