Understanding Muscle Structure

Front

Muscle Structure

Back

Composed of muscle fibers, connective tissue, blood vessels, and nerves

Front

Fascicle

Back

Bundle of muscle fibers

Front

Endomysium

Back

Connective tissue surrounding individual muscle fibers

Front

Sarcomere

Back

Basic contractile unit of muscle fiber

Front

Myofibril

Back

Rod-like unit within muscle cells

Front

Actin

Back

Thin filament protein in sarcomere

Front

Myosin

Back

Thick filament protein in sarcomere

Front

Z-line

Back

Boundary of a sarcomere

Front

M-line

Back

Center of sarcomere, holds myosin filaments

Front

A-band

Back

Dark area; extends length of myosin filaments