What action does thyroxine have in the body?
Thyroxine is the main hormone secreted into the bloodstream by the thyroid gland. It plays vital roles in digestion, heart and muscle function, brain development and maintenance of bones.
What is the action of thyroid?
What does the thyroid gland do? The thyroid gland produces hormones that regulate the body’s metabolic rate controlling heart, muscle and digestive function, brain development and bone maintenance. Its correct functioning depends on a good supply of iodine from the diet.
What is the action of T3 and T4?
The main activity of the thyroid hormones T3 and T4 is to boost the basal metabolic rates of proteins, fats, and carbohydrates as well as vitamins.
What is the mechanism of action of thyroid gland?
The thyroid hormone receptors belong to a nuclear receptor superfamily that also includes receptors for other small lipophilic hormones. Thyroid hormone receptors function by binding to specific thyroid hormone-responsive sequences in promoters of target genes and by regulating transcription.
What is thyroxine target organ?
Once in the bloodstream, thyroxine travels to the organs, like the liver and kidneys, where it is converted to its active form of triiodothyronine. Thyroxine plays a crucial role in heart and digestive function, metabolism, brain development, bone health, and muscle control.
Why is thyroxine used?
Levothyroxine is used to treat an underactive thyroid (hypothyroidism). It replaces or provides more thyroid hormone, which is normally produced by the thyroid gland. Low thyroid hormone levels can occur naturally or when the thyroid gland is injured by radiation/medications or removed by surgery.
What is T4 responsible for?
Thyroxine (T4) is responsible for your metabolism, mood, and body temperature, among other things. T3, too, is made in the thyroid gland, and it can also be made in other tissues within the body by converting T4 (in a process called deiodination) into T3.
What are the target cells of thyroxine?
| Endocrine gland/ source of hormone | Hormone | Target organ or tissue |
|---|---|---|
| Thyroid | Thyroxine (T4) Triiodothyronine (T3) | Most tissues |
| Calcitonin | Bone | |
| Parathyroids | PTH (parathyroid hormone) | Bone, kidneys, intestine |
| Thymus (regresses in adulthood) | Thymopoetin | T-lymphocyte cells in blood |
What are the roles of thyroxine and adrenaline?
Thyroxine is produced from the thyroid gland, which stimulates the basal metabolic rate. It controls the speed at which oxygen and food products react to release energy for the body to use.
How does thyroxine affect target cells?
In the target cells, enzymes remove one of thyroxine’s four iodine atoms converting the hormone into the highly active triiodothyronine.
What effects does thyroxine have on the body?
Thyroxine is one of the main hormones secreted from the thyroid follicular cells. Within the body, thyroxine affects the body’s metabolism and has an effect on protein synthesis. It is also important for human growth and development, as it regulates bone growth and aids in the maturation of neurons.
What does thyroxine help regulate?
Thyroxine plays a crucial role in heart and digestive function, metabolism, brain development, bone health, and muscle control . It affects almost all of the body’s systems, which means proper thyroxine levels are vital for health.
What is the action of thyroxine in the cells?
Thyroxine’s principal function is to stimulate the consumption of oxygen and thus the metabolism of all cells and tissues in the body. Thyroxine is formed by the molecular addition of iodine to the amino acid tyrosine while the latter is bound to the protein thyroglobulin.
How does thyroxine stimulate growth?
Thyroxine stimulates oxidative metabolism in cells and increases the oxygen consumption and heat production of most body tissues, with the notable exception of the brain. Thyroxine is also necessary for normal growth, likely by promoting the effects of growth hormone on protein synthesis.