288
UNIT 3
Organ Systems
Stomach
Figure 15-6.
Overview of the stomach.
H&E, insets (
upper left
)
3
5; (
lower left
)
3
9; (
right
)
3
7.
The
stomach
is a “J”-shaped hollow organ. It connects the
esophagus
and
duodenum
of the small intestine. The stomach initiates
digestion of food and temporarily stores food. It can be divided into four parts: the
cardia
,
fundus
,
body
, and
pylorus
. Histologically,
stomach tissue can be distinguished by its
mucosal glands
(glands in the mucosa). (1 and 2) The
cardia
connects to the esophagus,
and the
pylorus
connects to the duodenum. These two ends of the stomach have similar histological characteristics. The mucosal
glands of the cardia and pylorus are called
cardiac glands
and
pyloric glands
, respectively. Both contain many
mucus-secreting
cells
and produce mucus, which is a thick, gel-like material that coats the surface of the stomach and protects it from acidic gastric
uid. Mucus-secreting cells contribute a small volume to the gastric juices. (3 and 4) The
fundus
and
body
of the stomach form the
largest part of the stomach (about two thirds). The mucosal glands in this region are called
fundic (gastric) glands
. These glands
are composed mainly of
parietal
and
chief cells,
which produce large volumes of gastric juices. A small number of various types of
enteroendocrine cells
are found at the base of the gastric glands. The gastric juices contain primarily
water
,
HCl
,
mucus
,
pepsin
,
IF
,
rennin
, and
lipase
. This is a highly acidic fl uid and plays an important role in digesting food.
Fundus of stomach
Pylorus of stomach
Esophagus
Fundus
Body
Gastric
rugae
Serosa
Submucosa
Mucosa
Oblique
muscle
Circular
muscle
Cardia
Longitudinal
muscle
Pylorus
Duodenum
Esophagogastric
junction
Stomach
I. Cardia
A. Cardiac glands
B. Mucus-secreting cells (produce mucus and lysozyme)
II. Fundus and Body
A. Fundic (gastric) glands
B. Mucous neck cells (secrete mucus)
C. Parietal cells (secrete HCl and gastric IF)
D. Chief cells (secrete pepsinogen, rennin, and lipase)
E.
Enteroendocrine (diffuse neuroendocrine) cells (release,
e.g., gastrin, histamine, and serotonin)
III. Pylorus
A. Pyloric glands
B. Mucus-secreting cells (produce mucus and lysozyme)
C. Enteroendocrine cells
D. G cells (secrete gastrin)
E. D cells (release somatostatin)
previous page 303 Dongmei Cui -  Atlas of Histology with Functional and Clinical Correlations 2011 read online next page 305 Dongmei Cui -  Atlas of Histology with Functional and Clinical Correlations 2011 read online Home Toggle text on/off