Enterosyyttien

Enterosyyttien is the Finnish genitive form of enterocytes, the absorptive epithelial cells in the intestinal lining. In English, enterocytes are the predominant cell type of the intestinal epithelium, lining the villi of the small intestine and, to a lesser extent, the colon. They form a continuous, highly polarized layer that serves as both a barrier and an active site of digestion and nutrient uptake.

Structure and location

Enterosyyttien are tall, columnar cells with an apical brush border formed by densely packed microvilli. This microvillar surface increases the absorptive area and hosts many membrane-bound enzymes and transporters. Tight junctions between adjacent cells create a selective barrier, while lateral surfaces contain transport proteins and channels essential for transepithelial transport.

Function

The primary role of enterosyyttien is nutrient absorption. They express transporters for sugars, amino acids, fatty acids, and vitamins, enabling uptake from the intestinal lumen into enterocytes and then into the bloodstream. Brush border enzymes, such as lactase and sucrase–isomaltase, further break down disaccharides. Enterocytes also participate in water and electrolyte absorption and contribute to mucosal immunity and barrier integrity.

Development and turnover

Enterosyyttien arise from stem cells in the crypts of Lieberkühn, differentiating as they migrate up the villus and mature. They are continuously renewed, with a typical turnover of a few days, ensuring a functional and selective intestinal barrier.

Clinical relevance

Disruption of enterosyytin function or structure can impair absorption, contributing to malabsorption syndromes or diarrhea. Conditions such as celiac disease, infections, or certain congenital disorders can damage the villous epithelium and brush border, reducing nutrient uptake and barrier effectiveness.

See also: intestinal epithelium, enterocytes, brush border, nutrient transporters.