Final answer:
Anti-receptor antibodies can have different consequences on thyroxin and TSH levels depending on whether they block or stimulate the receptors on the pituitary or thyroid gland. Blocking the receptors can result in decreased hormone production, while stimulating the receptors can lead to overproduction of hormones.
Step-by-step explanation:
In the case when anti-receptor antibodies block the thyroxin receptors on the pituitary, the feedback loop that controls the production of thyroid hormones would be disrupted. This would result in a decrease in thyroxin levels since the pituitary is unable to receive the signal to produce and release thyroid-stimulating hormone (TSH), which stimulates the thyroid gland to secrete thyroxin.
On the other hand, if the anti-receptor antibodies stimulate the thyroxin receptors on the pituitary, the feedback loop would also be disrupted. This would lead to an excessive production and release of TSH, which in turn would cause an overproduction of thyroxin by the thyroid gland.
If the anti-receptor antibodies block the TSH receptors on the thyroid, this would prevent TSH from binding and stimulating the thyroid gland. As a result, there would be a decrease in the production and release of thyroid hormones, including thyroxin.
Lastly, if the anti-receptor antibodies stimulate the TSH receptors on the thyroid, the feedback loop would be disrupted. This would cause an increase in TSH levels, leading to an overproduction of thyroid hormones.