Question

Structure A secretes a hormone, identify the correct combination of the hormone and function secreted by it ?

• A. Thyroxine - increased calcium levels in blood
• B. Thymosin - increased blood sugar level
• C. Parathyroid hormone - decrease in blood calcium level
• D. Growth hormone - metabolism of carbohydrate ,fats and proteins

Answer 1

The correct option is C Parathyroid hormone - decrease in blood calcium level

The structure marked A is parathyroid gland and secretes parathyroid hormone also called parathormone. Parathyroid hormone (PTH) increases the Ca2+ levels in the blood. PTH acts on bones and stimulates the process of bone resorption (dissolution/ demineralisation).When the calcium in our blood falls below normal, the parathyroid glands make more PTH. Increased PTH causes more absorption of calcium from bone and releases it into the blood.
Thyroxine has no role in regulating calcium levels in blood. Thyroid gland also secretes a protein hormone called thyrocalcitonin (TCT) which regulates the blood calcium levels. It lowers the blood calcium levels when blood calcium levels increase more than normal.
Growth hormone is responsible for growth of the body. Thyroid hormones regulate the metabolism of carbohydrates, proteins and fats.