Question

Parathormone causes

• A. Increased level of serum calcium
• B. Increased level of blood sugar
• C. Decreased level of serum calcium
• D. Decreased level of blood sugar

Answer 1

Answer: (A)

Increased level of serum calcium

The parathyroid glands secrete a peptide hormone called parathyroid hormone or parathormone (PTH). The release of parathormone is regulated by the circulating levels of calcium ($C{a}^{2+}$) ions in the blood. PTH plays an important role in calcium balance of the body. It maintains the calcium balance between the blood and other tissues. When the calcium level in the blood decreases, parathyroid hormone is released in order to increase the calcium level in the blood. PTH acts on bones and other skeletal structure and mobilizes the calcium ($C{a}^{2+}$) from the bones into the blood. This is called bone resorption/dissolution/demineralization. The parathormone also increases the reabsorption of calcium by the renal tubules and absorption of calcium from the digested food. Hence, parathormone causes increased level of serum calcium.