👉 In anatomy, a "metacone" is a small organ or sac that forms at the base of the thyroid gland. It contains some type of endocrine cells and may be involved in regulating thyroid hormone production and metabolism. Metacones are also known as the paracrine thyroid glands. This term refers to the fact that they can produce hormones like thyroxine (T4) and triiodothyronine (T3), which play a role in regulating thyroid function by affecting various processes