Disorders Of Endocrine Control Of Growth And Metabolism

Decent Essays

Symptomatology, Diagnosis & Pathology 1B
Assessment Task
Q1) Disorders of Endocrine Control of Growth and Metabolism (10 marks)
i.When testing for hypothyroidism, why is the free T4 level an important measurement? Predict what the TSH and T4 test results would indicate in someone with primary hypothyroidism. Explain your answer. (100 – 200 words, 5 marks)
Hashimoto thyroiditis is a common disease caused by hypothyroidism. The immune system cells attack the thyroid gland, causing inflammation and eventually destruction of the gland. This reduces the thyroids ability to make hormones. These hormones are known as thyroxine (T4) and tri-iodothyronine (T3) (Better health channel 2015).
In order to evaluate thyroid function and diagnose thyroid diseases such as hyperthyroidism or hypothyroidism, the free thyroxine (free T4) lab test is performed usually after discovering that the thyroid stimulating hormone (TSH) level is abnormal (Porth C 2014 p.1288)
T4 and T3 usually circulate in the blood bound to protein and only a small percentage is free (not bound). Blood tests can measure total T4, free T4, total T3, or free T3. The total T4 can be affected by the amount of protein available to bind to the hormone. The free T4 test is thought to be a more accurate reflection of thyroid hormone function, as it is not affected by protein and is the active form of thyroxine (AACC 2015).
In general, high free T4 results may indicate an overactive thyroid gland (hyperthyroidism), and low free

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