<prompt> Active thyroid follicles are lined by which type of epithelium?ColumnarCuboidalSquamousPseudostratified squamous  <response>: The thyroid follicle is the structural and functional unit of the thyroid gland. The thyroid gland stores its secretory substances in the lumina of follicles. These cyst-like structures, ranging from 0.2 to 0.9 mm in diameter, are composed of a simple cuboidal epithelium, composed of follicular cells surrounding a central colloid-filled lumen and contacting the colloid as well as parafollicular cells clear cells; C cells that are located at the periphery of the follicle and do not contact the colloid.Ref: Textbook of Histology, 4thedition; Chapter 13; Endocrine system; Page no: 355 