| MEDICAL ANIMATION TRANSCRIPT: One of the endocrine functions of the pancreas is to secrete a hormone called insulin into the blood. Microscopic regions of beta cells in the pancreas are located on the islets of Langerhans. These beta cells release insulin. After consumption of a meal, increasing amounts of glucose in the blood trigger beta cells in the islets to secrete the appropriate amount of insulin hormone, which travels through the bloodstream to target cells, where it promotes the transport of glucose into the cells. Glucose must get inside cells to participate in cellular respiration, which creates the energy needed for cellular processes. Certain tissues, such as skeletal muscle and adipose tissue, require insulin to unlock their cells before glucose can enter. Insulin attaches to specific receptors on the cell's surface, causing glucose transporter proteins in the cell membrane to open, allowing glucose to pass into the cell. As cells take up glucose, the blood glucose level falls. Type 1 Diabetes is a disease in which the pancreas loses its ability to produce insulin, resulting in high blood glucose levels and other metabolic complications. In this disease, antibodies secreted by lymphocytes, attack and destroy the beta cells, so the pancreas produces little or no insulin. Lack of sufficient insulin prevents glucose from entering cells, resulting in a high blood glucose concentration, a condition called hyperglycemia. Unable to pass into cells, glucose builds up in the blood. The kidneys filter out the excess glucose, which is lost in urine, resulting in glycosuria, or large quantities of glucose in the urine. Common symptoms of hyperglycemia in type 1 diabetes include polyphagia, or excessive eating, polydipsia, or excessive thirst, polyuria, or increased urine volume, and unexplained weight loss. As the insulin deficiency continues, cells are unable to use sugar for energy, so the body breaks down fats and proteins to use them as an alternative source of energy. As fat break down continues, acidic byproducts, known as ketone bodies accumulate in the blood, resulting in a condition called ketosis. If allowed to build up to dangerously high levels, a life threatening condition called diabetic ketoacidosis results. Type 1 diabetes can cause degenerative tissue damage, resulting in long term complications such as atherosclerosis, blindness, neuropathy, and renal dysfunction. Licensed health professionals prescribe insulin replacement therapy to treat type 1 diabetes. If a diabetic person uses a syringe to deliver doses of insulin, he or she must rotate between injection sites to prevent localized tissue damage and absorption problems. Once delivered via syringe or insulin pump, the insulin rapidly reduces hyperglycemia, facilitating transport of glucose into cells. Insulin also suppresses ketosis, restoring metabolic balance. In addition to insulin therapy, patients must manage their glucose levels closely with frequent glucose checks, which should fall between 70 and 120 milligrams per deciliter. Patients should also monitor their blood glucose level with periodic hemoglobin A1C tests, which measure the amount of glycated hemoglobin in the blood over a two to three month period. Glycated hemoglobin is created when glucose attaches to hemoglobin within red blood cells. Glycated hemoglobin forms at a rate that increases with plasma glucose levels. The desired hemoglobin A1C level for people with diabetes is less than 7%. The higher the hemoglobin A1C level, the higher the risk of developing complications from diabetes. Other actions patients can take to monitor their glucose levels more closely are diet control and consistent exercise. By treating and controlling blood glucose levels, patients may prevent the occurrence of the complications of diabetes. [music] |
