Question
Where is insulin secreted, and what is its effect on blood glucose concentration?
▶️ Answer/Explanation
Solution
Ans: D
Insulin is secreted by the pancreas (specifically the β-cells in the islets of Langerhans) and functions to decrease blood glucose concentration. It promotes glucose uptake by cells and storage as glycogen in the liver and muscles.
The liver (A, C) secretes glucagon, not insulin, while the pancreas’s role in lowering blood glucose (D) is correct. Thus, the answer is D (Pancreas; decreases blood glucose).
Question
What is the role of insulin?
▶️ Answer/Explanation
Solution
Ans: A
Insulin is a hormone secreted by the pancreas in response to high blood glucose levels. Its primary functions are:
- Promoting glucose uptake by cells (especially liver, muscle, and fat cells).
- Stimulating the conversion of glucose into glycogen (glycogenesis) in the liver and muscles.
- Inhibiting gluconeogenesis (glucose production) in the liver.
These actions collectively lower blood glucose concentration, making option A correct.