3-11. THE ACCESSORY ORGANS OF DIGESTION
The accessory organs of digestion are the liver, the gallbladder, and the
pancreas (figures 3-1 and 3-5).
a. The Liver. The liver is the largest gland in the body, weighing ordinarily from
3 to 4 pounds in men and somewhat less in women. Its consistency is like that of a wet
sponge and its color is dark reddish brown. The liver is divided into a right lobe and a
smaller left lobe. It is in the upper right quadrant of the abdominal cavity and lies
immediately beneath the diaphragm. It occupies almost the whole of the right
hypo-chondrium and the greater part of the epigastrium; it frequently extends into the
left hypochondriac region (figure 1-7). Two tubes of nearly equal size issue from the
right and left lobes of the liver. These two tubes unite to form the common hepatic duct.
The principal condition for which the liver may be examined radiographically is hepatic
b. The Gallbladder.
(1) The gallbladder is a pear-shaped musculomembranous sac situated on
the undersurface of the right lobe of the liver. It is about 3 to 4 inches in length and
about 1-1/2 inches in diameter at its largest part. It serves as a reservoir for bile,
accommodating about 30 to 35 milliliters of concentrated bile. The gallbladder is
divided into a fundus, a neck, and a body. The fundus of the gallbladder normally is
situated under the right lobe of the liver at the end of the right ninth costal cartilage near
the junction of the right vertical and upper horizontal lines (figure 1-9). The cystic duct
runs backward and downward from the neck of the gallbladder and joins the common
hepatic duct to form the common bile duct. The cystic duct is about 1-1/2 inches long
and contains a system of valves within its lumen, called the "spiral valve of Heister."
The common bile duct is about 3 inches long and communicates with the duodenum by
way of the ampulla of Vater and the sphincter of Oddi.
(2) The position of the gallbladder varies with the type of body habitus and
tends to shift with changes in posture and with the stages of respiration.
c. The Pancreas. The pancreas is an elongated gland in the epigastric and left
hypochondriac regions of the abdomen. The head of the pancreas is lodged within the
curve of the duodenum. The secretion of the pancreas is carried by the pancreatic duct
into the duodenum (figure 3-5).