ABSTRACT
The pancreas has two quite distinct functions. Many, though not all, investigators believe that both components of this organ are derived from the same primitive cells. A substantial number of recent studies would appear to indicate that the pancreas contains endodermally derived pancreas-specific precursor cells and that both the islets and the parenchymal acinar tissues are in fact derived from a common precursor (see below).1,2 While one of the roles of the pancreas is as an exocrine organ, and therefore part of the digestive system, its other role is that of an endocrine organ. In the human, its development and gross anatomy are relatively easily understood, principally because its various component parts are reasonably well delineated. In rodents, the gross anatomy of the pancreas is far less easily determined, as it consists of a series of irregular lobes and lobules that extend to occupy the available space between a number of the intra-abdominal viscera. More particularly, its component parts in rodents are quite difficult to define both during the pre-and early post-natal period and in the adult. The exocrine part of the gland produces a secretion with a relatively high pH (range 7.5-8.8). The low pH of the gastric contents (adult human males, average pH value 1.92; adult human females, average human pH value 2.59) tends to be neutralized by the alkalinity of the pancreatic and biliary secretions (hepatic bile pH range 6.2-8.5; gallbladder bile pH range 5.6-8.0).3
