Thyroid hormones are Tyrosine based hormones that require triidothyronine (T3) and Thyroxine (T4). These hormones are produced by the thyroid gland. The Thyroid gland is primarily known for the regulation of metabolism, as well as proper production of T3 and T4. Iodine is the main component that is needed. Dysfunction of Iodine can lead to decreased production of T3 and T4, resulting in enlarged thyroid tissue and even lead to thyroid diseases.
It is made up of two types of cells: follicular cells and parafollicular cells, although most of the thyroid tissue is made of the follicular cells. These cells secrete iodine-containing hormones call thyroxin (T4) and triiodothyronine (T3). The reason for this is because the thyroid needs iodine to produce the hormones. The parafollicular cells secrete the hormone calcitonin. The thyroid plays an important role in regulating the body’s metabolism and calcium balance.
The thyroid gland is located in the anterior, middle portion of the neck. Many of the bodies’ hormones come from the thyroid. According to Porth 2011, “the thyroid hormone increases the metabolism and protein synthesis in nearly all of the tissues of the body.” (p. 784). When these hormones are not regulated, a thyroid disorder develops such as hypothyroidism and hyperthyroidism. Hypothyroidism develops when the thyroid gland does not produce enough of certain hormones.
The hypothalamus is a small portion of the brain that has both nervous system and endocrine functions (McKinley, 2013). One of it’s main functions is to connect the nervous system to the endocrine system (McKinley, 2013). Hypothalamic regulatory hormones are produced in the hypothalamus and regulate the secretion of hormones that are produced by the anterior pituitary (McKinley, 2013). One of the hormones produced by the anterior pituitary is thyroid-stimulating hormone (TSH) which stimulates the thyroid gland to produce thyroid hormone (McKinley, 2013). Graves’ disease is an autoimmune disorder in which the body overproduces thyroid hormone (Yeung, 2013).
The 2 main thyroid hormones are T3 (triiodothyronine) and T4 (thyroxin). The amount of thyroid hormones secreted is controlled by another hormone, called thyroid stimulating hormone (TSH), which is released from the pituitary gland in your head ("How Your Thyroid Works"). Thyroid hormones act throughout the body, influencing metabolism, growth and development, and body temperature. During infancy and childhood, adequate thyroid hormone is crucial for brain development (Tree, 2013). The thyroid gland also makes the hormone calcitonin, which is involved in calcium metabolism and stimulating bone cells to add c... ... middle of paper ... ...e feedback loop keeps track of the thyroid hormones so that when the levels of the of hormones increase, they prevent the release of both thyrotropin-releasing- hormone (TRH) from the hypothalamus and thyroid stimulating hormone (TSH) from the pituitary gland ("You & Your Hormones," 2013).
In healthy an individual, the thyroid gland produces thyroid hormones T3 and T4 through a series of steps. Iodide is carry into the thyroid follicular cell from the blood stream by symporters. The iodide is transported into the cell against it concentration gradient, using Na+ concentration gradient as an energy source. The iodide in the follicular cell is activated through oxidation by thyroperoxidase (TPO). The active iodide is passively transported into the colloid through an iodide channel on the luminal side of the follicular cell down its concentration gradient.
The thyroid gland is located in the lower part of the neck, below the Adam's apple, wrapped around the trachea. It has the shape of a butterfly with two lobes attached to one another by a middle part called the isthmus. The thyroid uses iodine, a mineral found in some foods and in iodized salt, to make its hormones. The two most important thyroid hormones are thyroxine (T4) and triiodothyronine (T3). The thyroid gland also makes the hormone calcitonin, which is involved in calcium metabolism and stimulating bone cells to add calcium to bone.
There are multiple diseases associated with hyperthyroidism, Graves’ disease, excessive intake of iodine and mulitnodular goiter. The function of the endocrine gland is to secrete hormones in the internal body. For example, thyrotropin-releasing hormone is released by the hypothalamus to the anterior pituitary gland, which releases thyroid-stimulating hormone (TSH) and binds to TSH receptors on thyroid gland. This leads to the production of triiodothyronine (T3); thyroxine (T4). Certain pathologies increase the production of T3 and T4 leads to hyperthyroidism.
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.
Within the hypothalamic-pituitary-thyroid axis, thyrotrophin-releasing hormone (TRH) stimulates the secretion of thyroid stimulating hormone (TSH) from the anterior pituitary . TSH then acts on thyroid gland which releases the iodine dependent hormone thyroxine (T4) and triiodothyroxine (T3) to control physiological functions such as metabolism, heart rate, blood pressure, and body temperature . Etiology There are several risk factors for TC including patient history, family history, genetic factors, age, gender, and environmental factors such as ionizing radiation exposure and iodine deficiency [5, 6]. During the first 20 years of a person’s life, exposures to ionizing radiations can be particularly damaging to the thyroid gland. These radiations generate free water or oxygen radicals which directly... ... middle of paper ... ... the initial drug effects wane down over time as alternate pathways compensate.