679
CHAPTER SEVENTEEN
Digestive System
M
olly G., an overweight, forty-seven-
year-old college administrator and
mother of four, had pain in the upper-
right quadrant of her abdomen (see fig. 1.24b).
Sometimes the discomfort seemed to radiate
around to her back and move upward into her
right shoulder. She usually felt this pain after her
evening meal, but it occasionally happened at
night, awakening her. After an episode of severe
pain accompanied by sweating (diaphoresis)
and nausea, Molly visited her physician, who dis-
covered tenderness in the epigastric region (see
fig. 1.24a). She decided that Molly’s symptoms
symptoms could indicate
acute cholecystitis
—an
inF
ammation of the gallbladder. Molly needed a
cholecystogram
—an X ray of the gallbladder.
Molly took tablets containing a contrast
medium the night before the X-ray procedure,
which allowed time for the small intestine to
absorb the substance and it to reach the liver and
be excreted into the bile. Later, the bile and con-
trast medium would be stored and concentrated
in the gallbladder and would make the contents
of the gallbladder opaque to X rays.
Molly’s cholecystogram revealed several
stones (calculi) in her gallbladder, a condition
called
cholelithiasis
(see ±
g. 17.29)
.
Molly’s symp-
toms were worsening, so her physician recom-
mended
cholecystectomy
—surgical removal of
the gallbladder.
An incision was made in Molly’s right sub-
costal region and her gallbladder excised from
the liver. ²ortunately, the cystic duct and hepatic
ducts did not have stones (see ±
g. 17.26).
Unfortunately, Molly’s symptoms persisted
following her recovery from surgery. So her sur-
geon ordered a
cholangiogram
—an X-ray series
of the bile ducts. This study showed a residual
stone at the distal end of Molly’s bile duct (see
±
g. 17.23).
The surgeon extracted the residual stone
using a
f
ber-optic endoscope,
a long, F
exible tube
passed through the esophagus and stomach and
into the duodenum. This instrument enables a
surgeon to observe features of the gastrointes-
tinal tract directly through the eyepiece of the
endoscope or on a monitor. A surgeon can also
perform manipulations using specialized tools
passed through the endoscope to its distal end.
In Molly’s case, the surgeon performed
an
endoscopic papillotomy
—-an incision of the
hepatopancreatic sphincter by applying an elec-
tric current to a wire extending from the end of
the endoscope (see ±
g. 17.23). She then removed
the exposed stone by manipulating a tiny bas-
ket at the tip of the endoscope. Many patients
undergo only the endoscopic procedure to
remove the gallbladder, performed on an outpa-
tient basis.
17.4
CLINICAL APPLICATION
Gallbladder Disease
Chyme with
fat enters
duodenum
1
Bile passes down the cystic duct
and bile duct to duodenum
4
Hepatopancreatic sphincter relaxes
and bile enters duodenum
5
Gallbladder
Bile duct
Cystic duct
Common
hepatic duct
Duodenum
Pancreatic
duct
CCK stimulates
muscular layer
of gallbladder
wall to contract
3
Bloodstream
Cells from the
intestinal mucosa
secrete the hormone
cholecystokinin (CCK)
into the bloodstream
2
Hormonal
signals released
into bloodstream
Stimulation of
effector organ
FIGURE 17.30
²atty chyme entering the
duodenum stimulates the gallbladder to release bile.
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