[Endocrinology] The parathyroid glands

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Physiology

The parathyroid glands synthesise parathyroid hormone (PTH) and secrete it into the blood stream. 
Parathyroid hormone is a small protein hormone which indirectly stimulates osteoclast activity within bone marrow.

Stimulated by: Decreased serum [Ca2+]
Inhibited by: Increased serum [Ca2+]
Output: Parathyroid hormone (PTH)

Osteoclasts break down bone, causing the release of ionic calcium (Ca2+) into the blood.
This increases serum levels of calcium.

 

Hormones

• Parathyroid hormone (PTH)

 

Pathophysiology

Parathyroid diseases

• Hyperparathyroidism is a pathological state caused by excessive PTH in the blood.
• Hypoparathyroidism is a pathological state caused by insufficient PTH in the blood.
• Pseudohypoparathyroidism is a pathological state caused by insensitivity to PTH.