| THE PANCREAS. 1077 
Se 
contact with the lower portion of the gastric surface of the spleen. It usually presents an 
abrupt, blunt ending, in which case it is related to the spleen in the manner just described ; 
or it may be elongated and narrow, when it bends backwards around the outer aspect of 
the kidney, and beneath the base of the spleen. In either case it lies in contact below 
with the splenic flexure of the colon (Fig. 723). 
Peritoneal Relations of the Pancreas.—The posterior surface of the pancreas 
is entirely free from peritoneum. The other surfaces derive their peritoneal covering 
from the prolongation of the two layers of the transverse mesocolon, which latter is 
attached to the anterior border of the eland, from the tail to the neck. At this border 
the two layers separate (Fig. 707, p. 1048), the anterlor—derived from the small sac 
—passing backwards and upwards oyer the pe aeee surtace ; the posterior—derived 
from the large sac—turning downwards and backwards along the interior surface. 
As the transverse mesocolon is followed to the spi it ceases, as a rule, that is, its two layers 
fail to meet about the neck of the pancreas (Fig. 724). Beyond this tlie posterior surface of 
the colon is generally free from peritonewn, and is connected by areolar tissue to the front of the 
head of the gland. ‘Below the level of the colon the head is covered by the continuation down- 
wards of the peritoneum from the under surface of that gut. Often, however, the transverse 
mesocolon is continued to the right as far as the hepatic flexure, when the anterior surface of 
the head is then completely covered by peritonewn. 
Ducts of the Pancreas.— Almost invariably two ducts are found in the interior 
of the pancreas—the pancreatic duct proper and the accessory pancreatic duct. 
The pancreatic duct (ductus pancreaticus Wirsunei) begins near the tip of the 
tail by the union of small ducts from the lobules forming that part of the organ. 
From this it pursues a rather sinuous or zigzag course (Fig. 725) through the axis 
of the gland, at first running transversely to the right, until the neck is 
reached, then bending 
downwards towards the 
head. Here it approaches 
the second portion of the 
duodenum, and meeting 
the bile duet, the two 
pierce the inner wall 
the gut obliquely (for 
4 to 3 of an inch, 2250 Superior mesenteric artery 
18 mm.), and open, by a th ae ne ha 
common orifice on the Superior mesenteric veil 
bile papilla, about 33 or / 
4 inches (8°7 to 10 em.) yw wae at gee 
beyond the pylorus (see 
First part of 
duodenum 
Accessory 
/ pancreatic 
duct 
Common 
Be hie duet 
Panereatie duct 
Branch of 
accessory duct 
Fic. 725.—THE PANCREAS AND DUODENUM FROM BEHIND, with the 
1070 
p- (U). pancreatic duct exposed. 
In its course through The superior mesenteric vessels are also shown in section, passing forward, 
the glan d the duet surrounded by the recurved portion of the head of the pancreas. 
rece lves humerous 
branches, which join it, as a rule, at very open angles. These, as well as the main 
duct itself, are easily recognised by the whiteness of their walls, as contrasted with 
the darker colour of the eland tissue. The main duct receives branches from all 
portions of the pancreas, and towards its termination has attained a considerable 
size (namely, jth to ith of an inch—2°5 to 4 nm.—when fattened out, or some- 
what larger than a crow quill). 
The accessory pancreatic duct (ductus pancreaticus accessorius, Santorini) is a small 
and variably-developed duct (Fig. 725) which opens into the duodenum about ? of an 
inch above and somewhat in front of (¢.e. ventral to) the pancreatic duct. From the 
duodenum it runs to the left and downwards, and soon divides into two or more branches, 
one of which joins the pancreatic duct, the others pass down and receive the ducts from 
the lower part of the head. It is generally supposed that the current flows from this into 
the main duct, and not into the duodenum, as a rule, except in early life. 
Physical Characters and Structure of the Pancreas.—The pancreas is of a 
reddish cream colour, soft to the touch, and distinctly lobulated. The lobules 
are but loosely held together by their small ducts and by loose areolar tissue ; 
