calcitonin
Học thuậtThân thiện
Definition
- Noun:
- A hormone produced by the thyroid gland: Calcitonin is a peptide hormone secreted by the C-cells of the thyroid gland. Its primary physiological role is to help regulate calcium and phosphate levels in the blood.
- A calcium-lowering agent: The defining action of calcitonin is to decrease the concentration of calcium in the blood plasma. It achieves this primarily by inhibiting the activity of osteoclasts, the cells that break down bone tissue and release calcium into the bloodstream.
Usage Examples
- Noun:
- The doctor explained that calcitonin acts as a counterbalance to parathyroid hormone in calcium homeostasis.
- A synthetic form of calcitonin is sometimes prescribed to treat conditions like Paget's disease of bone.
- The secretion of calcitonin increases when blood calcium levels are high.
Advanced Usage
- Therapeutic Use: In clinical medicine, calcitonin (often derived from salmon, which is more potent in humans) is used as a drug to treat bone disorders. Its action inhibits bone resorption.
- Calcitonin therapy can help reduce bone pain and lower elevated alkaline phosphatase levels in patients.
Variants and Related Words
- Thyrocalcitonin (n): An older, synonymous term for calcitonin, emphasizing its thyroid origin.
- Hypocalcemic hormone (n): A descriptive term highlighting its effect of lowering blood calcium.
Synonyms
- Thyrocalcitonin (n): The full technical name.
- Calcium-regulating hormone (n): A broader descriptive term.
Related Concepts (Not Phrasal Verbs or Idioms)
- Bone resorption (n): The process of bone breakdown that calcitonin inhibits.
- Osteoclast (n): The bone cell whose activity is suppressed by calcitonin.
- Parathyroid hormone (PTH) (n): The antagonistic hormone that raises blood calcium levels, opposing calcitonin's action.
Noun
- thyroid hormone that tends to lower the level of calcium in the blood plasma and inhibit resorption of bone