Graphic (image) UT Southwestern Medical Center Share Print E-Mail Caption The pituitary gland in the brain produces a hormone known as TSH, which enters the bloodstream and stimulates the thyroid gland in the neck to make thyroid hormone T4 (thyroxine). The thyroid hormone is essential for regulating metabolism and brain development, maturation, and function. Source: National Institutes of Health Credit UT Southwestern Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.