The Dissection of the Stomach

April 14th

Focus of Procedure:
Identify and observe the parts of the stomach and gain an understanding in the stomach's primary functions.

Materials:
-Scalpel
-Tweezers
-Teaser Needle
-Plastic Bag
-Paper Towel(s)

Procedure:
1) If you have not already done so, remove the greater and lesser momentum, which is the lining over the intestines. Removing this will provide you with a better view of the organs in the peritoneal cavity (digestive system). Include a picture of the greater and lesser omentum.
2) Locate the stomach and take a picture of the stomach still attached to the peritoneal cavity.
3) Identify the esophageal sphincter and use your scalpel to cut through it, disconnecting the fondus (top of the stomach) from the esophagus. Cut the esophageal sphincter right above the cardia, which is the tissue between the esophageal sphincter and the stomach. Take a picture of the esophageal sphincter, the cardia and the fondus. Also identify the lesser and greater curvature (the sides of the stomach). The lesser curvature is the left side of the stomach and the greater curvature is the right side of the stomach. It is important to leave the stomach in its original position in order to correctly identify the parts of the stomach.
4) Observe the pyloric sphincter and use your scalpel to cut through it, disconnecting the bottom of the stomach from the small intestine. Take a picture of the pyloric sphincter and the bottom of the stomach (right where it was disconnected).
5) Now that the stomach has been removed from the peritoneal cavity, use your scalpel to cut horizontally across the top of the stomach. Do not cut the stomach entirely in half, the purpose of cutting the stomach is to observe the undigested food (if there is any) inside the cat's stomach. Fold the stomach open and take a picture of the inside of the stomach and all the undigested food (if there is any).
6) Remove the undigested food from the stomach using a teaser needle or your hands. Put anything you find inside the stomach onto a paper towel and take a picture of your findings.
7) Wash off the inside of the stomach in the sink, then place the stomach on the table for a second picture of the inside. Be sure to capture the rugae of the stomach in this picture. The rugae are the gastric folds that line the inside of the stomach.
8) Take as many more pictures as you wish to take. Throw out the undigested food on the paper towel and place the stomach in the plastic bag.

Data and Observations:
This procedure was very easy as well as interesting. Semara's esophageal sphincter, stomach and pyloric sphincter were quickly found and in very good condition. She had a bit of undigested food in her stomach, which looked like cat food. Once the digested food was removed, I was able to observe the rugae, or gastric folds, more closely. Overall Semara had a very healthy stomach and I had no difficulty identifying and dissecting the parts of her stomach. Pictures from this lab are labeled and shown below.

THE PERITONEUM/ PERITONEAL CAVITY:

THE STOMACH:

Conclusion:
Looking inside the stomach was very exciting! I was able to observe the inside of the stomach and study the rugae or gastric folds. I was also able to earn a better understanding of how food enters and leaves the stomach. I learned that food travels down the esophagus and then through the esophageal sphincter to reach the stomach. Once the food is digested it goes through the pyloric sphincter, which leads to the small intestine. I did not experience any difficulty identifying the parts the stomach but i did have trouble remembering which sphincter was which in my pictures. Observing the peritoneal cavity was very cool and gave me a better understanding of the digestive system!