GENERAL HISTOLOGY

Detailed explanation-1: -Parathyroid hormone (PTH) levels are mainly controlled by a feedback loop of calcium levels in your blood to your parathyroid glands. In other words, low calcium levels in your blood stimulate parathyroid hormone release, whereas high calcium levels in your blood prevent your glands from releasing parathyroid hormone.

Detailed explanation-2: -Parathyroid hormone is mainly controlled by the negative feedback of calcium levels in the blood to the parathyroid glands. Low calcium levels in the blood stimulate parathyroid hormone secretion, whereas high calcium levels in the blood prevent the release of parathyroid hormone.

Detailed explanation-3: -The parathyroid hormone (PTH), secreted by the parathyroid glands, is responsible for regulating blood calcium levels; it is released whenever blood calcium levels are low. PTH increases blood calcium levels by stimulating osteoclasts, which break down bone to release calcium into the blood stream.

Detailed explanation-4: -At the bone, PTH inhibits osteoblast activity and stimulates osteoclast activity leading to bone breakdown and calcium release. At the kidneys, PTH increases calcium reabsorption and blocks phosphate reabsorption from the tubules. PTH also acts at the kidneys to stimulate the formation of vitamin D.

Detailed explanation-5: -How do hormones from the thyroid and parathyroid regulate the calcium concentration of the blood? Calcitonin raises the blood calcium and parathormone lowers the blood calcium level.