Homeostasis & control of blood glucose

  • discuss the importance of homeostasis in mammals and explain the principles of homeostasis in terms of internal and external stimuli, receptors, central control, co-ordination systems, effectors (muscles and glands)
  • define the term negative feedback and explain how it is involved in homeostatic mechanisms
  • outline the roles of the nervous system and endocrine system in coordinating homeostatic mechanisms, including thermoregulation, osmoregulation and the control of blood glucose concentration
  • explain how the blood glucose concentration is regulated by negative feedback control mechanisms, with reference to insulin and glucagon
  • outline the role of cyclic AMP as a second messenger with reference to the stimulation of liver cells by adrenaline and glucagon
  • describe the three main stages of cell signalling in the control of blood glucose by adrenaline as follows:
    • hormone-receptor interaction at the cell surface
    • formation of cyclic AMP which binds to kinase proteins
    • an enzyme cascade involving activation of enzymes by phosphorylation to amplify the signal
  • explain the principles of operation of dip sticks containing glucose oxidase and peroxidase enzymes, and biosensors that can be used for quantitative measurements of glucose in blood and urine
  • explain how urine analysis is used in diagnosis with reference to glucose, protein and ketones