Bio 221 lab 6 Muscles pt 1

fascicle

part of actual muscle - one ‘strand’

muscle fibers

cells, part of muscle fascicles

actin & myosin

two parts of muscle fibers, make up sarcomeres

myosin

thick filaments of sarcomere, makes up large part of a band, contracts, protein

actin

thin filament of sarcomere, moves closer to h band, protein

z line

create end of sarcomere.

a band

where most of the dark part of sarcomere, contains a lot of myosin

I band

light part of sarcomere, mostly actin

transverse tubule

between two terminal cisternae of sarcoplasmic reticulum

terminal cisternae

part of the edge of sarcoplasmic reticulum

triad

1 transverse tubule & two terminal cisternae

sarcoplasmic reticulum

network, contains ca2+ (ca2+ v. important to muscle contraction)

axon

send information to muscle fiber to make it move

motor unit

a motor neuron and all the muscle fibers it innervates

recruitment

the greater the movement, the greater the movement needed, the more muscle fibers that will be recruited

stimulation frequency (summation)

more action potentials are fired to generate more force