Review of the Anatomy of Thyroid and Parathyroid and their Functions The thyroid is a gland shaped like a butterfly and located in front of the trachea (windpipe), right below the larynx (voice box). The thyroid gland traps iodine from dark and green leafy vegetables as well as the salt we eat from our foods to synthesis two hormones labelled T3 and T4 as in Triiodothyronine and Thyroxine respectively. These hormones regulate the body’s metabolism and other functions relating to cardiovascular and respiratory activities. The parathyroid glands are four tiny glands found right behind the thyroid glands. The parathyroid glands produce parathyroid hormones, a substance that regulates calcium composition in the blood. The Physiology of the Thyroid Gland The production of thyroid hormones by the thyroid gland is triggered by the hypothalamus releasing TRH- thyroid releasing hormones into the pituitary glands. The pituitary gland in return releases TSH- thyroid stimulating hormones into the thyroid gland where they bind the iodine trapped by the follicular cells of the thyroid and tyrosine to form thyroglobulin which is a unique protein produced by the thyroid. This thyroglobulin houses the two thyroid hormones namely triiodothyronine and thyroxine, thus T3 and T4 respectively. T3 or triiodothyronine is the active hormone between the two and is released into the tissues for metabolism purposes whiles the T4 or the thyroxine remains inactive and stored as thyroglobulin until it is bound with an enzyme called deiodinase before it can be converted to T3 for the use of tissues in metabolic processes. T3 and T4 are also responsible for regulating cardiovascular and respiratory rates. Defects of Thyroid Glands 1) Thyroid cancer(thyroiditis) which can affect people of all ages and its presented with swollen thyroid gland 2) Autoimmune thyroid defect (Hashimoto’s disease) where the immune system attacks the thyroid gland resulting in excess thyroid hormone production 3) Goiter which is the abnormal enlargement of the thyroid gland usually associated with lack of iodine Physiology of the Parathyroid Gland The parathyroid glands synthesize parathyroid hormones. Parathyroid hormones inhibit osteoblast activities and stimulate osteoclast activities that pave way for bone breakdown and calcium release. The parathyroid glands’ function mainly is to ensure serum calcium homeostasis Hyperthyroidism Hyperthyroidism results in a situation where the thyroid hormone produces excessive thyroid hormone than required. This condition may result in an over active metabolic rate, and higher than normal cardiovascular and respiratory rates Symptoms of hyperthyroidism may include; irritability, insomnia, weight loss despite good appetite, heat loss, heat intolerance, diarrhea, heart racing among others Causes of hyperthyroidism 1) Grave’s disease, an autoimmune disorder in which the immune system attacks the thyroid and causes it to produce excessive hormone 2) Thyroid nodules, they are growths on the thyroid 3) Thyroiditis, inflammation of the thyroid gland 4) Excessive iodine 5) Excessive thyroid medications Treatment of hyperthyroidism 1) Anti-thyroid medication 2) Radioactive iodine treatment with subsequent hormone replacement 3) Surgery Hypothyroidism Hypothyroidism results in a situation where the thyroid gland produces inadequate thyroid gland needed by the body to carry out metabolic activities. This condition may result in a slow metabolic rate, lower than required respiratory and cardiovascular rates among others. Symptoms of hypothyroidism may include; fatigue, weight gain, cold intolerance, slow heart rate, heavy menstrual bleeding, constipation among others. Causes of Hypothyroidism 1) Hashimoto’s disease, an autoimmune defect of the thyroid that causes an initial leakage and excess hormone production, and subsequently , over time, the inflammation prevents the thyroid from producing enough hormone 2) Iodine deficiency Treatment of hypothyroidism 1) Treatment consist of thyroid hormone replacements through medication 2) Reversing the signs and symptoms of hypothyroidism Lab Values to Diagnose Pathology of Thyroid Gland 1) Anti-thyroid microsomal antibody test, conducted when thyroid disorder is autoimmune (Hashimoto’s and Grave’s diseases) 2) Anti-thyroglobulin antibodies test performed when thyroiditis is suspected 3) RAIU-Test of thyroid function, measures the amount of Radioactive Iodine accumulation in the thyroid Work Cited 1) www.cancer.gov, as the source and/or the image creator 2) https://thyroidresearchjournal.biomedcentral.com/articles 3) https://en.wikipedia.org/wiki/Thyroid_disease .
