chapter 10 Flashcards
contractile elements of muscle fibers
myofibrils
bind to an active site on action
able to bend straighten during muscle contraction
ATPase enzyme breaks down ATP
properties of myosin heads
in relaxed muscles this is covering the active site on G actin
tropomyosin
attachment to G actin
attachment to tropomyosin
Binding of calcium
Troponin
globular subunits that form a long chain called F actin
G actin
strands twisted together to form and base structure
2F- Actins
specialized nerve cell that carries information from the brain and spinal cord to the muscles
motor neuron
point of communication between a motor neuron and its axon branches
synapse
end of an axon
presynaptic cleft
space between the presynaptic terminal and the muscle fiber
synaptic cleft
plasma membrane in the area of the junction
postsynaptic membrane
synaptic vesicles contain what Neurotransmitter
acetylcholine
During muscle contraction, myosin heads attach to thin filaments and pull them towards the M line, thin filaments slide inward Z discs become closer together, sarcomere shortens causing muscle fiber to shorten causing shortening of entire muscle
sliding filament theory
movement of myosin heads pulls the thin filaments past the thick filament towards the M line
power stroke
the attachment of myosin head to actin during contraction
cross-bridge