Chicken Dissection

During the chicken dissection lab, Nicole and Angela dissected the chicken by removing the chicken skin and internal organs. They slit the chicken medially and worked on dissecting different parts of the chicken. Meanwhile, Simrun and I identified the different muscles in the chicken, labeled them accordingly, and snapped pictures of the labels matching the muscles. 

There are many muscles involved in flexing and extending the leg. The semimembranosus and the semitendinosus, for example, are all involved in extending the thigh; the satorius and iliotibialis extend and flex the leg.

The origin is the immovable end of the muscle and insertion is the movable end of of the muscle. When a muscle contracts, the insertion is moved toward the origin. The iliotibialis, for example, is identified as the insertion because it extends the thigh and flexes the leg. 

Chicken muscles and humans are remarkably similar but also have apparent differences. 

• The gastrocnemius are both attached to the two organisms´ Achilles tendons; however, the Achilles tendon runs around the hock in the birds and the heel in humans. 
• Both the chicken and humans have latissimus dorsi that are directly distal to the trapeziuses of the two organisms´ back and extend or pull the wing for the chicken and arm for humans.
• The satorius runs down the front edge of the thigh from the ilium to the knee in birds but across the front of the thigh in humans.

Quadriceps Femoris: Muscle lying on the inside of the thigh just medial to the sartorius in the bird; Flexes the thigh and extends the lower leg

Gastrocnemius: Primary muscle of the dorsal and medial sides of the drumstick; Extends the foot and flexes the lower leg
Tibalis Anterior: Muscle larger than and directly under the peroneus longus in the birds; Causes pain in the disorder known as ¨shin splints¨ and flexes the foot
Peroneus Longus: Primary superficial muscle on the lateral side of the drumsticks in birds; Extends the foot

Brachioradialis: Largest muscle on the superior side of the lower wing closest to the alula; Pulls the hand back
Flexor Carpi Ulnaris: Largest muscle on the posterior side of the lower wing away from the alula; Flexes the hand

Semimembranosus: Muscle inferior and medial to the biceps femoris and extends the thigh
Biceps Femoris: Muscle lying just medial and inferior section of the iliotibials in the bird; primary upper leg muscle powering running and flexing the leg
Semitendinosus: Muscle anterior and medial to the semimebranosus on the inside of the thigh and extends the thigh

Sartorius: Muscle running down the front edge of the thigh from the ilium to knee in birds and flexes the thigh to allow the crossing of legs

Iliotibialis: Muscle that thrusts the knee back into hyperextension thereby locking the knee

Trapezius: Muscles running perpendicular from the backbone to the shoulder of the bird and pull the shoulder back
Latissimus Dorsi: Muscles directly distal to the trapeziuses on the bird´s and the human´s back that extend or pull the wing or arm

Pectoralis Major: Large superficial breast muscles of the bird that pull the wing ventrally, powering flight
Pectoralis Minor: Thin, triangular muscle situated under the pectoralis major that lifts the wing dorsally