glandular epithelial cells in vertebrate animals and man that secrete mucus. Goblet cells are distributed individually in the mucous membranes of the intestine, air passages, efferent ducts of the pancreas and parotid glands, and the conjunctiva of the eyes. Goblet cells are formed from ordinary epithelial cells. The upper part of goblet cells, which is covered with microvilli, accumulates granules of secretion (mucinogen) that turn into a mass of mucus (mucin) when they absorb water. Goblet cells acquire the shape of a goblet (hence the name) when their apex swells and their base narrows. The upper part of the cells is then destroyed (apocrine secretion) and mucus is released into the lumen of the organ. The walls of the goblet cells collapse, become prismatic, and begin again to accumulate secretion.