PUMPA - SMART LEARNING
எங்கள் ஆசிரியர்களுடன் 1-ஆன்-1 ஆலோசனை நேரத்தைப் பெறுங்கள். டாப்பர் ஆவதற்கு நாங்கள் பயிற்சி அளிப்போம்
Book Free DemoThe parathyroid glands consist of four small and separate oval bodies located on the posterior surface of the lobes of the thyroid gland.
Posterior view of parathyroid glands
The cells of the parathyroid glands are arranged in a compact mass and are of two types:
1. Small chief cells or principal cells
2. Large oxyphil cells or eosinophil cells
Oxyphil and chief cells
The chief cells of the parathyroid gland secrete a hormone called Parathyroid Hormone (PTH) or parathormone. It is also called Collip's hormone, which is named after the name of its discoverer.
Functions of parathormone:
- The parathormoneregulates the calcium and phosphorous metabolism in the body. PTH acts on bones, kidneys and intestines to maintain the levels of calcium in the blood.
- PTHinhibits the collagen synthesis by osteoblasts and bone resorption by osteoclasts.
Parathyroid Dysfunction:
1. Hypoparathyroidism:
Decreased secretion of parathyroid hormone (PTH) can be caused due to a deficiency of PTH or the removal of the parathyroid gland during thyroidectomy (removal of the thyroid gland).
Hypoparathyroidism causes the lowering of calcium in the blood, which increases the excitability of nerves and muscles. This causes muscle cramps and convulsions. Sustained contractions of the muscles of the larynx, face, hands and feet are observed. The disorder is called parathyroid tetany or muscle spasm.
There are also painful cramps of the muscles of the limb.
2. Hyperparathyroidism:
It is caused due to the excess of PTH, which draws more calcium from the bones. Hyperparathyroidism causes demineralisation, resulting in bending and softness of the bones. The condition thus leads to osteoporosis. An excess of PTH causes calcium to be deposited in the kidneys.
Parathyroid and Hyperparathyroid
Reference:
file:///C:/Users/divya/Downloads/Parathyroid_es.svg
https://upload.wikimedia.org/wikipedia/commons/b/b4/1814_The_Parathyroid_Glands.jpg
https://upload.wikimedia.org/wikipedia/commons/thumb/4/45/3D_Medical_Animation_still_shot_Hyperparathyroidism.jpg/1024px-3D_Medical_Animation_still_shot_Hyperparathyroidism.jpg
Register for free to see more content