BIO more muscles

DOMS- delayed onset muscle soreness
Motor neuron- a neuron that specializes in movement commands, they tell your muscles to contract, sends electricity to do so, attached to muscles & glands, command contraction
Motor units= motor neuron+muscle fibers it controls
Increase weight-> increase # of motor units activated
sacro= muscle
Fascicles- one bundle of muscle fibers, becomes tendon
Muscle fiber= muscle cell
Sarcoplasm- cytoplasm
Sarcoplasmic reticulum- endoplasmic reticulum
T tubules- deep invagination sarcolemma (piece of the plasma membrane) like the opposite of microvilli, like fork stabbed into plasma membrane, each tubes funnel electricity allowing your muscles to contract
Myofibril- chain of muscle cells (fibers), striated
Sarcomere- functional unit of a skeletal muscle, Z to Z line, muscle contraction-> sarcomere shortens
Myofilaments- proteins that make up sarcomere, made of myofibrils, actin & myosin
Myosin- thick filaments
Actin- thin filament
Cross bridge- when the myosin head attaches to the actin
Troponin- protein that attaches to the tropomyosin, has binding site for calcium
Tropomyosin- thin looking protein attached to actin, prevents myosin from attaching

5 steps to muscle contraction