Goblet cells are found scattered among the epithelial lining of organs, such as the intestinal and respiratory tracts. They are found inside the trachea, bronchi, and larger bronchioles in the respiratory tract, small intestines, the large intestine, and conjunctiva in the upper eyelid. In the conjunctiva goblet cells are a source of mucin in tears and they also secrete different types of mucins onto the ocular surface. In the lacrimal glands, mucus is synthesized by acinar cells instead.