The human body is millions of cells of various shapes, types and sizes. They are so small that they can only be examined and studied under a microscope. In fact, cells are microscopic bricks from which tissues, organ systems and the whole body are built. Despite the difference in forms, all cells are characterized by a general structure scheme. They consist of an outer membrane, a central nucleus, and a semi-fluid cytoplasm. We can talk about different types of cells for a long time, but in this article we will consider only one kind, called goblet cells. We will try to understand what they are, where they are localized and how they function.
Name Options
Such cells are known by several names. Often used the phrase "enterocyte goblet", "goblet exocrinocide" and "goblet granulocyte." In Latin, a goblet cell is called enterocytus caliciformis. The term "goblet cell" is sometimes used, which also refers to a goblet cell. All these terms are equivalent to each other and are used as synonyms.
The name reflected the unusual shape of the cells. They look like a tall narrow glass, slightly expanding up.
Cells of this type belong to the epithelium of the mucous membranes and are involved in the production of mucus. They are present in the body of both humans and animals.
Localization. Intestines
The goblet cell is part of the epithelium of several human organs. One of the places of localization is the intestines. The intestinal epithelium has a rather complex structure. It combines several types of enterocytes, including limbic, goblet, acidophilic, borderless, endocrine, poorly differentiated and others. All of them are unicellular glands with different functions. For example, limbic epithelial cells are involved in parietal digestion and absorption. Goblet are responsible for the production of mucus (more on this below). Endocrine cells produce hormones in the intestinal tract, acidophilic Pannet cells produce several digestive enzymes. The function of poorly differentiated cells is the regeneration of the epithelium.
Goblet cells of the intestine are located on the intestinal villi. They are inserted one by one between the limbic cells. Goblet cells are not found on the apical parts of the villi and in the tubular depressions of the mucous membrane, called the liberkune glands or intestinal crypts. Although there are rare exceptions.
In the small intestine, there are more cells of this species. 9.5% of enterocytes are goblet cells of the epithelium. Moreover, their number increases in the distal direction of the intestine. They are evenly distributed over the upper part of the crypts and the base of the villi; on the villi themselves they are much smaller.
Airways
Another place for the localization of goblet exocrinocytes is the respiratory tract. Here, almost 30% of the epithelium consists of these cells. Cells are also located singly. They have vacuoles filled with mucous secretion. Vacuoles occupy the expanded apical part. The narrowed part of the cell contains a Golgi complex and many mitochondria. The goblet cell of the respiratory tract is equipped with microvilli, which become more noticeable after mucus secretion.
The secretion of mucus is cyclical in nature, which depends on external factors, that is, on temperature and humidity.
Goblet cells of the conjunctiva
The next place for the localization of goblet cells is the conjunctiva of the eye. There are a lot of them in the conjunctival mucosa. The secret secreted by these cells differs from the mucus secreted by the epithelium in other organs. The goblet cells of the conjunctiva are located on the basal layer and have an oval and round shape. The mucus that they synthesize and excrete, binds into a kind of network that captures and fixes foreign bodies and bacteria. During blinking, the network breaks and shifts to the medial edge, removing debris and bacteria from the eye.
Goblet cells of the pancreas
Goblet cells are present in the excretory ducts of the pancreas. They are located not along the entire length of the ducts, but in their wide part. Here, the exocrine glands form the mucous membrane.
Parotid gland
The salivary gland is also saturated with goblet cells. They are located near the mouth and secrete mucus, which can put a chemical barrier to microbes. With age, the number of goblet cells in the parotid salivary glands decreases. The antimicrobial barrier weakens.
Feature Details
Goblet cells produce insoluble mucus called mucin. Mucin lines the mucous membrane, sometimes accumulating to a thickness of 1.5 mm. To form it, mucitogenic granules absorb water and swell. Goblet mucus has several functions. In the stomach, pancreas and intestines, it moisturizes the mucous membranes of organs, promotes the contents of the stomach and intestines, and is part of the process of parietal digestion. In the conjunctiva, in addition to hydration, it has a protective function, in the salivary glands it has a barrier function.
Goblet cell antibodies
In the normal state, antibodies to goblet cells are absent in the blood. If these antibodies are detected during a blood test from a vein, then the patient has ulcerative colitis. Therefore, the analysis of goblet cell antibodies is prescribed for the differential diagnosis of chronic inflammatory bowel diseases.