Final answer:
It is false that the stored thyroid hormone in the thyroid gland will only last for a couple of weeks; it can actually last from a few weeks to several months based on the hormone's storage form and the body's mechanism for conserving and regulating hormone release.
Step-by-step explanation:
False. The thyroid gland has a significant reserve of thyroid hormone that can last a few weeks to several months.
The thyroid gland stores hormones in the form of thyroglobulin, which is a glycoprotein containing thyroid hormones T3 and T4. This storage form allows the gland to maintain a supply that can last beyond just a couple of weeks. It is common for individuals with a thyroid disorder to experience a period of weeks or even months before hormone levels normalize and symptoms resolve after starting or stopping thyroid medication. The release of T3 and T4 from the gland is regulated by thyroid-stimulating hormone (TSH) from the anterior pituitary.
When blood levels of free hormones decrease, the bound forms are released to be used by the body. This mechanism maintains a reserve of hormone, suggesting a storage capacity that could cover several weeks to months, depending on the body's demand for thyroid hormones. The duration of the stored hormones' effectiveness reflects the body's ability to conserve and regulate the release of T3 and T4 according to physiological needs.