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.
islets of Langerhans - cell clusters in the pancreas that form the endocrine part of that organ; secrete insulin and other hormones. islands of Langerhans, isles of Langerhans. ductless gland, endocrine gland, endocrine - any of the glands of the endocrine system that secrete hormones directly into the bloodstream.