Pancreas -- a large exocrine gland for secretion of digestive enzymes that are carried by a duct system to the duodenum. Small areas of endocrine tissue, the islets of Langerhans, will be studied later.

Examine sections of pancreas (slide 15, 44 and 154) with low power and observe the overall organization into lobules separated by CT septa with adipocytes, the pale-staining pancreatic islets (of Langerhans) surrounded by densely packed acini, and the excretory ducts (Fig. 16-8).

What are the cells that comprise most of each lobule called?

How do pancreatic acini and pancreatic islets differ structurally and functionally?

How are the cells of pancreatic ducts different and how are they similar to the same cells in salivary glands?

With the 40X objective, examine acini in an area where the polarized nature of the cells is apparent (Fig. 16-9)

• Note that the lumens of pancreatic acini are almost too small to see with the light microscope. Compare the appearance of acini with the electron micrograph in Fig. 16-10.

How does the pancreas neutralize the acidic chyme entering the duodenum from the stomach?

Next is the liver.