Thyroid Histology Lab

3. Please answer the following questions regarding the thyroid and parathyroid glands. a. The structural unit of the thyroid is thyroid follicle . b. Thyroid follicles consist of a layer of simple cuboidal epithelium enclosing a cavity filled with an iodine rich colloid suspension containing a glycoprotein called thyroglobulin which contains the thyroid (T 3 and T 4 ) hormones. c. The Interfollicular spaces are filled with reticular connective tissue, adipose tissue, blood vessels, and parafollicular cells which produce calcitonin hormone. d. The parathyroid glands are normally located on the posterior surface of the thyroid gland. e. The parathyroid glands produce parathyroid hormone and monitor the blood calcium ion level. 4. Please answer the following questions regarding thyroid hormone synthesis and secretion. a. The amino acid tyrosine is the precursor for the synthesis of thyroid hormones. b. The iodine ion is incorporated into T3 and T4 synthesis; it is transported from the blood into the thyroid gland by sodium-iodine symporter transport. c. T 3 is the potent form of thyroid hormones. d. Most of the thyroid hormones circulate in the blood are bound to a protein called TBG (thyroxine-binding globulin) . e. The TRH (thyrotropin-releasing) hormone produced by the hypothalamus -> stimulates the secretion of the TSH (thyroid-stimulating) hormone by the pituitary gland -> stimulates the secretion of the T 4 and T 3 by the thyroid gland. T 3 and T 4 exert negative feedback on the hypothalamus and pituitary gland . 5. Please answer the following questions regarding hypothyroidism versus hyperthyroidism. a. In Graves’ disease, which of the following chemicals overstimulates the thyroid gland? o TRH o TSH o T 3 and T 4 o TSI b. A patient is admitted to the ER with complaints of palpations. In addition, the patient presents with protruding eyeballs. Which of the following is the likely cause of the patient's signs and symptoms? o Thyroiditis o Deficiency of iodine consumption o Grave's Disease o Hypothyroidism c. A patient has an extremely high T3 and T4 blood level due to a proliferative tumor of the thyroid gland. This abnormality is likely to cause which of the following fluctuations due to negative feedback? o Increased TRH secretion o Increased TSH secretion o Increased TRH and TSH secretion o Decreased TRH and TSH secretion d. A patient has an extremely low T3 and T4 blood level due to a destructive tumor of the thyroid gland. This abnormality is likely to cause which of the following fluctuations due to negative feedback inhibition?