Sutures and Wound Repair/ General Surgery (ABSA) Practice Test

Which hormones play a crucial role in regulating calcium and phosphate metabolism?

1. Thyroid hormones

2. Insulin

3. Parathyroid hormones

4. Adrenaline

The correct answer is: Parathyroid hormones

Parathyroid hormones are essential for regulating calcium and phosphate metabolism in the body. They are secreted by the parathyroid glands and play a critical role in maintaining appropriate levels of calcium in the bloodstream. When calcium levels drop, parathyroid hormone is released to stimulate several processes: it promotes the conversion of vitamin D into its active form, which enhances intestinal absorption of calcium; it encourages the release of calcium from bones into the bloodstream; and it reduces the loss of calcium in urine by increasing renal tubular reabsorption. In terms of phosphate metabolism, parathyroid hormones work to decrease phosphate reabsorption in the kidneys, leading to increased phosphate excretion. This intricate balance is vital, as calcium and phosphate work together in numerous biological processes, including bone health. Thyroid hormones, insulin, and adrenaline do not directly regulate calcium and phosphate metabolism. Thyroid hormones primarily regulate metabolism and energy use, insulin is critical for glucose metabolism, and adrenaline is primarily involved in the body's fight-or-flight response. Therefore, parathyroid hormones are uniquely positioned to manage the delicate equilibrium of calcium and phosphate in the body.