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chapter 6 muscles
Question | Answer |
---|---|
the ability of skeletal muscle to shorten with force | contractility |
the capacity of skeletal muscle to respond to stimulus | excitability |
the ability to be stretched | extensibility |
ability to recoil to their original resting length after they have been stretched | elasticity |
surrounds deep muscle | epimysium |
separates muscle | fascia |
around the muscle | perimysium |
connective tissue sheath surrounding each fiber | endomysium |
made of microfilaments | myofilaments |
thin myofilaments | actin myofilaments |
thick myofilaments | myosin myofilaments |
highly ordered units made of actin and myosin | sarcomers |
when the outside of the cell is positively charged and the inside is negatively charged | resting membrane potential |
when the muscle cell is stimulated | action potential |
nerve cells that carry action potentials to skeletal muscle fibers | motor neurons |
the muscle that the branches that axons enter through | neuromuscular junction |
muscle near center of the cell | synapse |
a single motor neuron | motor unit |
enlarged nerve terminal | presynaptic |
space between the presynaptic terminal and muscle cell | postsynaptic terminal |
in the presynaptic terminal | synaptic vessels |
a neurotransmitter | acetylcholine |
releases the tension/contraction that acetylcholine prosuced | acetylcholinesterase |
the sliding of actin myofilaments past myosin myofilaments | sliding filament mechanism |
contraction of an entire muscle in response to a stimulus | muscle twitch |
the level a stimulus reaches when a muscle wont respond anymore | threshold or all-or-none response |
the time between a stimulus and motor neuron and the beginning of a contraction | lag phase |
time of contraction | contraction phase |
time which the muscle rests | relaxation phase |
when the muscle remains contracted without relaxing | tetany |
increase in the number of motor units being activated | recruitment |
needed for energy and muscle contraction | ATP |
what ATP degenerates too and is more stable | ADP |
ATP energy makes this | creatine phosphate |
exercise without oxygen | anaerobic respiration |
exercise with oxygen | aerobic respiration |
deep breath after exercising | oxygen debt |
length of the muscle does not change | isometric |
length of the muscle changes | isotonic |
constant tension produced by the muscles for long periods of time | muscle tone |
contract quickly and fatigue quickly | fast-twitch fibers |
contract more slowly and are more resistant to fatigue | slow-twitch fibers |
most stationary end of the muscle | origin |
end of the muscle undergoing the greatest movement | insertion |
muscle between the origin and insertion | belly |
muscles that move together to accomplish specific movements | synergists |
muscles that work in opposition to each other | antagonists |
if one muscle plays the major role in moving the rest | prime mover |
raises the eyebrows | occipitofrontalis |
closes the eyelids and causes "crow feet" wrinkles | orbicularis oculi |
flattens the cheeks | buccinator |
puckers the lips | orbiculris oris |
smiling muscle | zygomaticus |
sneering | levator labii superioris |
frowning | depressor anguli oris |
chewing | mastication |
4 pairs of mastication muscles | 2 pair of pterygoids, temporalis, masseter |
change the shape of the tongue | intrinsic tongue muscles |
move the tongue | extrinsic tongue muscles |
lateral neck muscles and prime mover, rotates and abducts the head | sternocleidomastoid |
group of muscles on each side of the back, responsible for keeping the back straight and the body erect | erector spinae |
muscles that move the thorax | thoracic muscles |