Скачать с ютуб The Thyroid Gland | Complete Anatomy в хорошем качестве

The Thyroid Gland | Complete Anatomy

Subscribe to 3D4Medical channel to learn more about the human body: https://goo.gl/8k5KzR The thyroid gland is a small, butterfly-shaped organ that can be found at the front of the neck. It lies at the level between the fifth cervical vertebrae and the 1st thoracic vertebrae. It is highly vascular and weighs about 25g. It may be small but it is very important, as it secretes hormones that act on several parts of your body, affecting them in different ways. The thyroid gland secretes Calcitonin, as well as T3 and T4, which are commonly known as the thyroid hormones. Calcitonin regulates bone growth while the thyroid hormones regulate growth and development in young people, and play an important role in maintaining a healthy metabolism. An excess of thyroid hormones results in overstimulation of the sympathetic nervous system, leading to an increased heart rate, palpitations, hyperventilation, tremors, heat intolerance and angina. A deficiency will result in a reduced heart rate, tiredness, cold intolerance and so on. Thyroid hormones also have an important role to play in glucose metabolism; they stimulate digestive tract motility to aid in absorption, increase the production of glucose by gluconeogenesis and glycogenolysis, and enhance the uptake of glucose into cells. Therefore, those suffering from hyperthyroidism commonly experience weight loss, and increased appetite, while those with hypothyroidism will experience weight gain and constipation. Thyroid hormones also play an important role in maintaining normal sleep and sexual function. The secretion of the thyroid hormone from the thyroid gland is regulated by other endocrine structures in the brain, the hypothalamus and the pituitary gland. The three structures work through a feedback system which is determined by the amount of thyroid hormone in the bloodstream. When the levels of thyroid hormone are low, the hypothalamus picks up the signal and secretes a precursor hormone TRH. TRH stimulates the secretion of Thyroid stimulating hormone or TSH from the pituitary gland. TSH stimulates the secretion of Thyroid hormone which goes on to affect the metabolism of the heart, liver, kidney, muscles and reproductive organs. On the other hand, When thyroid hormone levels are high there is a reduction in the amount of TSH and thyroid hormone secreted. And this, in turn reduces its effects on digestive and reproductive systems, the bones, muscles,as well as the cardiovascular and respiratory systems. Download Complete Anatomy on Mac: https://itunes.apple.com/us/app/compl... Download Complete Anatomy on iOS: https://geo.itunes.apple.com/us/app/c... Download Complete Anatomy on Windows: http://clkuk.tradedoubler.com/click?p...