(16) Hormonal Regulation of Blood Glucose Level | Role of Insulin, Glucagon, & Other Hormones

Summary

This video explains the hormonal regulation of blood glucose levels, focusing on how the body maintains glucose balance through hormones like insulin and glucagon. Insulin lowers blood glucose by promoting glycogen formation in the liver and enhancing glucose uptake by cells. In contrast, glucagon increases glucose levels by stimulating glycogen breakdown and gluconeogenesis. The video also discusses other hormones such as epinephrine, cortisol, growth hormone, and thyroxine, which affect glucose regulation through various mechanisms, ultimately ensuring the body's energy needs are met and blood glucose remains stable.

Takeaways

• 😀 Insulin helps regulate blood glucose by promoting glucose uptake in cells and converting excess glucose into glycogen (glycogenesis) in the liver.
• 😀 Glucagon raises blood glucose levels by stimulating the breakdown of glycogen (glycogenolysis) and promoting glucose production (gluconeogenesis) when blood glucose is low.
• 😀 Insulin is a hypoglycemic hormone that lowers blood glucose levels by encouraging glucose absorption and utilization.
• 😀 Glucagon is a hyperglycemic hormone that increases blood glucose levels when they fall below normal, typically during fasting or between meals.
• 😀 Epinephrine (adrenaline) also raises blood glucose by stimulating glycogenolysis and reducing insulin release during stress or physical exertion.
• 😀 Glucocorticoids (e.g., cortisol) increase blood glucose levels by promoting gluconeogenesis and inhibiting insulin's glucose utilization effects.
• 😀 Growth hormone raises blood glucose by reducing glucose uptake in cells and counteracting insulin’s effects.
• 😀 Thyroxine increases blood glucose levels by stimulating glycogenolysis and gluconeogenesis in the liver.
• 😀 The pancreas plays a crucial role in regulating blood glucose, releasing insulin (from beta cells) when glucose is high and glucagon (from alpha cells) when glucose is low.
• 😀 Insulin and glucagon are the main hormones responsible for maintaining normal blood glucose levels, while other hormones like epinephrine, glucocorticoids, and growth hormone also influence glucose regulation.

Q & A

What is the primary role of hormones in blood glucose regulation?

Hormones regulate blood glucose levels by either increasing or decreasing glucose in the blood, ensuring it stays within a normal range. Insulin lowers blood glucose when it's too high, while glucagon raises it when it drops too low.

How does insulin lower blood glucose levels?

Insulin promotes the uptake of glucose by cells and stimulates the conversion of excess glucose into glycogen in the liver. It also encourages glycolysis, where glucose is used for energy, thereby reducing the blood glucose level.

What happens when blood glucose levels rise after eating carbohydrates?

When blood glucose levels rise, the pancreas releases insulin. Insulin helps store excess glucose as glycogen in the liver and promotes glucose uptake by various cells, lowering the glucose level back to normal.

What is glycogenesis, and how does it relate to insulin?

Glycogenesis is the process where glucose is converted into glycogen for storage, mainly in the liver. Insulin promotes this process, helping to reduce excess blood glucose levels by storing it as glycogen.

What is the role of glucagon when blood glucose levels fall?

When blood glucose levels decrease, glucagon is released by the pancreas. It stimulates glycogenolysis in the liver, where glycogen is broken down into glucose and released into the blood to increase blood glucose levels.

How does glucagon contribute to glucose production besides glycogenolysis?

In addition to glycogenolysis, glucagon also promotes gluconeogenesis, the synthesis of glucose from non-carbohydrate sources like lactate and amino acids, to help raise blood glucose levels during fasting or between meals.

What are hypoglycemic and hyperglycemic hormones?

Hypoglycemic hormones, like insulin, lower blood glucose levels, while hyperglycemic hormones, like glucagon and epinephrine, increase blood glucose levels.

How does epinephrine affect glucose metabolism?

Epinephrine, released from the adrenal medulla, increases glycogenolysis in the liver and muscles, promoting the breakdown of glycogen into glucose. It also inhibits insulin release and reduces glucose uptake by cells, increasing blood glucose levels.

What impact does cortisol have on blood glucose levels?

Cortisol, a glucocorticoid hormone released from the adrenal cortex, increases gluconeogenesis, the synthesis of glucose, and antagonizes the action of insulin, which raises blood glucose levels by reducing glucose uptake and utilization in cells.

How does thyroxine influence blood glucose regulation?

Thyroxine, released from the thyroid gland, increases blood glucose levels by stimulating glycogenolysis and gluconeogenesis in the liver, promoting the breakdown of glycogen and the production of glucose.