Anatomy of a Muscle Fiber

background H G F E D C B A outline

Sarcoplasm

The cytoplasm of muscle fibers

Nuclei

Muscle fibers are multinucleated

Sarcolemma

Cell membrane of muscle fiber

T-tubule

Carries action potential to terminal cisterna

Sarcoplasmic Reticulum

Stores and
releases calcium

Terminal Cisterna

Expanded ends of SR

Myofibrils

Bundles of myofilaments
or contractile proteins

Mitochondria

Supply ATP
for muscle contraction

( ? )