Chicken Dissection Analysis

Yellow: Pectoralis major
Blue: Pectoralis minor

The dissection we did the other day in class consisted of observing and comparing the muscles of a chicken with those of humans. The dissection started with the cleaning of the chicken by drying it and the next one was start to peel the skin. After this we open the chicken by the chest and we observe the different muscles that are in that zone, like the pectoralis major and minor. The pectoralis major goes from the keel through the shoulder to the humerus and it pull the wing vertically, and the pectoralis minor lifts the wing dorsally.

Blue: Trapezius
Yellow: Latissimus dorsi

In the upper back of the chicken we found two different main muscles: the trapezius and the latissimus dorsi. The trapezius run perpendicular from the backbone to the shoulder and pulls the shoulder back; in humans they are split into two parts. The latissimus dorsi runs from the spine into the armpit and extend or pull the wing.

Green: Biceps brachii
Blue: Deltoid
Yellow: Triceps humeralis

In the chicken first wing segment we found the biceps brachii that flexes the wing or arm, also the deltoid that is the muscle on the center of the top shoulder and helps to raise the upper arm, and lastly we found the triceps humeralis that extends the wing or arm; in humans this is a muscle used in doing reverse curls.

Green: Brachioradialis
Yellow: Flexor carpi ulnaris

The second wing segment is divided into brachioradialis that is the largest muscle on 

the superior side of the lower wing closest to 

the alula and it pulls the hand back, and also 

the flexor carpi ulnaris that is the largest muscle

 on the posterior side of the lower wing and 

it flexes the hand; in humans this is a primary muscle used in doing wrist curls.

Yellow= Sartorius
Blue= Quadriceps
Black= Iliotibialis
Red= Biceps Femoris
Green= Semitendinosus
White= Semimembranosus

In the chicken thigh we found a lot of different muscles. The sartorius that flexes the thigh and allows crossing of the legs. The iliotibialis is a group muscle that covers the whole lateral side of the thigh and extends it at the time that flexes the leg. The semimembranosus and the semitendinosus only extends the thigh. The quadriceps femoris lies on the inside of the thigh just medial to the sartorius in the bird, it's a group of 4 muscles which flexes the thigh and extends the lower leg. This muscles are used in doing leg extensions in humans.

Red= Gastrocnemius

Yellow= Tibialis anterior

Blue= Peroneus Longus

The chicken's drumstick is divided into the gastrocnemius, the peroneus longus and the tibialis anterior.

The gastrocnemius has two distinct heads in both birds and humans. It extends the foot and flexes the lower leg.

The peroneus longus helps to extend the foot.

The tibialis anterior is large and is directly under the peroneus longus in birds and flexes the foot.

All the muscles are differentiate between the insertion and origin because the intersection of the muscle moves but the origin not.