Wednesday 1 May 2013
Definition: Goblet cells are glandular simple columnar epithelial cells whose function is to secrete mucin, which dissolves in water to form mucus. They use both apocrine and merocrine methods for secretion.
The term goblet refers to these cells’ goblet-like shape. The apical portion is shaped like a cup, as it is distended by abundant mucinogen granules; its basal portion is shaped like a stem, as it is narrow for lack of these granules.
There are other cells that secrete mucus (as in the foveolar cells of the stomach), but they are not usually called "goblet cells" because they do not have this distinctive shape.
The majority of the cell’s cytoplasm is occupied by mucinogen granules, except at the bottom. Rough endoplasmic reticulum, mitochondria, the nucleus, and other organelles are concentrated in the basal portion. The apical plasma membrane projects microvilli to increase surface area for secretion. Recent study suggests that glycoprotein is located inside goblet cells. It is an organ-specific antigen in the gut.
The goblet cells are found scattered among the epithelial lining of organs, such as the intestinal and respiratory tracts.
Goblet cells are found inside the trachea, bronchus, and larger bronchioles in respiratory tract, small intestines, the colon, and conjunctiva in the upper eyelid.(Goblet cells are the chief source of tear mucus.
These occur throughout the conjunctiva, especially the plica semilunaris.
These are most dense in nasal conjunctiva, least dense in upper temporal fornix and absent in palpebral mucocutaneous junction and limbus.)
They may be an indication of metaplasia, such as in Barrett’s esophagus.