The pancreas is a mixed exocrine and endocrine gland. Most of the pancreas (~95%) is exocrine cells that secrete digestive enzymes into the duodenum. Scattered throughout the pancreas are clusters of only a few cells to several thousand cells (2 to 5%) that secrete hormones into the blood that regulate glucose.
The endocrine cells occur as irregular cords surrounded by fenestrated capillaries.
This specimen contains an excellent example of a parasympathetic ganglion that is easily confused with small islets at low magnification. However at higher magnification, the typical structure of an automatic ganglia is evident.