Insulin keeps glucose level within the narrow limit. It is released in response to the rapid rise in blood glucose level. The hormone that tends to increase glucose level in the blood is:

Glucagon

The correct answer is option 1. Glucagon.

Let us dive into the roles of the hormones mentioned and how they relate to blood glucose regulation.

Glucose Regulation in the Body

The body maintains blood glucose levels within a narrow range through the actions of various hormones. This regulation is crucial for providing energy to cells while avoiding the harmful effects of too high or too low glucose levels.

Key Hormones Involved in Glucose Regulation

Insulin

Produced by: Beta cells of the pancreas.

Function: Lowers blood glucose levels.

Mechanism:

After eating, blood glucose levels rise. In response, insulin is released into the bloodstream. Insulin facilitates the uptake of glucose into cells, especially muscle and fat cells, where it is used for energy. Insulin also promotes the conversion of glucose to glycogen in the liver (glycogenesis) for storage.

Outcome: Blood glucose levels decrease as glucose is taken up by cells and stored.

Glucagon

Produced by: Alpha cells of the pancreas.

Function: Increases blood glucose levels.

Mechanism:

When blood glucose levels are low, such as between meals or during fasting, glucagon is released. Glucagon signals the liver to break down glycogen into glucose (glycogenolysis). It also promotes the production of glucose from non-carbohydrate sources like amino acids and fats (gluconeogenesis).

Outcome: Blood glucose levels increase as glucose is released into the bloodstream from the liver.

Other Hormones that Influence Blood Glucose Levels

Epinephrine (Adrenaline)

Produced by: Adrenal medulla (inner part of the adrenal glands).

Function: Increases blood glucose levels, especially during stress or "fight-or-flight" situations.

Mechanism:

Epinephrine stimulates glycogenolysis in the liver and muscles, releasing glucose into the blood. It also inhibits insulin secretion, ensuring that glucose remains available in the bloodstream.

Outcome: Provides a quick surge of glucose for energy in response to stress.

4. Cortisol (Produced by the Adrenal Cortex)

Produced by: Adrenal cortex (outer layer of the adrenal glands).

Function: Increases blood glucose levels, primarily in response to long-term stress.

Mechanism:

Cortisol promotes gluconeogenesis, which is the production of glucose from non-carbohydrate sources like proteins and fats. It also reduces the uptake of glucose by certain tissues, ensuring that more glucose remains in the blood.

Outcome: Sustains blood glucose levels during prolonged stress.

Irrelevant Hormone for Glucose Regulation

Estradiol

Produced by: Ovaries (in females) and adrenal glands.

Function: Estradiol is a type of estrogen, a sex hormone involved in reproductive and sexual development.

Relevance: Estradiol is not directly involved in glucose regulation and does not have a significant impact on blood glucose levels.

Conclusion

Glucagon (Option 1) is the primary hormone that increases blood glucose levels by promoting the breakdown of glycogen and stimulating gluconeogenesis in the liver.  While epinephrine (adrenaline) and cortisol also increase blood glucose levels, glucagon is the key hormone directly responsible for responding to low blood glucose levels.

Thus, the correct answer to the question about which hormone tends to increase blood glucose levels is Option 1: Glucagon.