Group 9

• Thermoregulation


  The control of body temperature in the body
• Endothermic animals


  • Maintain a constant body temperature in the face of different environmental temperatures
• Ectothermic animals


  • Have a body temperature that is the same as their environment and thus varies with the environment
• Blood glucose regulation


  Maintaining blood glucose levels at constant levels in the face of dynamic glucose intake and energy use by the body
• Glucose


  Key in the energy intake of humans
• Target range for blood glucose

  60-100 mg/dL for an adult
• Insulin


  Hormone released when there are high amounts of glucose in the bloodstream
• Glucagon


  Hormone released when there are low levels of glucose in the bloodstream
• Insulin


  Released from the beta cells in the islets of Langerhans found in the pancreas
• Insulin


  Released when there is a high concentration of glucose in the bloodstream
• Blood glucose regulation


  An excellent example of homeostatic control via negative feedback
• Negative feedback loop


  Any homeostatic process that changes in response to the detection of the stimulus, either increasing or decreasing the stimulus
• Maintaining normal blood glucose level


  1. Receptors sense change in blood sugar

  2. Control center (pancreas) secretes insulin

  3. Insulin lowers blood sugar levels

  4. Once homeostasis reached, pancreas stops releasing insulin
• Positive feedback loop


  Maintains the direction of the stimulus, possibly accelerating it
• Positive feedback loops in animal bodies


  • Cascade of chemical reactions that results in blood clotting or coagulation
• Osmosis


  Diffusion of water across a membrane in response to osmotic pressure caused by an imbalance of molecules on either side of the membrane
• Osmoregulation


  Process of maintenance of salt and water balance (osmotic balance) across membranes within the body fluids
• Body fluids


  Blood plasma, the cytosol within the cell, and interstitial fluid that exists in the spaces between cells and tissues of the body
• Electrolyte


  Solute that dissociates into ions during water dissolution
• Non-electrolyte


  Solute that does not dissociate into ions during water dissolution
• Both electrolytes and non-electrolytes contribute to the osmotic balance