|Section of mucus membrane of human stomach, near the cardiac orifice. X 45.
c. Cardiac glands.
d. Their ducts.
cr. Gland similar to the intestinal glands, with goblet cells.
mm. Mucous membrane.
m. Muscularis mucosae.
m’. Muscular tissue within the mucous membrane.
|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.
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.
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.)
In mucicarmine stains, deep red mucin found within goblet cell bodies.
The nuclei of goblet cells tend to be displaced toward the basal end of the cell body, leading to intense basophilic staining.
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.
Basal secretion 
Stimulated secretion 
Other stimuli include viruses, bacteria, etc.
Role in Oral Tolerance 
Oral tolerance is the proccess 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.
See also 
- Goblet cell carcinoid - a tumor that has a component that is similar to goblet cells
- "goblet cell" at Dorland's Medical Dictionary
- BU Histology Learning System: 11303loa - Digestive System: Alimentary Canal: fundic stomach, gastric glands, lumen"
- McDole et al. (2012). "Goblet cells deliver luminal antigen to CD103+ dendritic cells in the small intestine". Nature 483: 345–349. doi:10.1038/nature10863. PMID 22422267.
Additional images 
Goblet cell in ileum
- Histology at KUMC epithel-epith08 "Slide 8: Trachea"
- Goblet+cell at eMedicine Dictionary
- Goblet Cells at cvmbs.colostate.edu
- Diagram at uwlax.edu
- Bioweb at UWLAX Zoolab