What type of gland is the thyroid gland classified as?

The thyroid gland is classified as an endocrine gland because it secretes hormones directly into the bloodstream, which then travel to various tissues in the body to regulate numerous physiological processes. This includes the regulation of metabolism, growth, and development, as well as maintaining body temperature.

Endocrine glands, like the thyroid, are distinguished by their lack of ducts; they release their secretions (hormones) internally, in contrast to exocrine glands, which release their substances through ducts to the surface of organs or into cavities. Additionally, while mixed glands can possess both exocrine and endocrine functions, the thyroid is solely involved in hormone secretion. The term secretory describes glands broadly but does not specify the type of gland as cohesively as "endocrine" does in the context of hormone production and release.