Alex's Anatomy and Physiology Education: Chicken Dissection Analysis

In this lab, we dissected a chicken to compare it's muscles anatomy and physiology to that of a human. We first had to remove the skin of the chicken using scissors, while carefully avoiding to cut any muscles. After removing the skin, we dissected the breast, back, arms, and legs of the chicken to observe their muscles' similarities and differences from humans. After careful cutting, we were able to observe certain muscles of the chicken similar to humans. The muscles purpose in organisms is to provide movement since it has the ability to contract and release, unlike other tissues. Muscles can also help provide maintenance of body structure and position. Bones also help serve this purpose too, as they assist in structuring our limbs and body's shape. Tendons are muscles connecting to bones, and are capable of withstanding external pressure. An example would be the supinator tendon, which helps bend the elbow and rotate the forearm. For the bone, we have our femur, which provides shape and structure to our legs. As for muscles, our hamstrings prove critical when it comes to our basic ability of walking. In each muscle, there are two ends that help it contract, the origin end and the insertion end. The origin of the muscle is a fixed attachment that cannot move, while the insertion end is able to move through contraction. When a muscle is contracted, the insertion end is moved towards the origin end. The insertion end usually runs along the muscle while the origin is at one end of the muscle.

Both the chicken and human have similar yet quite different muscle anatomy and physiology. The pectoralis major in chickens help them gain the ability to fly, while in humans it helps us bench press and do push ups. Biceps brachii in humans help us flex and bend our arm through the elbow. In chickens, the biceps brachii helps chickens bend and flex their wings to assist in flight and their basic nature. The trapezius in humans help move the scapulae and support the arm, along with providing posture. In chickens, the trapezius helps raise their wings while providing support for their posture.

The following are muscles that we observed and dissected:

Pectoralis major: supports wings during flight
Pectoralis minor: provides recovery position after flight
Trapezius: Supports back posture and helps raise wings
Latissimus Dorsi: runs from spine through side of back, helps move wings in multiple directions instead of one direction
Deltoid: helps raise wing and supports upper arm
Biceps Brachii: bends and flexes wings
Triceps humeralis: Supports lower wing, helps position wing into normal position
Flexor Carpi Ulnaris: Provides movement to hand and wrist
Brachiordialis: flexes forearm through elbow, responsible for supination and pronation
Sartorius: Important flexor and rotator of thigh through the hip joint
Iliotibialis: extends, abducts, and laterally rotate the hip
Biceps femoris: helps flex the knee
Semimembranosus: enables leg to flex and rotate, serves as a thigh extensor
Semitendinosus: helps medially rotate the femur and tibia when knee is extended
Quadriceps femoris: flexes the thigh and extends the leg, helps with leg extensions
Gastrocnemius: helps extend foot and flexes lower leg, primary muscle used for standing on your toes
Peroneous longus: primary superficial muscle on lateral side of drumstick, helps extend foot
Tibialis anterior: flexes the foot, causes the painful injury known as "shin splints"