What is the primary function of parathyroid hormone regarding bone?

What is the primary function of parathyroid hormone regarding bone?

• A. It stimulates growth of bone
• B. It regulates calcium levels in the blood
• C. It inhibits osteoblast activity
• D. It affects cartilage cell growth

Answer: (B)

The primary function of parathyroid hormone (PTH) is to regulate calcium levels in the blood, making this choice the most accurate. PTH is secreted by the parathyroid glands and plays a critical role in maintaining calcium homeostasis. When blood calcium levels drop, PTH increases, which triggers a series of physiological responses aimed at raising those levels. PTH acts on various target organs. In the bones, it stimulates osteoclast activity, which leads to bone resorption and the release of calcium into the bloodstream. This process is essential for increasing the availability of calcium for vital bodily functions. Additionally, PTH enhances renal reabsorption of calcium and promotes the activation of vitamin D, which subsequently increases intestinal absorption of calcium. While growth of bone, osteoblast activity, and cartilage cell growth are important aspects of bone health and development, they are not the primary functions of PTH. Instead, PTH’s primary role is to ensure that calcium levels in the blood remain stable and within a healthy range.

The primary function of parathyroid hormone (PTH) is to regulate calcium levels in the blood, making this choice the most accurate. PTH is secreted by the parathyroid glands and plays a critical role in maintaining calcium homeostasis. When blood calcium levels drop, PTH increases, which triggers a series of physiological responses aimed at raising those levels.

PTH acts on various target organs. In the bones, it stimulates osteoclast activity, which leads to bone resorption and the release of calcium into the bloodstream. This process is essential for increasing the availability of calcium for vital bodily functions. Additionally, PTH enhances renal reabsorption of calcium and promotes the activation of vitamin D, which subsequently increases intestinal absorption of calcium.

While growth of bone, osteoblast activity, and cartilage cell growth are important aspects of bone health and development, they are not the primary functions of PTH. Instead, PTH’s primary role is to ensure that calcium levels in the blood remain stable and within a healthy range.