Adrenal and Thyroid

Questions: Task 11. What are the principle hormones produced and secreted by the adrenal (medulla) gland? Include the synthesis, transport, and regulation of these hormones. 2. What specific assays are performed in a clinical laboratory to assess adrenal function? Include the simulation tests and what they assess.Task 21. What are the functions of the thyroid hormones in terms of target tissue and target tissue response?2. Compare and contrast hyperthyroidism and hypothyroidism hormones levels. 3. What are the healthy reference intervals for T3, T4, TSH, and thyroglobulin? 4. What lab assays are used to assess thyroid function and dysfunction? What are the principles of the reactions? 5. Compare and contrast the symptoms of hypothyroidism and hyperthyroidism. Answers: Task 1 1. The medulla of adrenal gland produces adrenaline (epinephrine) and noradrenaline (norepinephrine). Adrenaline and noradrenaline are synthesized from tyrosine and phenylalanine by chromaffin cells of the medulla. These hormones are directly secreted into the bloodstream. Through the circulatory system, it reaches its target sites. Adrenaline and noradrenaline are released when the body is a state of stress induced by stimuli. The two hormones are regulated by the enzyme monoamine oxidase that breaks down these hormones (Melmed et al., 2015). 2. According to Melmed (2015) the clinical assays performed to analyze adrenal function are: Tests Assessment Serum and urine cortisol The amount of cortisol in the urine is measured at specific time intervals throughout the day. Cortisol level in the blood is also measured. Urine steroids The amount of steroid hormone in urine is measured at midnight. Serum ACTH ACTH level in blood is measured as it regulates cortisol level. ACTH stimulation This test determines how the adrenal gland responds to ACTH. Metyrapone stimulation It determines the dependency or independency on ACTH in Cushings disease. Dexamethasone suppression It is used to determine adrenal function in response to dexamethasone stimulation. Task 2 1. Triiodothyronine (T3) and Thyroid hormones thyroxine (T4) acts on all cells of the body. They regulate the basal metabolism and heat production by the body (Braverman Cooper, 2012). Target of thyroid hormones Response Cardiovascular system Heart functions normally Nervous system Normal development and function of the nervous system. Muscular system Muscular function and development are normal Carbohydrate-protein-lipid metabolism Promotes synthesis of cholesterol and proteins. Mobilizes fat and glucose catabolism. Skeletal system Usual maturation and growth of skeleton BMR and temperature regulation Increases impact of the sympathetic nervous system and regular use of oxygen. Reproductive system Lactation and normal reproductive ability in female GI system Enhances digestive fluid secretion and normal GI tone and motility Integumentary system Normal secretion activity and hydration of skin 2. Normal Primary hypothyroidism Secondary hypothyroidism Hyperthyroidism T4 (total) 4.5-11.5 ug/dL Low Low High TSH 0.3-5.0 U/dL High low Low T3 (total) 75-200 ng/dL Normal Normal High 3. According to Braverman Cooper (2012).Normal ranges of thyroid hormones are: T3: 75-200 ng/dL T4: 4.5-11.5 ug/dL TSH: 0.3-5.0 U/dL Thyroglobulin: 3-40 ng/ml 4. The assessment of thyroid function and dysfunction is done by analyzing the amount of thyroid hormones present in the blood. The amount of thyroid hormones- T3, T4, TSH and thyroglobulin in the blood is measured. The principles of the tests are that the values of the thyroid hormones present in the blood should be in the normal range. If the amounts of these hormones change, it can be inferred that the thyroid is not functioning normally (Braverman Cooper, 2012). 5. Hypothyroidism Hyperthyroidism Symptoms: Fatigue, unexplained weight gain and trouble in losing weight, dry hair and hair loss, depression, dry skin, goiter (swelling of the thyroid gland), muscle cramps, slow heart rate and irregular period, brittle nails, constipation, sensitivity to cold and carpal tunnel syndrome. Symptoms: Unexplained weight loss, racing heartbeat, feeling wired or anxious, feeling hot, frequently, shakiness, sweating spells, red itchy skin, fine hair and hair loss, and more frequent bowel movements than usual References: Braverman, L. E., Cooper, D. (2012).Werner Ingbar's the thyroid: a fundamental and clinical text. Lippincott Williams Wilkins. Melmed, S., Polonsky, K. S., Larsen, P. R., Kronenberg, H. M. (2015).Williams textbook of endocrinology. Elsevier Health Sciences.