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. The islets of Langerhans are the endocrine (endo= within) cells of the pancreas that produce and secrete hormones such as insulin and glucagon into the bloodstream. The pancreatic hormones, insulin and glucagon, work together to maintain the proper level of sugar (glucose) in the blood.