CHAP. III.] MINUTE STRUCTURE OF THE PANCREAS. 



189 



so called, or Duct of Wirsung*, empties itself, in man, into the duo- 

 denum between three and four inches below the pylorus by an orifice 

 common to it and to the common bile-duct; the second, very small, 

 accessory pancreatic duct, communicates with the first by one or 

 more anastomosing branches and usually has a separate opening into 

 the duodenum. In most animals the chief duct of the pancreas 

 opens into. the intestines with, or very near to, the opening of the 

 common bile-duct. In some animals however, as in some monkeys 2 , 

 in the ox, the guinea-pig, the rabbit, the principal duct empties 

 itself below the orifice of the bile duct. In the last-named animal 

 the arrangement has been particularly studied by Claude Bernard, 

 who has shewn that whilst the accessory duct usually opens by a 

 common orifice with the bile duct, the principal duct empties into 

 the intestine 35 centimetres below that point 3 . 



Minute Structure of the Pancreas*. 



The pancreas used to be described as a compound saccular or 

 racemose gland. The observations of Latschenberger 5 and Heidenhain 

 have drawn attention to the fact, however, that the pancreas is more 

 properly a compound tubular gland, i.e. if we follow its branching 

 ducts we find them terminating in blind tubes and not in sacculated 

 recesses. 



The gland possesses a capsule of connective tissue whence proceed 

 inwards septa which penetrate the organ and support its constituent 

 lobes and lobules. The interlobular connective tissue supports the 

 blood-vessels, the nerves, and the lymphatics of the gland. 



Structure of 

 the ducts of 

 the pancreas. 



The pancreas possesses in most animals two, in some 

 more than two, excretory ducts. These ducts are lined 

 by columnar epithelium, which lies upon a basement 

 membrane. On the outer side of this basement membrane, there is 

 no inconsiderable amount of fibrillar connective tissue, and some in- 

 voluntary muscular fibres. The lobar ducts communicate with the 

 excretory ducts, the former proceeding outwards lead to intra- 

 lobular ducts, and these again to so-called intermediary ducts which 

 communicate directly with the alveoli. 



1 Wirsung was an anatomist of the 17th century who first observed and delineated 

 the pancreatic duct. He is said to have died by the hands of an assassin in 1643, the 

 same year in which he sent a copy of his engraving of the pancreatic duct to Riolan. 

 Claude Bernard, Lemons de Physiologic Experimental*, Vol. n. (1856), p. 171. 



2 See Milne Edwards, Lemons sur la Physiologic et V Anatomic Compares (1860), 

 Vol. vi. p. 511. 



3 Claude Bernard, op. cit., pp. 270 and 271. 



4 In his description of the pancreas the author has followed, in several cases almost 

 verbatim, Professor Klein's account in the Atlas of Histology, and Professor Heiden- 

 hain's in Hermann's Handbuch (Vol. v. p. 173), which is based upon his own and 

 Langerhans's observations. 



5 Latschenberger, quoted by Heidenhain, Hermann's Handbuch, Vol. v. p. 173. 



