Chapter 6: Microscopic Anatomy of Skeletal Muscle. Flashcards
Is skeletal muscle multinucleate?
Yes
Sarcolemma
Plasma membrane that covers groups of muscle fibers.
Myofibrils
Nearly fill the cytoplasm (Sarcolemma) and push aside nuclei. Long ribbon like organelles.
Sarcomeres
Made up of myofibrils which are chains of tiny contractile units.
Myofiliments
Structures that producer the banding pattern inside the sarcomere.
Myosin Filaments
Thick filaments made up of bundles of molecules of myosin protein. They also contain ATP enzymes. They extend the entire length of the dark band.
Cross bridges
Studded ends of myosin filaments that hold muscle together during contraction.
Actin
Also protein molecule that is thin, which is anchored to the Z disk.
Sarcoplasmic Reticulum
Interconnecting tubules and sacs that surround every myofibril.
What is the major role of the sarcoplasmic reticulum?
To store calcium and release it to give the final go signal to muscle for contraction.