Control of blood glucose concentration 5.3.2

• it is important to control blood glucose levels because if the sugar level is too high, water moves from high water potential (cells) to low water potential (blood) to dilute the sugar - dehydrating and damaging cells
• having a recent meal and hormonal imbalances cause blood glucose levels to go up
• not having a meal and hormonal responses in the body cause the blood glucose levels to go down
• your pancreas monitors blood glucose levels
• when the levels are too high, it releases a hormone called insulin, insulin causes two things to happen:

  1. excess glucose is converted and stored as insoluble glycogen in the liver and in muscles
  2. cells take up glucose and use it for respiration

  therefore, blood glucose levels fall
• when blood glucose levels are too low, the pancreas releases another hormone called glucagon

  glucagon causes the liver to break down stored glycogen into soluble glucose, which is released back into the bloodstream for cells to use in respiration

  glucose levels then rise again
• negative feedback is when the response causes the opposite of the change to make it the original level, to ensure the middle ground is maintained
• insulin is a hormone that decreases blood sugar by converting glucose to glycogen
• glucagon is a hormone that increases blood sugar by converting glycogen to glucose
• glycogen is a storage molecule found in mammals
• diabetes mellitus is a disease where a person is unable to properly control their blood glucose level
• the cause of type 1 diabetes is that the body doesnt make enough or makes no insulin, type 1 diabetes has a stronger genetic influence
• the cause of type 2 diabetes is that the body makes insulin but doesnt make enough and the cells stop responding to it
• the short term symptoms of type 1 and 2 diabetes are

  • general tiredness (not much energy from food)
  • weight loss
  • frequent urination
  • thirst
• the long term symptoms of type 1 diabetes are:

  • loss of eyesight
  • kidney function and circulatory system issues
  • nerve damage
• there are less long term type 2 diabetes due to a combination of age, obesity and lack of exercise
• treatments of type 1 diabetes include:

  • insulin injections before and after meals as needed (the levels are monitored and the dose is adjusted as needed)
  • pancreas transplant
  • gene therapy/ adult stem cell engineering
• treatments of type 2 diabetes include:

  • controlling diet
  • exercising more frequently
  • losing weight
  • drugs to help insulin be more effective
  • drugs to help pancreas make more insulin
  • reduce the amount of glucose being absorbed
  • insulin injections only if other measures are not adhered to or effective
• its good to have a high carbohydrate and low sugar diet if you are diabetic because the glucose is absorbed slowly, so the net effect stays lower
• diabetics often feel tired because their blood glucose levels are too low
• diabetics have trembling hands because the high blood glucose causes nerve damage
• diabetics feel tired because the high blood glucose reduces water concentration of the blood\
• diabetics feel thirsty because the high blood glucose reduces the water concentration of their blood
• each type 1 diabetes patient needs their own individual insulin dose because some people may be able to make some insulin on their own whereas some people may not be able to make any
• diabetic patients have sugar in their urine because it cannot be converted and stored so the excess glucose gets flushed away with the urine
• insulin is usually injected because it is a protein and would therefore be broken down in digestion if taken by mouth