Generally believed that, ETG, including thyroid and parathyroid vagus.
Currently, ETG, the definition and name of the outstanding unity. Generally believed that, ETG, including thyroid and parathyroid vagus. Thyroid in its development process down to the neck did not arise in the normal position when the other parts of the formation of the so-called ETG. When the anterior absence of the normal position when the thyroid gland, ETG is called vagus thyroid, cervical normal position when there is gland, ETG is known as the parathyroid gland, also known as extra on thyroid.