Video Transcript
Which of the following is a hormone
secreted by the thyroid gland? (A) Thyroid-stimulating hormone,
(B) thymus, (C) parathyroid, or (D) thyroxine.
The thyroid gland is located at the
base of the neck, just below the larynx or voice box, and is part of the human
endocrine system. The thyroid gland secretes hormones
into the blood that control various bodily functions, such as metabolism, growth,
and development. The question asks us to identify
which of the options is a hormone secreted by the thyroid gland. So let’s take a look through the
choices to figure out the answer.
Option (A), thyroid-stimulating
hormone is a hormone secreted by another gland of the endocrine system called the
pituitary gland. The pituitary gland is located in
the brain and is often called the master gland because it controls the functions of
several of the other glands in the endocrine system. As the name suggests,
thyroid-stimulating hormone, or TSH, works to trigger the thyroid gland to secrete
thyroid hormones. TSH is not actually produced by the
thyroid gland though, so we can eliminate this choice.
Next, option (B) is the thymus,
which is not actually a hormone at all. The thymus is another endocrine
gland, located in the upper chest between the lungs and beneath the breast bone. This gland releases hormones that
play an important role in the immune system. And as we know that it is not a
hormone, let alone one released from the thyroid gland, we can eliminate this answer
choice too.
Option (C), parathyroid, is another
gland that belongs to the endocrine system. In fact, there are four parathyroid
glands, located on the back surface of the thyroid gland, that produce their own
hormone, parathyroid hormone. This option can be eliminated too
as it is not a hormone secreted from the thyroid gland.
Finally, option (D), thyroxine, is
one of the thyroid hormones and plays a crucial role in several important life
processes. Thyroxine influences growth and
metabolism, promotes brain development and function, and even helps maintain healthy
skin and hair. As thyroxine is produced by the
thyroid gland, this is the answer we are looking for. The correct answer is therefore
(D), thyroxine.
