The jejunum is the midsection of the small intestine, connecting the duodenum to the ileum. It is about 2.5 m long, and contains the plicae circulares, and villi that increase its surface area. Products of digestion (sugars, amino acids, and fatty acids) are absorbed into the bloodstream here.
Not to be confused with the cells of the islets of Langerhans, found in the pancreas, or Langhans giant cell.
Describe the cell types located in the crypts of Lieberkhan. These intestinal glands are lined by goblet cells and intestinal absorptive cells. Enteroendocrine cells are found along their lateral borders. At the bottom of the gland are Paneth cells (zymogenic cells). The paneth cells contain large granules in their apical cytoplasm which contain zinc and lysozyme.