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
when ACH is no longer released at the NMJ
Muscle relaxation
intermediate energy system, 15s short duration high intensity exercise
creatine phosphate
does not require oxygen 30-40s, involves breakdown of glucose moderate high intensity exercise
anaerobic
requires oxygen and break down of glucose enough energy for hours long term energy system period of rest or light to moderate exercise
aerobic
the inability of a muscle to maintain force of contraction after prolonged activity
muscle fatigue
the process in which the number of active motor units increase
motor unit recruitment
random stimulation of motor units creating isometric contraction for position and stability, balance
muscle tone
decrease in muscle tone
hypotonia
increase in muscle tone
hypertonia
change in muscle length force remains the same
isotonic
muscle shortens
concentric
muscle lengthens
eccentric
no change in length
isometric
slow twitch oxidative
type I
fast twitch oxidative
Type II a
fast twitch Glycolytic
Type II b
Type I
aerobic; muscles in back
Type II a
aerobic and anaerobic; Lower limbs
Type II b
anaerobic ; upper limbs
helps muscle contracts in unison
transports nutrients/extracellular fluid to inner parts of the muscle fiber
T-Tubules
movement of the body
maintenance of posture
respiration
production of body heat
contraction of organs and vessels
Functions of muscle tissue
contains mitochondria and synaptic vesicles
presynaptic terminal
alters activity of muscle fiber
acetylcholine
