Ch 18 Homeostasis Flashcards
Regulation of the blood glucose level
An increase in blood glucose level
- When chemoreceptors in the pancreas detect an increase in the blood glucose level, the pancreas produces more insulin and less glucagon. Insulin stimulates liver cells and muscle cells to convert more glucose into glycogen for storage. Insulin stimulates body cells to consume more glucose for respiration. As more glucose is taken up from the blood, the blood level decreases and returns to normal level.
A decrease in blood glucose level
- When chemoreceptors in the pancreas detect a decrease in the blood glucose level, the pancreas produces less insulin and more glucagon. Glucagon stimulates liver cells and muscle cells to convert stored glycogen into glucose. As more glucose is released into the blood, the blood glucose level increases and returns to normal.
Changes in blood glucose levels of a non-diabetic and a diabetic after drinking a glucose solution
- In the non-diabetic, glucose is absorbed from the small intestine into the blood and the blood level increases
- The high blood glucose level stimulates the pancreas to produce more insulin. Insulin stimulates liver cells and muscle cells to convert more glucose into glycogen, and stimulates body cells to consume more glucose. The blood glucose level decreases and is back to the normal range within 2 hours.
- In the diabetic, glucose uptake from the blood by liver cells and other body cells is inefficient. The blood glucose level rises more quickly and to a higher peak. The peak occurs later.
- Glucose is excreted in urine. The blood glucose level decreases slowly and is still higher than the initial level after 4 hours.
Glucose and insulin responses
Non-diabetics
- As the blood glucose level increases, the blood insulin level increases. A high blood glucose level stimulates the pancreas to produce more insulin.
- The blood glucose level then decreases. Insulin stimulates liver cells and muscle cells to convert more glucose into glycogen and stimulates body cells to consume more glucose.
- As the blood glucose level decreases, the blood insulin level decreases. A low blood glucose level stimulates the production of glucagon, which inhibits the production of insulin in pancreas.
Type 1 (insulin-dependent diabetics)
- The blood glucose level increase, but the blood insulin level is lower than that of the non-diabetic and shows little change. The pancreas produces too little or no insulin.
Type 2 (insulin-independent diabetics)
- The blood insulin level increases, but the glucose level remains higher than normal. The body cells are insensitive to the insulin produced
Controlling the severity of type 2 diabetes
- Eat smaller portions of food but more frequently
- Reduce the intake of food with high sugar content
- Take regular exercise
- Frequent monitoring of blood glucose levels
- Take appropriate medication