What is T3 and T4 responsible for?
What is T3 and T4 responsible for?
What is T3 and T4 responsible for?
It is located in front of the neck and is responsible for the production of thyroid hormones. The thyroid gland releases triiodothyronine (T3) and thyroxine (T4). These hormones play an important role in regulation of your weight, energy levels, internal temperature, skin, hair, nail growth, and more.
What regulates T3 T4?
T3 and T4 production is regulated by thyroid stimulating hormone (TSH) secreted by the pituitary gland, which is in turn regulated by thyrotropin-releasing hormone (TRH) secreted by the hypothalamus.
What is the difference between T3 and T4?
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 is the mechanism of action of T3 and T4?
The influences that thyroid hormones have on these diverse functions are primarily mediated through binding of T3 and T4 to specific nuclear receptor sites. The nuclear action of T3 results in organ-specific increases and decreases of specific mRNAs, leading to alteration in the level of the corresponding proteins.
How does T3 and T4 affect metabolism?
Because the thyroid hormones T3 and T4 control cellular metabolism throughout the body, when there is not enough of them for any reason, this metabolic function slows and becomes impaired.
What are the target cells of T3 and T4?
| 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 enzyme converts T4 to T3?
T4 is converted into T3, the active form of thyroid hormone, by two enzymes called deiodinases. People with hypothyroidism are treated with a synthetic T4 hormone, which the enzymes convert to T3.
What is the target organ of estrogen?
Estrogens have multiple effects on the growth and development of cells in their target tissues, including the uterus, ovary, breast, bone marrow and brain. The hormone regulates the transcription of diverse genes in these tissues via the estrogen receptor, a nuclear transcription factor.
How does T3 and T4 affect the body?
T3 and T4 travel in your bloodstream to reach almost every cell in the body. The hormones regulate the speed with which the cells/metabolism work. For example, T3 and T4 regulate your heart rate and how fast your intestines process food.