skeletal muscle fibers

sarcoplasmic reticulum

specialized smooth endoplasmic reticulum, which stores, releases, and retrieves Ca+2

T tubules

projection of the sarcolemma into the interior of the cell

sarcolemma

plasma membrane of a skeletal muscle fiber

mitochondria

converts nutrients unto the ATP, which stores energy

epimysium

outer layer of connective tissue around skeletal muscle

endomysium

loose, and well hydrated connective tissue covering each muscle fiber in a skeletal muscle

sarcomere

longitudinally, repeating functional unit of skeletal muscle, with all contractile and associated proteins involved in contraction

perimysium

connective tissue that bundles skeletal muscle fibers into fascicles within a skeletal muscle

myofibril

long, cylindrical organelle that runs parallel within the muscle fiber and contains the sarcomeres

myofilaments

key molecular regulators of the contraction

fascicle

bundle of muscle fibers within a skeletal muscle

A band

location where myofilament movement occurs during a muscle contraction