thyroxine

Examples of thyroxine in the following topics:

• Development of the Endocrine System

  • It is involved in the production of the hormones T3 (triiodothyronine) and T4 (thyroxine).
  • The normal thyroid gland may store several weeks supply of thyroxine in this bound form.
  • Thyroxine is also necessary for normal growth.
  • If there is an insufficient amount of thyroxine, a condition referred to as hypothyroidism results.
  • Sometimes, the thyroid gland produces too much thyroxine, a condition known as hyperthyroidism.

• Control of Thyroid Hormone Release

  • The production of thyroxine and triiodothyronine is regulated by thyroid-stimulating hormone (TSH) that is released from the anterior pituitary.
  • The production of thyroxine (T4) and triiodothyronine (T3) is primarily regulated by thyroid-stimulating hormone (TSH) that is released from the anterior pituitary gland.

• Control of Hormone Secretion

  • A key example of a negative feedback system is the regulation of the thyroid hormone thyroxine, which regulates numerous key metabolic processes.
  • The thyroid-stimulating hormone then stimulates the release of thyroxine from the thyroid gland.
  • When the blood concentration of thyroxine rises above the ideal value as detected by sensory neurons, the hypothalamus is signaled to stop thyroid-releasing hormone production, which eventually lowers the levels of thyroxine in the blood.

• Action of Thyroid Hormones

  • The primary function of the thyroid is to produce the hormones triiodothyronine (T3), thyroxine (T4), and calcitonin.
  • Triiodothyronine (T3) and thyroxine (T4) are enzymes produced by the thyroid gland.
  • In the blood, T4 and T3 are partially bound to thyroxine-binding globulin (TBG), transthyretin, and albumin.

• Formation, Storage, and Release of Thyroid Hormones

  • The thyroid hormones thyroxine (T4) and triiodothyronine (T3) are produced from thyroid follicular cells within the thyroid gland, a process regulated by the thyroid-stimulating hormone secreted by the anterior pituitary gland.

• Thyroid Gland

  • The thyroid gland produces the hormones T3 (triiodothyronine) and T4 (thyroxine).

• Overview of the Thyroid Gland

  • It participates in these processes by producing thyroid hormones, the principal ones being triiodothyronine (T3) and thyroxine (sometimes referred to as tetraiodothyronine (T4)).

• Pituitary Gland Disorders

  • Once the effector glands produce sufficient hormones (thyroxine, cortisol, estradiol or testosterone and IGF-1), both the hypothalamus and the pituitary cells sense their abundance and reduce their secretion of stimulating hormones.
  • Thyroid-stimulating hormone (TSH) deficiency leads to hypothyroidism (lack of production of thyroxine (T4) and triiodothyronine (T3) in the thyroid).

• Halogen Compounds

  • Iodine is needed in trace amounts for the production of thyroid hormones, such as thyroxine.

• Lipid-Derived, Amino Acid-Derived, and Peptide Hormones

  • Examples of amino acid-derived hormones include epinephrine and norepinephrine, which are synthesized in the medulla of the adrenal glands, and thyroxine, which is produced by the thyroid gland.