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.
Langerhans cells are cells that present antigen and are located on the mucosa and skin. They are always found in all the epidermis layers but are very rampant in the stratum spinosum. Langerhans can also be found in the blood vessels and the mucosa of the foreskin, mouth, and vagina.angerhans cells are cells that present antigen and are located on the mucosa and skin. They are always found in all the epidermis layers but are very rampant in the stratum spinosum. Langerhans can also be found in the blood vessels and the mucosa of the foreskin, mouth, and vagina.