Why did the chicken cross the road? To get to the dissecting tray!

For this lab we dissected a chicken to observe the various muscle groups and parts to see how they interact with each other. Muscles, bones, and tendons work together to facilitate the movement of the body. The tendon attaches muscle to bone and allows the muscle to work at its full capacity by withstanding the tensile strength and spring of the muscle when it contracts and elongates. 

An example of this is the supinator tendon that works to bend the forearm and rotate it, which is why its called the supinator tendon because it helps with supination. It also works with the biceps brachii muscles that works with other muscles to help with the supination process. 

The origin is where the tendon attaches to a generally immovable bone - some muscles have two or more of these that change their naming conventions - like the triceps and biceps in the arm. The insertion point is where the tendon attaches to a more movable bone. Because of this different in movement, the origin, which is generally stationary, contracts the muscles towards itself while the insertion point is more distal and moves when the muscles contracts. 

In chicken the pectoralis major and minor muscles are generally larger than in humans because chickens are generally bred - through artificial selection and some genetic modification - for their breast meat. They also have a larger tibialis posterior and anterior for the same reasons, artificial selection for a greater supply of chicken meat for consumption. A human's trapezius muscles is much more well defined than that of a chicken, because relative to their body mass, chicken's have a very small head so they do not need a large muscle to control and support it. Humans on the other hand, need large trapezius muscles to help keep the head supported and straight throughout the day. 

Below are pictures that we took during the lab: 

View of skinned chicken before dissection

Pectoralis Major: Movement of the shoulder joint
Pectoralis Minor:  Elevates/Depresses scapula and shoulders

Latissimus Dorsi: Extension, Adduction and Flexion of the shoulder joint
Trapezius: Move the scapula and support the arm/head

Iliotibialis: Extend, adduct, and rotate the hip/leg

Sartorius: Rotater and flexor of the hip joint.

Semitendinosus: Works with other muscles to extend the hip and flex the knee
Biceps femoris: Works for knee extension

Semimembranosus: Leg flexion and rotation, thigh extender

Quadriceps femoris: Powerful knee extenders

Gastrocnemius: Plantar flexing of foot at ankle joint and flexor of leg at knee joint
Tibialis anterior: Dorsiflexion and inversion of the ankle
Peroneus Longus: Evert and plantar flex the ankle

Brachioradialis: Strong elbow flexor
Flexor carpi ulnaris: Flexion and adduction of hand