Wednesday, February 24, 2010

Thyroid Gland

  • Is a butterfly-shaped mass of tissues located in the anterior part of the neck.
  • It is about 2 inches long, with two lobes joined by strands of thyroid tissues called the isthmus.
  • Thyroid gland has a rich blood supply. It fact, it has been estimated that about 4 to 5 liter (some 8.5 to 10.5 pints) of blood pass through the gland every hour.
  • Thyroid gland secretes three hormones: thyroxine, triiodothyronine and calcitonin.
  • The function of thyroxin (T4) and triiodothyronine (T3) are as follows:
1. Controls the rate of metabolism in the body: how cell use glucose and oxygen to
produce heat and energy.
2. Stimulates protein synthesis and thus helps in tissue growth.
3. Stimulates the breakdown of liver glycogen

  • Calcitonin controls the calcium ion concentration in the body by maintaining a proper calcium level in the bloodstream.
  • Approximately 99% of calcium stored in bones. Calcium is necessary for blood clotting, holding cell together and neuromuscular functions.
  • Proper secretion of calcitonin into the bloodstream prevents hypercalcemia, a harmful rise in the blood calcium level.

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