Approximately 20 million Americans are currently suffering from thyroid disease. This common, yet subtle disease can be have an immense impact on one’s health and lifestyle. I chose to research thyroid disease because I have had blood tests done in speculation of this disease because of the similar symptoms I was experiencing. Although I do not have thyroid disease, I am curious about how it affects the body and why this disease often goes undiagnosed. This system involving the thyroid is crucial in regulating the body’s hormones and keeping them.
The thyroid is a butterfly-shaped gland that is located anteriorly in the lower neck. It is an endocrine gland made of two vertically elongated lobes that are connected by the isthmus. Each lobe is between twelve and fifteen millimeters long. The thyroid is coated with a fine fibrous sheath and is surrounded by cartilage and muscles in the neck such as the sternomastoid muscle. Superior to the collarbone, the thyroid is situated next to the larynx and trachea. When swallowing, the thyroid moves because it is rigidly attached to the trachea.
On the posterior side of the each lobe, there are two parathyroid glands, which are responsible for assisting in calcium regulation. The weight of the thyroid can vary from twenty to fifty grams in adults. Typically, women have a slightly heavier thyroid and it expands during menstruation and pregnancy. Inside the two lobes, the thyroid is made of thyroid tissue that contains many smaller lobules and that are linked with connective tissues. Each lobule contains a large number of follicles that store droplets of the thyroid hormones.
The thyroid is a crucial part of the endocrine system that is responsible for growth and development in the body. It controls the rate of activities in the body and determines how fast the heart beats and how fast calories are burned. Three hormones are produced by the thyroid that are responsible for this regulation of metabolism: Triiodothyronine (T3), Tetraiodothyronine or Thyroxine (T4), and Calcitonin. The T3 and T4 hormones are the most important in controlling the rate of activities, and are formed in the cells of the thyroid. In both of these hormones, the element iodine is a major factor. In fact, these hormones are named for how many atoms of iodine they receive-- T3 gets three atoms of iodine and T4 gets four.
Iodine plays a significant role in thyroid metabolism, and it is even more imperative because the body cannot generate iodine; it must be obtained through food intake. When food reaches the intestine during digestion, the iodine is extracted from and released into the bloodstream. The iodine travels through the blood to the thyroid, where the thyroid follicles absorb the iodine. Once the iodide ions are absorbed, they are constructed into the thyroid hormones or stored for future use. In fact, about twenty-five percent of the body’s iodine is stored in the thyroid. When the T3 and T4 hormones...