Homeostasis

• Homeostasis is the maintenance of a constant internal env
• The effect of insulin is to help move glucose from blood to cells.
• Insulin decreases blood glucose by:

  • increasing the rate of glucose uptake by cells
  • make cell membranes more permeable to glucose
  • stimulate liver+muscle cells convert excess glucose - glycogen
• Lack of insulin secretion result in:

  1. abnormally high blood glucose conc
  2. tissue cells cant store/utilise glucose
  3. weak body, glucose in urine
  4. diabetes mellitus
• Over secretion of insulin:

  • abnormally low blood glucose conc

  symptoms:

  • hunger
  • irritability
  • fast heartbeat
• Effects of glucagon:

  • Islets of langerhans increase secretion when blood glucose conc decreases
• glucagon increases B.G.C by:

  • converts glycogen to glucose
  • too much glucagon - over activity
  • too little - weak

  glucagon’s main target : liver (place where glucagon goes for action)

  • fats and amino acids
  • glycogen
  • lactic acid

  all converted to glucose
• what is diabetes mellitus ?

  condition where blood conc cannot be regulated within normal limits
• What happens during diabetes mellitus?

  There’s insufficient insulin secretion

  b.g levels reach high and kidneys unable to completely reabsorb all glucose

  >glucose in urine
• What is type 1 diabetes?

  • Insulin dependant
  • early onset
  • insufficient/no insulin secretion
  • treatment - injection, exercise
• What is type 2 diabetes?

  • insulin independant
  • late onset, overweight people prone
  • insulin produced, but muscles dont respond well
  • inuslin produced in small amounts,defective
  • treatment - control diet, exercise
• negative feedback is a change in level triggers an automatic response that leads to restoration of original level
• diabetis mellitus is the condition where there is persistent increase than normal blood glucose level concentration.

  Due to body’s resistance to insulin or insufficient production if insulin
• Principles of homeostasis:

  1. its a negative feedback process where a stimulus which brings about a change in the internal environment, 2. will trigger corrective mechanism which lead to restore system back to its original state.