Download Digestive system

Team Members: ____________________________________________________________
Group Name: ____________________________________
Cat Dissection: Digestive System Review
Objective: Identify & compare the gross anatomy of the cat’s digestive system to that of a human’s.
Materials: The following materials should be used:
1. Embalmed cat in plastic bag & dissection tray
2. Dissecting tools (heavy duty scissors, scalpel, probe, 2 dissecting needles, forceps)
3. Name tags & String
4. Latex surgical gloves
Procedure:
A. Mouth Cavity
1. Cut through the muscles & skin at the corner of the mouthy, then press down the lower jaws with your
fingers.
2. Cut the angle of the mandible with bone cutters.
3. Located the following structures:
a. cheeks & lips
b. vestibule, space between the lips & teeth.
c. tongue:
i. frenulum, connective tissue & skin holding the tongue to the floor of the mouth.
ii. filiform papillae, spine-like structures on the upper surface of the tongue.
iii. fungiform papillae, mushroom-shaped structures at the back of the tongue & among the filiform
papillae.
iv. pharynx, found at the back of the oral cavity & actually is the throat.
B. Body cavity & Viscera
1. Make an incision from the sternum to the pelvic region just lateral to the linea alba. Do not cut any of the
underlying organs.
2. Make a second incision at right angles to the first just below the diaphragm & again at the posterior end of
the abdominal cavity.
3. Extend this incision nearly to the backbone, & turn back the flaps thus formed.
4. Locate the following:
Diaphragm
Esophagus
Liver (just posterior to the diaphragm)
Gall Bladder (imbedded w/in the right lobe of liver)
Stomach
Spleen (flat red organ lying to left of greater curvature of the
Ileum
Pancreas
Mesentery (double membrane supporting the small
intestine to the dorsal body wall)
Colon
Cecum
Ascending Colon
stomach)
Small Intestine
Descending Colon
Duodenum
Rectum
Jejunum
Anus
5. Remove the stomach by making an incision at the cardioesophogeal sphincter and another inferior incision at
the pyloric sphincter. Carefully remove the stomach from the abdominal cavity.
6. Make a horizontal (frontal) incision separating the stomach into a front & back halves. (Look for any worms
or other parasites that may be present in the stomach.)
7. What is inside the stomach of your specimen? _______________________________________ Note the
rugae on the inner wall of the stomach which look like longitudinal ridges. What does the rugae help with? ___
__________________________________________________________________________________________
8. What are the 4 regions of the stomach called? _________________________________________________
9. Now, remove the small intestine from the body cavity. Make an incision at the ileocecal valve (the terminal
end of the small intestine. The ileum is more tightly coiled than the first 2 parts of the small intestine).
Most of the food is absorbed through the walls of the ileum. Peyer’s Patches, small lymph nodes, appear as
light colored spots, on the inner wall of the intestine. Villi are fingerlike projections in the wall of the ileum.
10. Measure the small intestine form the duodenum to the ileum. It is _________________inches long.
11. Make an incision in the ileum wall, wash out the contents, & pin/identify the villi. Look for worms or other
parasites. You may find both round worms & tapeworms.
12. Now make an incision into the descending colon & look inside. What do you see? ___________________
_________________________________________________(remember, there are NO villi in the colon).
Questions:
1. What does the gall bladder do? _____________________________________________________________
2. What color is the gall bladder? ________________________________________________________
3. What does the liver do during digestion? _________________________________________________
4. How many canine teeth do the cat & human have total in their upper & lower jaws. ___________________
5. What is the passageway for air & food? ______________________________________________________
6. What is the muscular & tendinous wall separating the abdominal & thoracic cavities? __________________
7. What is the “gate keeper” of the esophagus called? ______________________________________________
8. What color is the liver? ______________________How many lobes does the cat liver contain? _________
9. How many lobes does the human liver contain? ___________________
10. What is the middle section of the small intestine called? ________________________________________