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Preksha Dhyana
other organ of the body with the possible exception of the adrenal gland; e.g., it receives four times as much blood as do the kidneys. This gland is innervated by sympathetic and parasympathetic nerves.
Its most astonishing feature is its ability to take up and concentratel arge amounts of iodine which, within the gland, may be 50 to 300 times more than in the bloodplasma. Iodine ions are very effectively removed from the circulating blood by an active transport mechanism (an iodide pump). Iodine is used to produce hormones which regulate protein-, carbohydrate-, and fat-metabolism. They are essential for growth and mental development. Another hormone which does not contain iodine is concerned in the body's calcium metabolism.*
The rate of release of thyroid hormones is principally regulated by the thyrotrophic hormone-TSH-of the anterior pituitary. The role of thyroid hormones lies in growth and development.
Thyroxine is the main secretion of this gland. It is a gelatenous substance. Besides a large percentage of iodine, it also contains iron, arsenic and phosphorous-iron for the general system and to aid in the electric energy and conductivity of the system; phophorous for the nerve and brain centre; and arsenic for the skin. The hormone is the builder of the nerve and brain tissue. Tri-iodo-thyronine is the other hormone which regulates the metabolic rate of the body.
Thyroid gland is essentially an energy producing organ and its output is the controller of the rate of metabolism or the speed of living. Any disturbance in the thyroid secretion in quantity, i.e., too much or too little, or in quality, i.e., an abnormal change in the chemical composition, produces serious results. Thyroid is very closely related to other glands. It is the other great link between the brain and the organs of generation; and its acceleration is necessary to give balance to the brain.
*The body has a double system for regulating calcium-metabolism. Calcitonin-recently discovered hormone from the thyroid-seems to act as a short-term regulator, preventing acute excess of calcium in the body-fiuids, while the parathyroid hormone sets the long-term level of calcium ions in them.
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