Chicken Dissection Lab

In this dissection, my group and I found and took pictures of all the major muscles underlined in the lab packet we got in class. We also played around with the chicken by moving around the tendons and muscles and seeing how a part of the chicken moves. Muscles and bones work together in tandem meaning that the muscles attach to tendons and ligaments and the tendons and ligaments attach to bones. The muscles pull the bones, causing movement. The major difference when comparing the tendons of the insertion and the tendons of the origin is the flexibility and the amount of red blood nerve vessels found nearer to the origin than the insertion. In this lab, we examined several specific and major muscles to get a better sense of this.

A. Pectoralis major: This is the muscle that runs from the shoulder to the humerus. It pulls the wing ventrally  powering flight.

B. Pectoralis minor: This muscle is directly underneath and runs parallel to the pectoralis major. It lifts the wing dorsally, which is the recovery stroke of the wing in flight. In humans this muscle pulls the shoulder down and forward. 

A. Trapezius: These muscles run perpendicular from the backbone to the shoulder of the bird and pull the shoulder back. 

B. Latissimus dorsi: These muscles are directly distal to the trapeziuses on the bird's and the human's back. In both species they extend or pull the wing or arm.

A. Deltoid: This is the muscle on the center top of the shoulder and help to raise the upper arm or wing.

B. Biceps Branchii: This muscle is located near the uppxer part of the wing or arm. It flexes the wing or arm.

It is called "biceps" because it has 2 origins.

A. Triceps humeralis: This muscle is located in the inferior side of the upper arm or wing. It extends the wing or arm. It is called "triceps" because it has three origins.

A. Flexor carpi ulnaris: This is the largest muscle on the posterior side of the lower wing and it runs from the back of the elbow to the side of the "pinky finger" of humans. It flexes the hand.

B. Branchioradialis: This is the largest muscle on the superior side of the lower wing. It runs from the elbow to the thumb side of the hand. It pulls the hand back.

A. Sartorius: This muscle runs down the front edge of the thigh from the illium to the knee in birds. It flexes the thigh and allows for the crossing of the legs.

B. Iliotibialis, Gluteus maximus (humans): This muscle covers the whole lateral side of the thigh in birds and in humans it runs from the dorsal and lateral sides of the the pelvis to the lateral side of the knee. It extends the thigh and flexes the leg.

C. Biceps femoris: This muscle lies medial to the inferior section of the iliotibilalis. It flexes the leg.

D. Semimembranosus: This muscle is just inferior and medial to the thigh a bird. It extends the thigh.

E. Semitendinosus: This muscle is just anterior and medial to the semimembranosus of the inside of the thigh. It  also extends the thigh.

F. Quadriceps femoris (birds) Rectus femoris (humans): This muscle lies on the inside of the thigh just medial to the sartorius in the bird. It is a group of four muscles, hence its name "quadriceps," which make up the bulk of the front of the thigh in humans. It flexes the thigh and extends the lower leg. 

A. Gastrocnemius: This is the primary muscle of the dorsal and medial sides of the drumstick.  It extends the foot and flexes the lower leg.

B. Peroneus longus: This is the primary superfificial muscle on the lateral side of the drumstick in birds. It is smaller and runs up the lateral side of the lower leg in humans. 

C. Tibialis anterior: This muscle is larger than and directly under the Perneus longus in birds. In humans it runs along the lateral side of the shin bone (tibia) on the very front of the lower leg. It is the muscle that causes pain in the disorder known as "shin splints." It flexes the foot.