Chicken Dissection

In this lab, we dissected a chicken in order to learn about its muscles.  First, we turned it on its back and removed the skin so we could see its pectoralis major. We then cut the pectoralis major down the midline to expose the pectoralis minor.

We then turned the chicken over in order to see the trapezius, which pulls the shoulders back, and the latissimus dorsi, which extends the arm.

After that, we cut the skin off the wing in order to observe the deltoid, biceps brachii, and triceps humeralis.

Further down the wing, past the elbow joint, we saw the flexor carpi ulnaris and brachioradialis. 

We then moved on to the leg and the numerous muscles there, including the sartorius, iliotibialis, biceps femoris, semimembranosus, semitendonosus, and quadriceps femoris.

The final muscles we looked at were the gastrocnemius, peroneus longs, and tibialis anterior.

Muscle	Function (Chicken)	Function (Human)
Pectoralis Major	Pulls wing down	Adducts, flexes, and rotates arm
Pectoralis Minor	Pulls wing up	Abducts arm, depresses shoulder
Trapezius	Pulls shoulders back/shrugs shoulders	Extends head, elevates/depresses scapula, adducts arm
Latissimus Dorsi	Extends wing	Extends arm
Deltoid	Raises wing	Raises upper arm
Biceps Brachii	Flexes wing	Flexes elbow joint
Triceps Humeralis/Brachii	Straightens wing	Extends elbow joint
Flexor Carpi Ulnaris	Flexes hand & alula	Flexes/adducts hand
Brachioradialis	Pulls hand back	Flexes forearm at elbow, pronation/supination
Sartorius	Flexes thigh	Flexes thigh, allows legs to cross
Iliotibialis (birds) or Tensor Fasciae Latae, Gluteus Maximus, and Iliotibial Tract (humans)	Extends thigh, flexes leg	Extends thigh, flexes leg
Biceps Femoris	Flexes leg	Flexes leg
Semimembranosus	Extends thigh	Extends thigh
Semitendonosus	Extends thigh	Extends thigh
Quadriceps Femoris (birds) or Vastus Lateralis, Intermedius  and Medialis, and Rectus Femoris (humans)	Flexes thigh, extends lower leg	Flexes thigh, extends lower leg
Gastrocnemius	Extends foot, flexes lower leg	Extends foot, flexes lower leg
Peroneus Longus	Extends foot	Extends foot
Tibialis Anterior	Flexes foot	Flexes foot

The many similarities between major human and chicken muscles astonished me. There were a few small differences, but for the most part, chicken muscles perform very similar functions to  their human counterparts; most even share the same names. The muscles of chickens and humans also function in the same way; as the muscle contracts, the tendon of the insertion is moved toward the origin, flexing the joint.