b. There are associated glands--the liver and the pancreas--which produce
additional enzymes to further the process.
c. Most digestion and absorption takes place in the small intestines.
6-9. ANATOMY OF THE SMALL INTESTINES
a. The small intestines are classically divided into three areas-- the duodenum,
the jejunum, and the ileum. The duodenum is C-shaped, about 10 inches long in the
adult. The duodenum is looped around the pancreas.
DUODENUM = 12 fingers (length equal to width of 12 fingers)
The jejunum is approximately eight feet long and connects the duodenum and ileum.
The ileum is about 12 feet long. The jejunum and ileum are attached to the rear wall of
the abdomen with a membrane called a mesentery. This membrane allows mobility and
serves as a passageway for nerves and vessels (NAVL) to the small intestines.
JEJUNUM = empty
ILEUM = lying next to the ilium (bone of the pelvic girdle; PELVIS = basin)
b. The small intestine is tubular. It has muscular walls which produce a
wave-like motion called peristalsis moving the contents along. The small intestine is
just the right length to allow the processes of digestion and absorption to take place
c. The inner surface of the small intestine is NOT smooth like the inside of new
plumbing pipes. Rather, the inner surface has folds (plicae). On the surface of these
plicae are finger-like projections called villi (villus, singular). This folding and the
presence of villi increase the surface area available for absorption.
6-10. LIVER AND GALLBLADDER
a. Liver Anatomy. The liver is a large and complex organ. Most of its mass is
on the right side of the body and within the lower portion of the rib cage. Its upper
surface is in contact with the diaphragm.
b. Liver Functions. The liver is a complex chemical factory with many
functions. These include aspects of carbohydrate, protein, lipid, and vitamin
metabolism and processes related to blood clotting and red blood cell destruction. Its
digestive function is to produce a fluid called bile or gall.
c. Gallbladder. Until needed, the bile is stored and concentrated in the
gallbladder, a sac on the inferior surface of the liver. Fluid from the gallbladder flows
through the cystic duct, which joins the common hepatic duct from the liver to form the