Chicken Leg Dissection Lab

To get a better feeling for how muscles and bones work we were assigned to do a dissection of a chicken leg.  By completing this exercise we were able to look at how the different systems are constructed and how they interact to make movement possible in different kinds of joints.

Ready to start the dissection we have a full leg quarter with skin still intact, and the tools.

The first step was to remove the skin.  As it's peeled back you can see the clear connective tissue that secures the skin to the underlying muscles.

Now that the skin has been removed, the muscles of the leg are clearly visible.

The muscles within the leg can be separated into bundles.  There are muscle bundles that run parallel to, and along the bone, and others that run diagonally over the underlying parallel muscles.

At joints there are muscles that cross the joint to aid in it's movement and stabilization.  This Photo shows a muscle from the thigh (held on the left) that crosses the joint, and attaches diagonally under the muscles of the lower leg.

Muscles are attached to the bones by tendons like the one shown here.  The origin of a tendon is stationary and does not move when it's muscle contracts, while the insertion is moveable.

Once the tendons are cut at one end, the muscles peel back to reveal the bones.  The tibia is obviously visible, while the fibula on the right of the leg is much smaller and more difficult to see.

The leg muscles, when examined individually have stripes across them indicating that they are striated skeletal muscles.  Although I was unable to locate them in my specimen nerves run along the muscle tissues and serve to send messages to control the muscle and thus the movement of the animal.

After pulling away the knee cap (top left), you can see into the knee joining and the ligaments that hold the bones together are clearly visible.  Tendons are made of collagen which makes them strong and flexible.

After removing the muscles from the entire leg the bones and joints are clearly visible.

Although we didn't open the bones in this dissection, they are full of tissue called marrow.  This soft material is comprised of different cells.  Yellow bone marrow is primarily fat cells.  Red bone marrow contains hematopoietic stem cells, which are undifferentiated cells that ultimately differentiate in

to different kinds of blood cells.  Bone marrow also contains mesenchymal stem cells that differentiate into many other types of cells.

This diagram shows the basic leg anatomy of a chicken and the two different kinds of joints present.  The hinge joint of the knee functions like a hinge and allows the lower leg to swing, while the hip joint is a ball and socket that allows for rotation, and much greater movement.