Which hormone deficiency causes the formation of goiters?

The formation of goiters is primarily associated with a deficiency in thyroxine, a hormone produced by the thyroid gland. Thyroxine, also known as T4, plays a crucial role in regulating metabolism and is essential for normal growth and development. When there is not enough thyroxine in the body, the thyroid gland may enlarge in an attempt to produce more of this hormone, leading to the development of a goiter.

This enlargement is often a response to insufficient dietary iodine, which is necessary for the synthesis of thyroxine. When iodine is lacking, even if the thyroid gland is functioning, it cannot produce enough thyroxine, prompting its enlargement. Thus, a deficiency of thyroxine directly results in the stimulation of the thyroid gland, leading to the formation of a goiter.

In contrast, other hormones and compounds mentioned do not directly cause goiter formation. Insulin is involved in glucose metabolism, adrenaline affects the body's fight-or-flight response, and tyrosine is an amino acid that serves as a precursor for the synthesis of thyroid hormones but is not a hormone itself. Therefore, the correct answer highlights the significance of thyroxine deficiency in the context of goiter formation.