Final answer:
Thyroid disease does not decrease the pulse rate. In fact, it can increase the pulse rate due to the effects of thyroid hormones on cardiac rate and contractility.
Step-by-step explanation:
False. Thyroid disease does not decrease the pulse rate. In fact, thyroid hormones have been shown to increase cardiac rate and contractility, which can lead to an increased pulse rate. Excessive levels of thyroid hormone, known as thyroxin, may even trigger tachycardia, a condition characterized by a rapid heart rate.
It's false to universally claim that thyroid disease decreases pulse rate; this is only true for hypothyroidism. In contrast, hyperthyroidism, such as that caused by Graves' disease, results in increased heart rate. The action of thyroid hormones like T3 and T4 occurs inside the nucleus, not on the plasma membrane of target cells.
The statement that thyroid disease decreases the pulse rate is not entirely accurate without context. Hyperthyroidism is a condition characterized by an overactive thyroid gland, which increases the production of thyroid hormones thyroxin (T4) and triiodothyronine (T3). Higher levels of these hormones increase cardiac rate and contractility, often leading to tachycardia (increased heart rate). On the other hand, hypothyroidism involves an underactive thyroid gland that results in lower production of thyroid hormones. This can lead to bradycardia (decreased heart rate), along with symptoms like weight gain, cold sensitivity, and fatigue, as seen in Patient A. Therefore, the statement would only be true in the context of hypothyroidism.
Graves' disease is a condition that causes an excess of thyroid hormone production. This contradicts the initial statement, as it usually results in a higher pulse rate. Comparatively, T3 and T4 do not bind to receptors on the plasma membrane of target cells; they enter cells and act within the nucleus, altering gene activity.