In animals, chemical coordination is achieved through , the agency of hormones which function :as chemical messengers or informational molecules. Hormones are secreted in a very small amount by specialised tissues in the body called endocrine glands. 'these glands are ductless and pour their secretions directly into blood. Blood transports them to the target tissues organs. Hormones coordinate the activities of'living organisms and also their growth. For example, pancreas secretes two hormones-insulin and glucagon.
