Final answer:
The notion that all thyroid disorders require lifelong medication is false, as treatment depends on the specific condition and its underlying cause. Symptom visibility can also be misleading since many thyroid conditions present with mild or nonspecific symptoms. Furthermore, T3 and T4 hormones bind within cells, and excessive thyroid hormone production is caused by Graves' disease.
Step-by-step explanation:
The belief that once diagnosed with a thyroid disorder, a person is bound to take medication for life is a myth. Thyroid conditions vary; some require lifelong treatment, while others may only need temporary medication. For instance, hypothyroidism often necessitates ongoing thyroid hormone supplementation, as the body lacks sufficient production of thyroxine (T4). However, treatment duration can depend on the condition's cause, with some cases potentially allowing for a reduction or discontinuation of medication over time.
Another common misconception is that thyroid disorders are always accompanied by clear symptoms that cannot be overlooked. In reality, many individuals with thyroid issues, such as variations in thyroid-stimulating hormone (TSH) levels or thyroglobulin, experience subtle or nonspecific symptoms. As such, the condition can be easily missed without proper blood tests measuring thyroid hormone levels.
Lastly, with regard to thyroid hormones, T3 and T4, rather than attaching to receptors on the plasma membrane, they actually enter the target cells and bind to receptors within the cell. As for the disease that causes excessive production of thyroid hormones, the answer is B. Graves' disease, not A. Hashimoto's thyroiditis, C. Goiter, or D. Iodine deficiency.