i8 4 



TEXT-BOOK OF PHYSIOLOGY. 



PANCREAS. 



The pancreas is a long flattened gland, situated deep in the abdominal 

 cavity, lying just behind the stomach. It measures from fifteen to twenty 

 centimeters in length, six in breadth, and two and a half in thickness. Itfis 

 usually divided into a head, body, and tail. The head is directed to the right 



Pancreatic ducts. 



Common bile-duct- 



Tail. 



FIG. 79. PANCREAS AND DUODENUM REMOVED FROM THE BODY AND SEEN FROM 

 BEHIND. THE GLAND is CUT TO SHOW THE DUCTS. (Landois and Stirling.} 



side and is embraced by the curved portion of the duodenum; the tail is di- 

 rected to the left side and extends as far as the spleen (Fig. 79) . The pancreas 

 communicates with the intestine by means of a duct. This duct commences 

 at the tail and runs transversely through the body of the gland. As it ap- 

 proaches the head of the gland it gradually increases in size until it measures 



about two or three millimeters 

 in diameter. It then curves 

 downward and forward and 

 opens into the duodenum. In 

 its course through the gland it 

 receives branches which enter 

 it nearly at right angles. The 

 pancreas is richly supplied with 

 blood-vessels and nerves, the 

 latter coming from the solar 

 plexus. 



Histologic Structure. In 

 its structure the pancreas re- 

 sembles the salivary glands. It 

 consists of a connective-tissue 

 framework which divides the 

 gland tissue into lobules. Each 

 lobule is composed of a number 

 of acini or alveoli, more or less 

 elongated or tubular in shape. Each acinus gives origin to a small duct 

 which, uniting with adjoining ducts, forms the lobular duct, which becomes 

 tributary to the main duct. The acinus is lined by a layer of cylindric 

 epithelial cells characterized by a difference in structure between their cen- 



FIG. 80. FIG. 81. 



ONE*SACCULE OF THE PANCREAS OF THE RABBIT 

 IN DIFFERENT STATES OF ACTIVITY. Fig. 80. After 

 a period of rest, in which case the outlines of the cells 

 are indistinct and the inner zone i. e., the part of the 

 cells (a) next the lumen (c) is broad and filled with 

 fine granules. Fig. 81. After the gland has poured 

 out its secretion, when the cell outlines (d) are clearer, 

 the granular zone (a) is smaller, and the clear outer 

 zone is wider. (Kuhne and Lea.} 



