• They are organic chemical substance(usually proteins or steroids).hormones are secreted by ductless and endocrine glands directly into the blood stream
  • Hormones performs several biological functions such as;
  • Insulin for lowering blood glucose concentration
  • Anti-diuretics hormone, ADH for promoting reabsorption of water in the kidney
  • Gastric stimulate the secretion of gastric juice etc. The name is derive from a Greek word meaning it arouses to activity
  • Each hormones has its own target cell on which it acts; therefore each has its own specific effect on the body
  • Hormones are often effective in very small concentrations
  • Most hormones are either excreted in the urine or broken down by enzymes quite quickly.