The pancreas has a poorly defined capsule. It is covered by thin areolar connective tissue capsule. This capsule gives rise to the connective tissue septae that divide the pancreas into lobules. Blood vessels, nerves, lymphatics and ducts transverse through the septae. Each lobule is supplied by a principal small artery.
Acinar cells constitute the majority of the organ.
The cells form rounded or elongated acini usually at the ends of the intercalated ducts. Normal acinar cells are large, pyramidal shaped cells with a single nucleus. The nucleus lies close to the base of the cell which rests on the basal laminae. The nucleus is round with clumped chromatin present. The apical portion of the cell is filled with eosinophilic zymogen granules.