Islets of Langerhans are present in–

Correct option is D

Sol. The Islets of Langerhans are clusters of endocrine cells located in the pancreas. They play a key role in glucose metabolism by secreting hormones like insulin (β-cells), glucagon (α-cells), and somatostatin (δ-cells). Dysfunction in these cells is the underlying cause of diabetes mellitus, making them clinically very significant.
Explanation of each option:
· (a) Brain – Though the brain is affected by glucose levels, it does not produce insulin or glucagon. No islets of Langerhans are found here.
· (b) Stomach – Secretes digestive enzymes and gastric hormones like gastrin, but lacks endocrine cells responsible for glucose regulation.
· (c) Ovary – Involved in reproductive hormone production like estrogen and progesterone, not metabolic hormones like insulin.
· (d) Pancreas – Correct Answer. It contains both exocrine cells (digestive enzymes) and endocrine Islets of Langerhans, which are vital for blood glucose regulation.