Congenital Hypothyroidism

Week 3 – LOM Assignment The thyroid is responsible for taking iodine and converting it into thyroid hormones which are released into the blood stream and transported throughout the body where they control metabolism.1 The thyroid is a vital part of the human body as every cell in the body depends on it for metabolic regulation. Too much or too little thyroid hormone secretion can result in hyperthyroidism or hypothyroidism. Hyperthyroidism is caused when the thyroid secretes too many thyroid hormones. Hyperthyroidism causes a rapid heart rate, elevated blood pressure and tremors. Other symptoms include increased nervousness, inability to concentrate, weakness, restlessness, difficulty sleeping, frequent bowel movements, weight loss and irregular

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

Incidentally, there are actually two compounds made in the thyroid that are called thyroid hormone. The most abundant is T4, also known as thyroxine, which is then converted to T3, or triiodothyronine. T3 is the active form that produces the effects on metabolism.

To do this, the researchers exposed a second group of adult quail to the same hearing-damaging sound as the first and then injected them with radiolabeled thymidine. This allowed researchers to use autoradiography that produce low levels of background issues as well as being able to see 10 to 20 grains over red blood cells. The control birds were still given the injections, however, they were not exposed to the sound. The experimental group experienced the same pattern of damage as the birds in the previous experiment and thymidine was seen over hair cells and support cells in the damaged area. There was no thymidine observed outside of the damaged area. The transition zone of the basilar membrane, where tall and short hair cells are integrated, it seemed that the short cells were more often labeled than the tall cells. Tall cells do not lack the afferent auditory-nerve fiber innervation that is seen in short cells making them a more useful candidate for labeling. The researchers failed to identify location and mechanism of the activation of the precursor cells but remained hopeful that there may exist a way to restore inner ear sensory losses that are caused from injury of hair

Commonly, problems with the thyroid involve an abnormal production level of these hormones. It is called hyperthyroidism if there the thyroid hormones are overproduced, and this can cause things like Graves’ disease, Toxic adenomas, and subacute thyroiditis (7). Hypothyroidism is the underproduction of the hormones which can be caused by an inflamed thyroid, iodine deficiency, a non-functioning thyroid gland and more. Hypothyroidism is especially dangerous in infants and newborns as the lack of these thyroid hormones can lead to mental retardation and dwarfism (7). However, in humans hypothyroidism can be caused by things such as a pituitary disorder, a defective thyroid or a lack of the gland completely. (7)

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

Starting during prenatal development and continuing throughout life, thyroid hormones pay an important role in the cardiovascular system, the relationship in which has been seen to change in the case of thyroid dysfunction. The relationship between the heart and the thyroid has been demonstrated through a series of experimental and clinical studies and the results determined that in the case of hypothyroidism parameters such as blood volume and heart rate have been seen to decrease from 100% and 72-84bpm to 84.5 % and 60-80bpm respectively. The regular measurements of both the patients cardiac output and systemic vascular resistance have also been seen to change, shifting from 4.0-6.0 L/min and 1500-1700 dyn·sec/cm-5 to <4.5 L/min and 2100-2700

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

Hypothyroidism is defined by a reduction in the release of the main thyroid hormones, Thyroxine (T4) and Triiodothyronine (T3). These hormones are essential in the homeostatic maintenance in the area of metabolic function (PetMD, 2017). This condition is not life-threatening and is usually very inexpensive to treat (WebMD, 2017). While there are many causes for hypothyroidism, the common causes include shrinking of the thyroid gland, tumors or cancer of the thyroid, congenital disease, iodine deficiency, and sometimes even an autoimmune issue where the body attacks its own thyroid. The risk for this disease appears to increase when the animal is spayed or neutered for currently unknown reasons (WebMD 2016). This condition is most

Thyroid hormone production is regulated by a hormone called thyroid stimulating hormone and it is made in the brain by the pituitary gland. Since it occurs in the thyroid gland, thyroid hormones affect metabolism, brain development, body temperature, skin dryness, and it speeds up many of the body’s functions. The

These hormones have a critical role in cell differentiation during development and help maintain thermogenic and metabolic homeostasis in the adults.12 Thyroid disorders are highly prevalent in the population and mostly affect women in childbearing age.13 In pregnancy, thyroid gland displays mild to moderate enlargement because of increased physiological demands. Thyroid function is altered by 4 factors in pregnancy: i) the transient increase in human chorionic gonadotropin (hCG) during the first trimester, which cross-reacts with thyroid-stimulating hormone (TSH) receptor; ii) the estrogen-induced rise in thyroxine-binding globulin (TBG) which is the major transport protein for thyroid hormone; iii) increased autoimmunity; and iv) increased urinary iodide clearance, which can cause impaired thyroid hormone production in areas of low iodine supply.12,14-17 Consequently, the levels of both T3 and T4, the major hormones released by the thyroid, increase by ~50% and serum TSH levels decrease in the first trimester and increase in the second and third

Purpose: The purpose of this study was to determine if oncomodulin is necessary for cochlear development as well as cochlear functioning. Looking at oncomodulin is a relatively new topic in the scientific community and therefore this research is applicable as scientists are trying to figure out the purpose behind it being located almost solely in the outer hair cells of the cochlea. In order to better understand the function of oncomodulin, this study depleted hair cells of oncomodulin to see how cochlear function was affected.

Stimulate the secretion of thyroid hormones from the thyroid gland by binding to a receptor on the surface of the cells of the thyroid (G protein -coupled receptors).TSH is stimulated by TRH hormone of the hypothalamus and is inhibited by Somatostatin hormone, as well as by thyroid hormones in a negative feedback loop.