Question

The malfunctioning of which endocrine gland causes diabetes?
A) Thyroid gland
B) Pancreas
C) Pituitary gland
D) hypothalamus

Answer 1

A gland situated behind and below the stomach, elongated and somewhat flattened organ having both exocrine and endocrine functions.

Complete answer:
Pancreas is both an exocrine and an endocrine gland. As an endocrine gland (produce and release hormones directly into the bloodstream) it regulates blood sugar level (glucose) by secreting two hormones Insulin and glucagon by Islets of Langerhans both have antagonist function. Insulin (secreted by beta cells of Islets of Langerhans) reduces the blood glucose level whereas glucagon (α - cells) increases. Insulin helps the cells (especially of liver and muscle) to take glucose from the bloodstream and store it. In normal healthy people both the hormones work together to regulate the blood glucose level. Diabetes is of two types: type 1 diabetes previously called insulin-dependent diabetes mellitus (IDDM) and type 2 diabetes previously called non-insulin-dependent diabetes mellitus (NIDDM), more common and accounts for 90% of all diabetes. In diabetes mellitus, pancreas does not produce enough insulin results in an increase in blood sugar level. In type 1 diabetes insulin is not produced due to destruction of beta cells due to which cells are unable to take up the glucose results an increase in sugar level. Type 2 diabetes occurs when the body does not produce enough insulin or cells are resistant to insulin, thus sugar is unable to move inside the cells, resulting in accumulation in the bloodstream. Increase in blood sugar level stimulates the beta cells of pancreas to secrete more insulin which eventually impaired the cells making them unable to produce enough insulin. Diabetes insipidus should not be confused with diabetes mellitus. Diabetes insipidus is not due to pancreatic hormones but due to Anti-diuretic hormone (ADH) a hormone produced by the hypothalamus and secreted by the pituitary gland. Diabetes insipidus patients have normal blood sugar level. Antidiuretic hormone (ADH) also called vasopressin regulates the fluid balance in the body.

Thus, the correct answer is option B. i.e., pancreas.

Note: To maintain the normal blood sugar level, balance between insulin and glucagon is very important. In diabetes insulin secretion and the response of the target cell is also crucial.