Parathyroide hormone and bone disease

1. Parathyroid hormone
and bone diseases

2. Out lines:
 Calcium
Calcium absorption
Disorders of Parathyroid Hormone

3. calcium:
 One of the most important elements found in the body.
 Structural component in bone and teeth. .
 99% stored in the bone
 The average content of calcium in adults is 1 kg

4. Calcium absorption:
refers to the transport of the calcium that received from
food, from intestine into the blood.

5. Substances that increased
calcium in blood:
1. active form of Vitamin D.
2. Parathyroid hormone.

6. 1. Active form of vitamin D
 Found two types from vitamin D:
 vitamin D2 (ergocalciferol)
 vitamin D3 ( cholecalciferol)
 Found two sources for vitamin D in human body:
 From Diet.
 From Dermal synthesis of vitamin D from cholesterol is dependent on
sun light (specifically UVB radiation).
 Vitamin D from the diet or dermal synthesis form's sun light is biologically
inactive
 activation requires enzymatic conversion (hydroxylation) in the liver and
kidney and activation by parathyroid hormone.
 The active form of vitamin D absorption calcium from intestine.

8. 2. Parathyroid hormone
 Parathyroid hormone (PTH) is a hormone
secreted by the parathyroid glands.
 increase of Calcium concentration in plasma
by:
1. Activation of vitamin Dз synthesis and
increase of absorption in the intestine

9. Effect PTH on Activation of vitamin D

10. 2. Increase of calcium reabsorption in kidneys

11. 3. Releasing of Са by bones (osteoclasts)

13. Disorders of Parathyroid Hormone
Hyperparathyroidism
Hypo parathyroidism

14.  metabolic disorder with excessive secretion of
Parathyroid hormone (PTH).
 can be characterized into primary, secondary, and
tertiary.
 Resulting in high levels of calcium in the blood
(hypercalcemia), which can cause a variety of
health problems.
 causing bone furcating and bone pain.
Hyperparathyroidism

15.  deficiency or absence of PTH
secretion.
 metabolic disorder characterized by
low serum calcium.
 Causes decrease in effective vitamin
D in body.
Hypo parathyroidism