About the Thyroid
Wed, 03/19/2008 - 18:43
The thyroid gland is one part of the endocrine system which is primarily responsible for the regulation of healthy hormones in the body. The thyroid gland is considered as one of the largest endocrine glands in the body. It weighs 2-3 grams in newborns and 18-60 grams in adults. It is found in the anterior part of the neck, lying around the larynx and the trachea. It reaches the posterior of the esophagus and the carotid sheath. It has a butterfly-shaped structure with two lobes which secrete hormones responsible for metabolism. If you can palpate your thyroid gland while swallowing, you can be predisposed to goiter or hyperthyroidism. The name thyroid came from the Greek word which means “shield”. This can be clearly understood based on the structure of the gland which has a double-lobed structure. The pituitary gland which is also considered as the “master gland” controls the thyroid.
In the microscopic view of the thyroid gland, it is composed of follicles that selectively absorb iodine from the blood in order to produce thyroid hormones. These said follicles contain protein that stores the iodine for future hormone production. About 25 percent of the iodine in the body is stored in the thyroid gland. That’s why, it is important to have an adequate intake of iodine to prevent any deviation of the normal functions of the thyroid.
How Does the Thyroid Works
As I have said earlier, the thyroid gland is responsible for the regulation of the metabolism of the body. This means that the thyroid secretes hormones that are responsible for burning the calories, fats and other nutrients used by our body for energy. The hormones secreted by the thyroid gland are the triiodothyronine (T3), thyroxine (T4) and the thyrocalcitonin which is responsible for the calcium reabsorption or breakdown.
T3 and T4 are the two primary hormones responsible for metabolism. The anterior pituitary gland signals the thyroid gland to secrete hormones. The thyroxine hormone signals the brain to increase metabolism especially in times of stress and cold weather. The body produces heat and energy to maintain homeostasis of the body. These hormones are very essential in order to perform activities in a day-to-day basis.
Another hormone secreted by the thyroid gland is the thyrocalcitonin. This additional hormone contributes to the regulation of blood calcium levels. Calcitonin is essential for people with hypercalcemia (high concentration of calcium in the blood) and osteoporosis. This hormone stimulates the movement of calcium from the bloodstream to the bones. Thyrocalcitonin is considered as an antagonist of the parathormone which is responsible for the regulation of calcium and phosphorus in the body.
Any alteration in the amount of hormones secreted by the thyroid gland will cause tremendous change in the body. An increase or decrease in the level of TSH in the body will cause hyperthyroidism or hypothyroidism. These disorders are critical and should ample amount of concern before complications occur. Hypothyroidism may manifest CNS depression namely lethargy, poor memory and even coma is possible. People with hypothyroidism have low metabolic rates which cause gain weight. But these people have poor appetite or anorexia. They are also intolerable to cold weather. That’s why; these people should be provided a warm environment and small frequent feeding with low caloric content. This disorder is due to decrease iodine intake, trauma or tumor. On the other hand, hyperthyroidism or Grave’s disease may manifest exophthalmia or protrusion of the eyes, weight loss but with a strong appetite. People with hyperthyroidism have heat intolerance so they should be provided a cool and calm environment. The central nervous system is stimulated so irritability, restlessness, insomnia and hallucination are apparent.