Chicken Dissection

 On Thursday, we spent the class period dissecting a chicken carcass using a scalpel, a probe, and tweezers while labeling the various muscle structures and comparing the chicken's physical and functional differences to the human's. Because we went over the majority of the muscles previously in the lecture, it was easy to locate the general area of each muscle on the chicken's body.
 Muscles, bones, and tissues all play important functions in our bodies; for instance, our bones, which are composed of dense connective tissue, are responsible for supporting the body, protecting the body's soft organs, and forming blood cells. Tendons are flexible chords of fibrous tissue that is responsible for attaching a muscle to a bone.  For instance, the biceps are joined together by a tendon at the radius and ulna. Muscles are responsible for stabilizing joints, heat generation, maintaining the body's posture, and moving the body's bones and fluids.

 Overall, we noticed that the chicken had many functional similarities but had vastly different physical similarities. Because the chicken that we dissected was bred primarily for meat, we noticed that its body was extremely unbalanced and often toppled over, with parts of their bodies (e.g. the pectoralis minor and major) much larger in proportion than other parts of their body. On the other hand, most humans seem to have relatively proportional bodies. Another difference that we found was that the upper limbs of humans are arms while chickens possess wings as their upper limbs. While chickens and humans possess structural differences, both use their upper limbs for the same function. One similarity that we found between humans and chickens is that both possess epithelial, muscle, and connective tissue.

The pectoralis major is the breast muscle that runs from the shoulder to the humerus

The pectoralis minor lifts the wings dorsally which allows the chicken to recover when flying.

In chickens, the trapezius runs perpendicular 

from the backbone to the shoulder of the bird 

and is responsible for pulling the shoulders back.

In humans, the trapezius is split in 2 parts. 

The deltoid helps the raise the upper arm/wing.
The biceps is responsible for bending the arm/wing.
The triceps are responsible for straightening the arm/wing.

This is the chicken's largest muscle on the posterior side of the chicken's lower wing.
In humans, this muscle is responsible for flexing the hand.

This is the chicken's largest muscle on the superior side of the lower wing.
In humans,this muscle is responsible for pulling the hand back.

The sartorius is responsible for flexing the thighs and crossing the legs.

The iliubialis covers the lateral side of the chicken's thigh. In humans, it runs from the dorsal and lateral sides of the pelvis to the lateral side of the knee.

The biceps femoris lies medial to the inferior section of the iliotibialis and is responsible for flexing the leg.

The semimembranosus is inferior and medial to the biceps femoris and is responsible for extending the thigh.

The semitendinosus is anterior and medial to the semimembranosus and extends the thigh.

The quadriceps femoris lies on the inside of the thigh medial to the sartorius and is responsible for flexing the thigh and extending the lower leg. 

The gastrocnemius is the primary muscle of the drumstick. In both humans and chickens, the gastrocnemius is attached to the Achilles tendon/

Whole chicken before the dissection

An example of some of the chicken's tendons