Definition

1. Noun:
   • A hormone produced by the thyroid gland: Tetraiodothyronine is the primary hormone secreted by the thyroid gland. Its main function is to regulate the body's metabolic rate by controlling the speed of cellular processes.
   • A chemical compound: It is an iodine-containing amino acid derivative. Chemically, it is known as thyroxine and is often abbreviated as T4.

Usage Examples

• Noun:
  • The doctor ordered a test to measure the level of tetraiodothyronine in her blood.
  • A deficiency in tetraiodothyronine can lead to symptoms of hypothyroidism, such as fatigue and weight gain.
  • Tetraiodothyronine is critical for normal growth and development.

Advanced Usage

• Medical Context: In clinical settings, "tetraiodothyronine" is often referred to by its common name, thyroxine, or its abbreviation, T4. It is typically measured as part of a thyroid function panel to diagnose thyroid disorders.
  • The lab report showed her free T4 (tetraiodothyronine) levels were within the normal range.

Variants and Related Words

• Thyroxine (n): The common name for tetraiodothyronine. This term is used more frequently in general and medical contexts.
  • The patient was prescribed synthetic thyroxine.
• T4 (n): The standard abbreviation for thyroxine/tetraiodothyronine.
  • The T4 test is a standard part of a thyroid check-up.
• Triiodothyronine (n): Often abbreviated as T3, this is another, more metabolically active hormone produced by the thyroid gland, closely related to T4.
  • The body converts some T4 into triiodothyronine (T3) in the tissues.

Synonyms

• Thyroxine: The direct and most common synonym.
• T4: The abbreviated synonym used primarily in medical contexts.

Related Terms and Concepts

• Thyroid gland: The endocrine gland that produces tetraiodothyronine.
• Metabolism: The set of life-sustaining chemical reactions whose rate is regulated by this hormone.
• Hypothyroidism: A condition characterized by underproduction of thyroid hormones like tetraiodothyronine.
• Hyperthyroidism: A condition characterized by overproduction of thyroid hormones like tetraiodothyronine.

Noun

1. hormone produced by the thyroid glands to regulate metabolism by controlling the rate of oxidation in cells
   • thyroxine is 65% iodine