Lab 19 Esophagus and Stomache: 1) Index 2) Introduction 3) Things to Identify 4) Upper Esophagus 5) Middle Esophagus 6) Lower Esophagus 7) Cardiac Stomach 8) Fundic Stomach 9) Pyloric Stomach 10) Stomach-Duodenal Junction 11) Comparison of Structures 12) Practical

 

STOMACH-DUODENAL JUNCTION

(PYLORIC SPHINCTER REGION)

 

# 114 - Stomach, duodenum, monkey (pyloro-duodenal junction), h-e

 

In this area, the circular muscle layer of the muscularis externa forms the pyloric sphincter.

The submucosal duodenal (Brunner's) glands are unique to the duodenum. What substance (s) do they secrete?

Goblet cells are interspersed among the columnar enterocytes (intestinal lining cells) of the duodenal mucosa. Compare this region with the mucosa of the stomach. Remember that the surface mucous cells of the stomach are not goblet cells. Does the duodenum have a serosa?

REFERENCES: Ross, p. 482 - 483 Wheater, p. 258, Fig. 14.14 DiFiore, p. 191, Fig. 12.11

 

This is an image of the end of the Pyloric Stomach (red arrow) where it meets the Duodenum (blue arrow), which is the first part of the small intestines. At this point the Inner Circular layer of muscle in the muscularis externa enlarges to become the Pyloric Sphincter, indicated by the green arrow. The black arrow is pointing to the point of transition between the two tissues. The key to knowing where the stomach ends and duodenum begins are in two important clues. First, where the Deep Gastric Pits of the pyloric stomach ends, and where the Brunner's Glands in the submucosa of the duodenum begin.

Red arrow - Pyloric Stomach

Blue arrow - Duodenum

Black arrow - Transition point

Green arrow - Pyloric Sphincter

Here is a closer look at the junction point. The red arrow is pointing to the Mucosa, of the Pyloric stomach with it's Deep Gastric Pits, indicated by the black arrows. The Blue arrow is pointing to the Mucosa of the Duodenum. The green arrow is pointing to the Pyloric Sphincter. The orange arrow is pointing to the beginning of the Submucosa of the duodenum. It is here where the Brunner's Glands (yellow arrows) are found, which gives the clue that the duodenum has begun and the stomach has ended.

Blue arrow -Mucosa of Duodenum

Red arrow - Mucosa of Stomach

Black arrow - Deep Gastric Pits

Orange arrow - Submucosa of Duodenum

Yellow arrows - Brunner's Glands

Green arrow - Pyloric Sphincter

 

Here is another look at the junction point showing the characteristics of each side. The black arrows are pointing to the Deep Gastric Pits of the Pyloric Stomach and the blue arrows are pointing to the Brunner's Glands of the Duodenum.

Black arrows - Gastric Pits

Blue arrows - Brunner's Glands

 

 

Pylori Sphincter

 

Pyloric Stomach / Duodenum Junction

 

Pyloric Stomach / Duodenum Junction