Schematic illustration of a goblet cell in close up, illustrating different internal structures of the cell.
Transverse section of a villus, from the human intestine. X 350.
a. Basement membrane, here somewhat shrunken away from the epithelium.
c. Columnar epithelium.
d. Its striated border.
e. Goblet cells.
f. Leucocytes in epithelium.
f’. Leucocytes below epithelium.
g. Blood vessels.
h. Muscle cells cut across.
A goblet cell is a glandular simple columnar epithelial cell whose function is to secrete gel forming mucins, which are the major component of mucus. The goblet cells use both apocrine and merocrine methods for secretion.
The majority of the cell's cytoplasm is occupied by mucinogen granules, except at the bottom, where rough endoplasmic reticulum, mitochondria, the nucleus, and other organelles are concentrated. The apical plasma membrane projects microvilli to increase surface area for secretion.
They are found scattered among the epithelial lining of organs, such as the intestinal and respiratory tracts. They 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.)
The nuclei of goblet cells tend to be displaced toward the basal end of the cell body, leading to intense basophilic staining.
In mucicarmine stains, deep red mucin found within goblet cell bodies. Goblet cells can be seen in the examples below as the larger, more pale cells.
Types of secretion
- Basal secretions. This is the normal base level secretion of mucus, which is accomplished by cytoskeletal movement of secretory granules.
- Stimulated secretion. Secretion may be stimulated by dust, smoke, etc. Other stimuli include viruses, bacteria, etc.
Role in oral tolerance
Oral tolerance is the process by which the immune system is prevented from responding to antigen derived from food products, as peptides from food may pass into the bloodstream via the gut, which would in theory lead to an immune response. A recent paper published in Nature, has shed some light on the process and implicated goblet cells as having a role in the process. It was known that CD103 expressing dendritic cells of the lamina propria had a role to play in the induction of oral tolerance (potentially by inducing the differentiation of regulatory T cells), and this paper suggests that the goblet cells act to preferentially deliver antigen to these CD103+ dendritic cells.
- Goblet cell carcinoid - a tumor that has a component that is similar to goblet cells
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.
- "goblet cell" at Dorland's Medical Dictionary
- McDole et al. (2012). "Goblet cells deliver luminal antigen to CD103+ dendritic cells in the small intestine". Nature 483 (7389): 345–349. doi:10.1038/nature10863. PMC 3313460. PMID 22422267.
- Histology image:11303loa from Vaughan, Deborah (2002). A Learning System in Histology: CD-ROM and Guide. Oxford University Press. ISBN 978-0195151732. - Digestive System: Alimentary Canal: fundic stomach, gastric glands, lumen"