Found at 2nd through 4th cartilages of the trachea v Small gland with four parathyroid glands attached to the posterior surface v Follicles are the structural unit of the gland v Follicle consists of a wall of simple cuboidal epithelium cells inclosing a space containing a jelly like substance called colloid if the colloid distends the follicles, the epithelial cells can become flattened almost like simple squamous. Colloid combines with iodine to form thyroid hormones -regulate body metabolism✓Found at 2 nd through 4 th cartilages of the trachea ✓Small gland with four parathyroid glands attached to the posterior surface. ✓Follicles are the structural unit of the gland. ✓Follicle consists of a wall of simple cuboidal epithelium cells inclosing a space containing a jelly￾like substance called colloid. If the colloid distends the follicles, the epithelial cells can become flattened almost like simple squamous. Colloid combines with iodine to form thyroid hormones – regulate body metabolism