Name: _________________________
Date: __________________
Lab: The Structure of a Frog Leg
Introduction:
Similar in some respects to the human leg, a frog leg is composed of numerous different cells, tissue, and
organs. These body parts interact and cooperate to allow a frog to perform a variety of activities such as
jumping, leaping, and sitting. In this investigation, the various tissues and structures of the leg will be located
and described.
Materials:
 Frog leg
 Dissecting pan
 Scalpel
 Forceps
 Dissecting probe
 Paper towel
 Rubber gloves
Procedure:
1. Place a frog leg in your dissecting pan. Examine the skin of the frog. What does it look like?
2. What protein in the skin is contributing to the color?
CAUTION: Scalpels are very sharp! Carefully remove the skin by cutting a superficial incision down the inner
thigh and peeling the skin back. Be careful not to cut too deep and disturb underlying muscle tissue. Yellow
masses may be found on the inside surface of the skin.
What type of tissue are these masses?
3. Once the skin has been pulled back, examine all of the muscle on the frog leg. Be sure to identify all of
the muscles in the given diagram. Place a check mark by the muscles you are able to view and
determine whether they are also located in the human body.
Frog Muscles:
 Adductor longus
 Triceps femoris
 Adductor Magnus
 Sartorius
 Semimemranosus
 Gracilis major
 Gastrocnemius
 Iliotibularis
 Peroneus
 Tibialis longus
 Achilles Tendon
Found in the Human Body?
4. Observe the tough white tissue that is found at both ends of the muscle. It extends from the muscle
ends to the bone. That tissue is called a tendon.
5. With a scalpel, carefully cut out the triceps femoris with its tendons and set it aside in the dissecting
pan. Make a diagram of the muscle with its tendons and label each of them.
6. Observe the thin white tissue that covers the muscle. This is connective tissue, or the fascia. Is the
connective tissue firmly or loosely attached to the muscle?
7. Carefully remove all the muscles and tendons using the same procedure as you did in step 5.
8. Carefully look for the blood vessels. These are thick, red, threadlike strands. Also look for nerves.
Nerves are thin, white threadlike strands that are found nearest the bones. How do the diameters of
the nerves and blood vessels compare?
9. Your frog leg should now have all the muscles and tendons removed. Use your scalpel to clear away
any muscles or tendons remaining.
10. Examine the joints. The ligaments are tough, white tissue holding the two bones together. With your
hands, try to break the ligaments and separate the bones that connect the thigh and the lower leg. Do
the bones separate easily? _________________________________________
Conclusion/Analysis:
1. The meat of the leg and thigh consists of what type of tissue? When you eat a chicken leg what type of
cells are you actually eating?
2. In what ways are muscle and bones similar? Different?
3. In what ways are tendons and ligaments similar? Different?
Muslces of the frog leg
Muscles of the human leg