Homeostasis

• Homeostasis is the regulation of internal condition of a cell or organism to maintain optimum conditions for function, in response to internal and external changes (your body's way of keeping things the same despite changes inside or outside your body.)
• The conditions that need to be kept constant include water content, temperature, and blood glucose levels
• Water content: too high or too low can cause the cells to swell or shrink as water moves in or out by osmosis
• Temperature: must be high enough for kinetic energy for chemical reactions to take place, but too high could denature enzymes
• Blood glucose levels: glucose needed to release energy from respiration, cells need it for active transport or protein synthesis, they would die without enough glucose
• homeostasis is important for maintaining optimal conditions for enzyme action and all cell functions
• any control system in the body require three components:

  • receptors
  • coordination centres
  • effectors
• Receptors are cells which detect stimuli (changes in the internal or external environment). For

  example, receptors in your ear detect sound, eye receptors detect light and skin receptors detect

  pain, temperature and touch.
• Coordination centres receive and process information from receptors. EIt includes the brain and

  spinal cord.
• Effectors are muscles or glands which bring about responses which restore optimum levels.

  Muscles contract to move body parts and glands release hormones.
• The automatic control systems may involve nervous or chemical responses