Fascicles

What are fascicles?

Bundles of muscle fibers that can arrange themselves in a variety of ways to produce muscles in several shapes

Concentric rings

Forms circular muscles like the ones around the eyes and mouth

Convergent muscle

Spreads out but converges toward a tendon of insertion (a tendon is a strong fibrous connective tissue attaching to the bone like hamstring)

Fusiform

Tapers down to a tendon at two ends

Parallel Arrangement

Fascicles that run in a straight line parallel to the long axis of a muscle

Pennate

Muscles that are short and run at oblique angles

Unipennate

Muscle sits at one side of a tendon

Bipennate

Muscle sits on both sides, resembling a feather

Multipennate

Looks like several muscles inserted into the same tendon

Fascicles that run parallel

Shorten the most and sacrifice power

Fascicles that run oblique

shorten less and produce more power