The objective of this lab is to dissect a raw chicken leg, including thigh and knee joint, in order to better understand the muscle and skeletal system. This includes a hands on look at muscles, bones, tendons, ligaments, fatty tissues and connective tissues.
Materials involved consisted of the chicken leg and thigh, a knife, scissors, gloves, a bowl with soap and water, wax paper and aluminum foil
I began by using the scissors and the knife to peel away the skin from the chicken leg and thigh. I noted as I did this, a clear, thin membrane of connective tissue, as well as some fatty tissue. The fatty tissue is found in clumps, and is very difficult to remove. Fatty tissue is responsible for both insulation, and the storing of nutrients. The scientific name for fatty tissue is Adipose Tissue.
Upon removing the skin, I can see the pink colored muscles. I note there appear to be at least several different muscles present, and they are defined by the direction in which the tissues run. I observed one muscle at the edge of the leg, which appears to be responsible for flexing the foot up and down. This is likely due to the up and down pattern which runs parallel to the leg bone. I observed a similar muscle behind the leg bone, which appears to be the calf muscle. I also observed the thigh muscles, which are responsible for leg movement.
Upon pulling the muscles away from the leg bone, I noted the white colored tendons. The tendons are long, thin strips of connective tissue which are attached between the muscle and the bone. They attach skeletal muscles to bones. Skeletal muscles are those muscles which are attached to bones, and are responsible for movement.
Operation of the knee joint is an example of a flexion and extension movement.
Upon removing the surrounding tissue from the joint itself, I was then able to cut through the joint. I could see the leg bone ended in a rounded shape, fitting into the cup like area of the knee joint. This is an example of a Hinged Synovial Joint. The rounding of this joint, as well as the fluids and membranes involved with the joint provide cushioning and reduce friction to delay breakdown of the joint. Joint cartilage is found in this area to reduce friction as well. This would occur more quickly without these, as the bones would grind together directly. Arthritis of the joint is another result of joint breakdown from friction.
While cutting through the joint, I also cut into the end of the leg bone, and I could see a red tissue I believe was red bone marrow. It can be seen in the above photo. This marrow contains stem cells, which are responsible for red and white blood cells, and platelets. Osteocytes are also included in the compact bone.
In conclusion, upon completing my dissection, I discovered I had a much greater grasp of how the things I was learning about actually appeared and worked together. I was able to observe some of the functions hands on, and this was a great enhancement to what I have been learning in this unit!