As I said in my post on dissecting chicken wings, the dissection of higher animals gives us the opportunity to observe and probe internal structures that resemble those in our own bodies. The wing makes a nice analog to the human arm, and the chicken leg makes an equally nice analog to a human leg. In fact, chicken legs are larger, with parts that are easier to examine and work with, and the skin comes off much more easily. A drawback is that the feet aren’t normally included, although you can buy those separately, as I mentioned in my post on the workings of the hand.
Supermarkets normally sell “leg quarters”, which consist of a thigh and drumstick still united. This is what a leg quarter looks like:
Just as the pieces of a wing correspond to those in a human arm, the pieces of a chicken leg correspond to those in a human leg. The muscular section closest to the body is the thigh, the middle section (the drumstick) corresponds to the human lower leg, and if the foot were still attached, it would follow the drumstick. As with the wing, we need to remove the skin to discover the muscle structure underneath. Fortunately, the skin comes off of a leg much more easily than from a wing. You don’t even need scissors. You can reach inside the hip end with your fingers and pry the skin free from the underlying tissue, then gradually peel the skin inside out off the ankle end, like taking off a sock. This is what a skinned leg looks like:
The biceps and triceps on the wing are single, clearly identifiable muscles. The larger muscles on a chicken thigh do correspond to the quadriceps and hamstring muscle groups in a human leg, but like the quadriceps and hamstrings, they are bundles of several inter-grown muscles, and they aren’t as easy to identify.
From this point on, I don’t have a systematic procedure to offer. Think of the rest of the dissection as an exploration, in which you gradually disassemble the wing to see what you can see. Some of the things I have observed are as follows:
Unlike the wing muscles, the muscles in the leg are relatively easy to pry apart from one another and examine separately. If you start from the ankle, you might be able to produce something like this:
There is a tough band of cartilaginous material around the ankle, which I can only guess corresponds to the retinacula around human wrists and ankles, and which contains passages through which tendons slide, much like the carpal tunnel in the human wrist. If you cut this and pull it away, and gradually pry, squeeze, or pull apart the muscles, you should find that the drumstick is a bundle of muscles, each with its own tendon running out to the foot, much like the human forearm contains a bundle of muscles with tendons running through the wrist to work the hand, and much like the human lower leg contains a bundle of muscles with tendons running through the ankle to work the foot. If you read my post on the hand, you will recall that the chicken foot contains numerous tendons running into it to pull the toes into different positions. The drumstick muscles are the engines that pull on these tendons and drive the foot.
Apparently, if you work carefully and pay close attention as you pull the muscles of the leg apart, you should be able to discover such minute things as veins, nerves, and synovial bursa. However, I haven’t had much luck finding these myself. (There are some tubes that are quite easy to notice, as they are filled with red blood. I believe these are veins, rather than arteries, because the arteries are muscular and contract upon death, squeezing the blood out of them, but I’m not positive about this.)
If you remove all muscle as much as you can down to the bone, you will find the skeleton of the chicken leg:
As with the resemblance of chicken wing to human arm, the resemblance of the chicken leg to the human leg is more than skin deep. The thigh contains a single large bone, which we may as well call the femur. The lower leg contains a pair of long bones, one of which is large and strong (the tibia), and the other of which is thin and frail and stuck to the first (the fibula). One difference is that in the human, the fibula is as long as the entire lower leg and is stuck to the tibia at both ends, whereas in the chicken, the fibula is so meager that it doesn’t even reach the ankle end. It is just a needle sticking down from the knee joint.
The resemblance continues if we examine the joints in more detail. The knee has a cartilagenous covering over the front, resembling a kneecap, and it has vertical ligaments on the sides of the knee and criss-cross ligaments inside that resemble the collateral and cruciate ligaments in a human knee. The hip is a ball-and-socket joint consisting of the rounded upper end of the femur fitting into a socket in the hip bone. Several ligaments hold the bones together, including a ligament within the socket uniting the head of the femur with the socket (the ligamentum teres).
Since chicken quarters are apparently normally produced by sawing the hipbone from the rest of the body, and since this cut apparently normally goes through the spine, a chicken quarter also gives a nice view of a longitudinal section of a spine.