Effects Of Thyroid Hormones On Cortical Neuron Dendritic Outgrowth And Cell Viability

Hashimoto’s Thyroiditis, also called Hashimoto’s disease is an autoimmune disease in which the body’s immune system attacks the thyroid gland. It was named for the Japanese surgeon who discovered it in 1912 The thyroid is a small butterfly shaped gland in the front of the neck. The thyroid makes hormones called T3 and T4. These hormones regulate metabolism. The thyroid is controlled by hormones of the pituitary gland, which is also called the “master gland.” It is a pea-sized gland located in the base of the brain which, among others, makes thyroid stimulating hormone, or TSH. TSH stimulates the thyroid to make thyroid hormone. With Hashimoto’s disease, the thyroid cells are damaged resulting in the inability to make enough thyroid

Laboratory Report/ Miranda Tefft/ Homeostatic Imbalances of Thyroid Function/ Aline Potvin/ 11.18.2014/ Page [2] of [3]

pituitary is not creating as much TSH. This would cause the Thyroid to stop producing T4

TSH not only stimulates the thyroid gland to churn out more hormones. If in excess, can cause overwhelming cell growth and division to result in goiter.

Thyroid research came about after a paper published in 1850, written by Thomas Curling talking about two girls who had severe malformation and were placed in an idiot asylum. One of the girls, 10, could not walk or talk very well; the other, 6 months, “was plump but had a marked idiotic expression, a large face with a small

Normally, the thyroid gets its production orders through another chemical called thyroid-stimulating hormone (TSH), released by the pituitary gland in the brain. But in Graves' disease, a malfunction in the body's immune system releases abnormal antibodies that mimic TSH. Spurred by these false signals to produce, the thyroid's hormone factories work overtime and exceed their normal quota.

The thyroid gland is the gland that makes and stores hormones that help regulate the heart rate, blood pressure, body temperature, and metabolism. Thyroid hormones are essential for the function of every cell in the body. They help regulate growth and the rate of chemical reactions in the body. Thyroid hormones also help children grow and develop. 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

Like many other organs and cells in the body, the heart is affected by decrease secretion of thyroid hormone. The heart mainly relies of T3, for it is the hormone that is transported into the myocytes. T3 binds to thyroid hormone receptors, which is the start of its many cellular actions. The activation of T3 in the myocytes is responsible for systemic vascular resistance, heart rate, contractility, and blood volume. In primary overt hypothyroidism, there is a hyposecretion of T4 and T3, which affects the cardiovascular hemodynamics. If there is not a sufficient amount of T4 to convert to T3, then there is not enough T3 available for the myocytes to carry out their cellular reaction. As a result, there is a decrease in cardiac output and cardiac contractility with an increase in peripheral vascular resistance. People with cardiovascular dysfunction due to primary overt hypothyroidism typically present with bradycardia, hypertension, dyspnea on exertion, and edema. However, most of the cardiovascular dysfunction responds well with thyroxine replacement therapy (Danzi;

The thyroid gland is the gland that makes and stores hormones that help regulate the heart rate, blood pressure, body temperature, and metabolism. Thyroid hormones are essential for the function of every cell in the body. They help regulate growth and the rate of chemical reactions in the body. Thyroid hormones also help children grow and develop. 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

Central Idea: The thyroid controls so many things in your body and if not well taken care of can cause major damage to a person or their life.

The thyroid stimulating hormone receptors are G-protein linked and are found extracellularly in the thyroid glands. When activated, synthesis of hormonally active iodothyronines T3 (triiodothyronine) and T4 (thyroxine) begins (Park and Chatterjee, 2005). This process begins with iodide is transported into the thyroid gland by the sodium iodide symporter found in the membrane of thyroid follicular cells (Park and Chatterjee, 2005). The iodotyrosine residues monoiodotyrosine and diiodotyrosine are then formed through iodine organification where the iodide is oxidised using hydrogen peroxide and then bound to tyrosine in the thyroglobulin (Park and Chatterjee, 2005). The residues then bind together to form the hormonally active iodothyronines aforementioned (Park and Chatterjee, 2005). Many catalytic enzymes mediate this process and are needed to ensure proper thyroid hormone synthesis. Failure in any steps of the synthesis process leads dyshormonogenesis and could be the result of genetic defects. Adequate synthesis of active thyroid hormone is necessary for the regulation of many developmental processes (Richter, C. et al.,

Thyroid Function Tests: The thyroid’s job is to make thyroid hormones, which are secreted into the blood and the carried to every tissue in the body. The major thyroid hormone secreted by the thyroid gland is thyroxine, also called T4 as it contains four iodine atoms. T4 is converted to T3 (triodothyronine) by removal of iodine atom. It occurs mainly in liver and in brain. The amount of T4 produced is controlled by another hormone which is made in the pituitary gland located at the base of brain, called thyroid stimulating hormone (TSH). The amount of TSH is in the blood depends on the amount of T4 that the pituitary sees. If the pituitary sees very little T4, then it produces more TSH to tell thyroid gland to produce more T4.When T4 in the bloodstream goes above a certain level, the pituitary’s production of TSH is shut off. The thyroid and pituitary act like heater and a thermostat. If it’s cold the thermostat reads the temperature and turns on the heater. Thus, the thyroid and pituitary, like heater turn on and off. T4 and T3 circulate almost entirely proteins, and when these proteins change their level in the blood, there is change in T4 and T3 levels.

The thyroid gland is found in the front of the neck and produces two main hormones. The hormones are called thuroxine (T4) and Triiodothyronine (T3). Together these hormones regulate the body’s metabolism by increasing energy use in cells, regulate growth and development, help to maintain body temperature and aid in oxygen consumption. These two hormones are regulated by hormones produced by the hypothalamus and pituitary gland. The hypothalamus senses changes in body’s metabolic rate and releases a hormone known as thyropin-releasing hormone (TRH). This hormone then flows through connecting vessels to the pituitary gland which signals it to release another hormone. This hormone is known as thyroid-stimulating hormone (TSH). TSH then makes

Congenital disorders with intellectual disability (ID) constitute a particularly significant medical problem because of the high prevalence and life-long care that patients will need. The extreme genetic heterogeneity of ID is a major problem for pre- and postnatal diagnosis. In some cases, however, early detection of a mutation may be important to prevent the manifestation of the handicap (Avbelj et al. 2007). Congenital hypothyroidism (CH) is one of the most frequent causes of preventable ID, which can be averted by administering thyroid hormone in early postnatal life. This is achieved by newborn screening detection.

The central effects of hyperthyroidism are most pronounced in development. Cerebral circulation and oxygen consumption elevate. "In hyperthyroidism, Beta-adrenergic binding sites in the cerebral cortex increases and gamma-aminobutyric acid (GABA) binding sites are decreases." (Bucurescu,2014). Brain levels of serotonin, 5-hydroxyindoleacetic acid, and substance P are altered. Native pain sensitivity and number of opiate receptors are increases. Thyroid hormones affect myelination, therefore increased levels lead to oxidative damage to the myelin membrane and/or the oligodendroglial cells. The neurological manifestation is primarily due to the effect of thyroid hormones on other neurotransmitters, hormones, and generalized increased basal metabolic rate. Some of the neurological symptoms are: