22. Regulation of the glucose metabolism – maintenance of the blood glucose concentration. Regulatory enzymes and hormones. Mechanisms. Hypoglycemia, hyperglycemia, glycosuria.

Glucose Homeostasis:

• The body tightly regulates blood glucose levels to ensure a constant supply of energy for cellular functions.
• Glucose homeostasis involves a balance between glucose uptake from the diet, glucose production via gluconeogenesis, and glucose utilization in tissues.

Role of Different Tissues and Organs:

Liver:

• The liver plays a central role in glucose homeostasis, acting as a glucose buffer.
• It stores excess glucose as glycogen during periods of high blood glucose (postprandial state) and releases glucose into the bloodstream when needed (fasting state).
• Additionally, the liver is involved in gluconeogenesis, the synthesis of glucose from non-carbohydrate precursors such as lactate, glycerol, and amino acids.

Muscle:

• Muscle tissue can store glucose in the form of glycogen for its own energy needs.
• During exercise or periods of high energy demand, muscle glycogen is broken down to provide glucose for glycolysis and ATP production.

Role of Different Tissues and Organs:

Adipose Tissue:

• Adipose tissue stores excess energy in the form of triglycerides.
• It can also release glycerol, a precursor for gluconeogenesis, and free fatty acids, which can be used as an alternative energy source during prolonged fasting.

Pancreas:

• The pancreas secretes insulin and glucagon, two hormones that regulate blood glucose levels.
• Insulin promotes glucose uptake by cells, glycogen synthesis, and lipogenesis, leading to a decrease in blood glucose levels.
• Glucagon stimulates glycogenolysis and gluconeogenesis in the liver, increasing blood glucose levels.