850
UNIT 4
Maintenance of the Body
23
Te
alimentary canal
, also called the
gastrointestinal (GI)
tract
or gut, is the continuous muscular tube that winds through
the body from the mouth to the anus. It
digests
food—breaks it
down into smaller fragments (
digest
5
dissolve)—and
absorbs
the digested fragments through its lining into the blood.
Te organs of the alimentary canal are the
mouth
,
pharynx
,
esophagus
,
stomach
,
small intestine
, and
large intestine
. Te large
intestine leads to the terminal opening, or
anus
. In a cadaver, the
alimentary canal is approximately 9 m (about 30 F) long, but in a
living person, it is considerably shorter because of its muscle tone.
±ood material in this tube is technically outside the body because
the canal is open to the external environment at both ends.
PART 1
Overview of the Digestive
System
Describe the function of the digestive system, and
differentiate between organs of the alimentary canal and
accessory digestive organs.
Te organs of the digestive system fall into two main groups: (1)
those of the
alimentary canal
(al
0
ĭ-men
9
tar-e;
aliment
5
nour-
ish) and (2)
accessory digestive organs
(Figure 23.1)
.
Mouth (oral cavity)
Tongue*
Esophagus
Liver*
Gallbladder*
Anus
Duodenum
Jejunum
Ileum
Small intestine
Parotid gland
Sublingual gland
Submandibular
gland
Salivary glands*
Pharynx
Stomach
Pancreas*
(Spleen)
Transverse
colon
Descending
colon
Ascending
colon
Cecum
Sigmoid colon
Rectum
Appendix
Anal canal
Large intestine
Figure 23.1
Alimentary canal and related accessory digestive organs.
Organs with
asterisks are accessory organs. Those without asterisks are alimentary canal organs (except the
spleen, a part of the lymphatic system). (For a related image, see
A Brief Atlas of the Human
Body
, Figure 64a.)
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