The tail of the pancreas, located anatomically left near the hilum of the spleen, is not simply an anatomical distinction. The tail is the only part of the pancreas which contains Pancreatic Polypeptide (PP) cells, which are responsible for secreting pancreatic polypeptide to coordinate exocrine and islet enzyme release. PP cells are found in the tail's periphery. Beta cells and delta cells are found in the central part of the tail as with the rest of the pancreas. The cells described above are located exclusively in the islet cells; their secretions reach exocrine portions of the pancreas via the capillary network surrounding the islet cell populations. [WP,unvetted]. [ http://en.wikipedia.org/wiki/Tail_of_pancreas ]