8 - The endocrine system

• Gland


  an organ that synthesizes substances e.g hormones, to the secreted somewhere else in the body
• Hormone


  a chemical substance produced in the body that regulates and controls a range of bodily functions
• Homeostasis


  the tendency of the body to regulate its internal conditions, usually by a system of the feedback controls
• Target Cell


  a unique cell which does a specific job when a specific hormone attaches to it
• Receptor


  a specific site on a cell designed to recognise and accept the specific hormone
• Circulating hormones


  travel around in the bloodstream delivering messages to cells to perform a function which will help the body return to homeostasis

  E.G ADRENALINE & TESTOSTERONE
• Local Hormones


  act on neighbouring cells without entering the bloodstream and are usually inactivated (turn off) quickly

  E.G GLUCAGON & SEROTONIN