Define T3 and T4 in thyroid gland and how it produced?

Thyroid gland is the largest endocrine gland which produced thyroid hormone and calcitonin. Thyroid gland consist of spherical hollow sacs called thyroid follicles. Work of thyroid follicles is the accumulation of iodide from the blood and secret it into colloids. Within the colloids, iodide is oxidized into iodine and attached to tyrosine of thyroglobulin protein. If one iodine is attached to tyrosine residue then monoiodotyrosine(MIT) will produced and two iodine attached to tyrosine then Diiodotyrosine (DIT) produced. Using enzyme within the colloid it modifies and couple together and form T3 and T4.br /When two DIT modify and coupled together then T4 means Tetraiodothyronine produced.br /When MIT and DIT combined then T3 means triiodothyronine will produced.