Basal metabolic rate is under control of

Options

A. Glucagon
B. Insulin
C. Thyroxine
D. Both (1) and (2)

Answer

**Step-by-Step Solution:**

1. **Understanding Basal Metabolic Rate (BMR):**
- BMR is defined as the amount of energy expended while at rest in a neutrally temperate environment, in the post-absorptive state (meaning that the digestive system is inactive, which requires about 12 hours of fasting in humans).
- It is crucial for maintaining essential physiological functions such as breathing, circulation, and cellular production.

2. **Identifying Hormones Related to BMR:**
- The question provides four options: glucagon, insulin, thyroxine, and both insulin and glucagon.
- We need to analyze the role of each hormone in relation to BMR.

3. **Role of Glucagon:**
- Glucagon is secreted by the alpha cells of the pancreas.
- Its primary function is to increase blood sugar levels by promoting gluconeogenesis and glycogenolysis in the liver.
- Glucagon does not have a direct role in regulating BMR.

4. **Role of Insulin:**
- Insulin is secreted by the beta cells of the pancreas.
- It lowers blood sugar levels by facilitating the uptake of glucose into tissues and promoting its storage as glycogen.
- Like glucagon, insulin does not directly control BMR.

5. **Role of Thyroxine:**
- Thyroxine (T4) is a hormone produced by the thyroid gland.
- It plays a significant role in regulating metabolism, including BMR.
- Thyroxine increases the metabolic rate by stimulating the consumption of oxygen by metabolically active tissues, thereby influencing energy expenditure.

6. **Conclusion:**
- Among the hormones listed, thyroxine is the primary hormone that controls the basal metabolic rate.
- Therefore, the correct answer to the question is **thyroxine**.

**Final Answer: Thyroxine**

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