Question

What does the Thyroid Gland Secrete?

a) Cortisol
b) Thyroxine and triiodothyronine
c) Insulin
d) Estrogen and progesterone

Answer 1

The thyroid gland secretes thyroxine (T4) and triiodothyronine (T3), which regulate the body's metabolic processes and influence various physiological functions.

Step-by-step explanation:

The thyroid gland secretes two primary hormones, which are thyroxine (T4) and triiodothyronine (T3). These hormones are crucial for regulating the body's metabolic rate, as well as influencing heart and digestive function, muscle control, brain development, and bone maintenance. The synthesis of thyroid hormones involves the amino acid tyrosine and the element iodine. The thyroid gland uses an active transport mechanism to take up iodide, which is then oxidized and incorporated into tyrosine to form T3 and T4. These hormones then exert their effects on various tissues throughout the body.

Answer 2

Thyroid Gland Secrete b) Thyroxine and triiodothyronine

Step-by-step explanation:

The thyroid gland primarily secretes two hormones, (B)thyroxine (T₄) and triiodothyronine (T₃), represented by option b. These hormones play a crucial role in regulating the body's metabolism, energy production, and overall growth and development. Thyroxine (T₄) is the major hormone produced by the thyroid gland and is converted into the more active triiodothyronine (T₃) in various tissues throughout the body.

Thyroid hormones are synthesized from the amino acid tyrosine and iodine. The thyroid gland absorbs iodine from the bloodstream and incorporates it into tyrosine to produce T₄ and T₃. The numbers in the hormone names, T₄ and T₃, indicate the number of iodine atoms in each molecule. For instance, thyroxine (T₄) contains four iodine atoms, while triiodothyronine (T₃) contains three. The release of these hormones is tightly regulated by the thyroid-stimulating hormone (TSH) produced by the pituitary gland. TSH stimulates the thyroid gland to release T₄ and T₃, maintaining a delicate balance in the body's metabolic activities.

In summary, the thyroid gland's secretion of thyroxine and triiodothyronine is crucial for maintaining homeostasis in the body, influencing energy production, metabolism, and overall growth and development. The regulation of thyroid hormone secretion is a complex process involving feedback mechanisms and hormonal control, highlighting the intricate interplay within the endocrine system.