How to Dissect a Frog

Dissecting a frog can be a snap with the right tools.

At some point in your educational career, you may have to dissect a frog in science class. As a member of the class Amphibia, frogs live sometimes on land, but reproduce in water. They have unique outside features, including two nostrils, eardrums and eyes. The eyes, however, each have three lids, the third of which is transparent. Before dissecting, you will have to study the exterior of your frog and identify its outer parts. Then you can begin to cut.

Things You'll Need

• Safety goggles
• Gloves
• Apron
• Forceps
• Preserved frog
• Dissecting pins
• Dissecting tray
• Paper towels
• Scissors
• Dissecting needle
• Frog anatomy diagram

Instructions

1. Put on your goggles, gloves and apron.

2. Place the frog in a tray, on its back, and pin down its legs.

3. Cut the hinges of the frog's mouth and open it wide.

4. Use your probe and diagram to locate any necessary structures inside the mouth.

5. Using your frog anatomy diagram, look for the frog's cloaca -- or large intestine -- between its hind legs, and use forceps to the lift the skin in the area.

6. Using scissors, cut along the center of the body from the large intestine to the lips.

7. Pull back the skin and pin it flat. If you need to, cut toward the side at each leg to make this easier.

8. Cut through the muscles and breast bone to open the body cavity.

9. Using your probe and scissors, remove the intestines and liver. Use your frog anatomy diagram to help you locate these organs.

10. Consulting your diagram, remove the connective tissue on top of the red kidneys, the peritoneal membrane.

11. Remove the red kidneys.

12. Slice open a thigh and observe the leg muscles.

13. Dispose of your materials according to your teacher's instructions.

Tips & Warnings

• If your frog is a female, you may need to remove eggs once you open up the body cavity.

• Don't forget to wash your hands thoroughly after dissection. Do not dissect without an adult's supervision.

References

• Biology Junction: Frog Dissection
• Takdan Aralin: Dissecting a Frog; Feb. 2009

Resources

• Read this Article in Spanish
• Net Frog Dissection