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.
PancreasâIslets of Langerhans. The pancreas is a long, soft organ that lies transversely along the posterior abdominal wall, posterior to the stomach, and extends from the region of the duodenum to the spleen.This gland has an exocrine portion that secretes digestive enzymes that are carried through a duct to the duodenum.he endocrine portion consists of the pancreatic islets, which secrete glucagons and insulin. Alpha cells in the pancreatic islets secrete the hormone glucagons in response to a low concentration of glucose in the blood.