Chapter 1 Introduction to Pathophysiology; Cellular Responses to Stress, Injury, and Aging
Section 10 Abnormal Calcium Deposition
Zoë Soon
Two additional tissue abnormalities involve the inappropriate deposition of calcium salts:
| Dystrophic calcification | Calcium deposits form on injured or dying tissue – for example, on atherosclerotic plaques in blood vessels or on tuberculosis lesions (Ghon foci). The tissue becomes stiffer and less functional. This is the more common form. Example: calcific aortic stenosis – narrowing of the aorta due to calcium deposits on atherosclerotic plaque, making the vessel wall rigid and obstructing blood flow. |
| Metastatic calcification | Calcium deposits form on normal tissue. This is much rarer and typically caused by hypercalcemia (excess calcium in the blood). Tissues commonly affected include the lungs, renal tubules, and blood vessels. The most common cause of hypercalcemia is hyperparathyroidism – a condition in which the parathyroid gland produces too much parathyroid hormone (PTH), driving calcium out of the bones and into the blood. Prolonged immobilization can also cause hypercalcemia. |
