Control of blood glucose levels

Regulation of Blood Glucose Levels

The body maintains a constant level of glucose in the blood to ensure it can provide energy to cells. This process is known as glucose homeostasis.
The hormones insulin and glucagon play crucial roles in regulating blood glucose levels.
The pancreas is responsible for producing and releasing these hormones in response to high or low blood glucose levels.
Both of these hormones function to keep blood glucose levels from getting too high or too low, thereby maintaining a state of equilibrium in the body.

Role of Insulin

Insulin is produced and secreted by beta cells in the pancreas when blood glucose levels are high, such as after eating a meal.
It promotes the uptake of glucose by most body cells, including skeletal muscle and fat cells.
Insulin also promotes the synthesis of glycogen in the liver, converting excess glucose into a storage form for later use.
The effect of insulin is to lower the concentration of glucose in the blood.

Role of Glucagon

Glucagon is produced and secreted by alpha cells in the pancreas when blood glucose levels are low, such as during fasting or between meals.
It promotes the breakdown of glycogen into glucose in the liver, increasing the concentration of glucose in the blood.
Glucagon also stimulates the process of gluconeogenesis, which is the creation of glucose from non-sugar sources in the liver.
The effect of glucagon is to raise the concentration of glucose in the blood.

Interplay between Insulin and Glucagon

The interplay between insulin and glucagon ensures that the concentration of glucose in the blood stays within a narrow range.
When blood glucose levels rise, the pancreas secretes insulin which helps to lower glucose levels.
When blood glucose levels drop, the pancreas secretes glucagon to increase glucose levels.
This complementary action of insulin and glucagon ensures that cells receive a constant and steady supply of glucose for energy production.

Disorders Related to Blood Glucose Control

Diabetes mellitus is a condition in which the body cannot properly control blood glucose levels, often due to insufficient insulin production (Type 1) or resistance to the effects of insulin (Type 2).
Both types of diabetes result in high blood glucose levels (hyperglycaemia), which can damage blood vessels and various organs in the long term.
Hypoglycaemia, or low blood glucose, can occur if too much insulin is present in the blood. If not treated promptly, hypoglycaemia can lead to symptoms including fatigue, faintness, and even loss of consciousness.
Regularly monitoring blood glucose levels and adopting appropriate dietary and medical strategies can help manage these conditions.