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Muscular System
Question | Answer |
---|---|
the ability of muscle to shorten with force | contractibility |
the ability of a muscle to react to a stimulus | excitability |
the ability of a muscle to stretch | extensibility |
ability of a muscle to recoil to original length after stretching | elasticity |
connective tissue sheath directly on the muscle | epimysium |
connective tissue outside of epimysium that separates muscle | fascia |
muscle bundles | fasciculi |
bundles surrounded by this loose connective tissue | perimysium |
muscle cells | fibers |
connective tissue sheath around muscle fibers | endomysium |
a threadlike structure that extends along the fiber contained in the cytoplasm | myofibrils |
thin myofilaments | actin myofilaments |
thick myofilaments | myosin myofilaments |
basic structural and functional unit of muscle | sarcomeres |
myosin bands | A, H, M |
actin bands | Z, I |
charge difference in the membrane | membrane potential |
when muscle is stimulated and changes briefly | action potential |
nerve cells that carry stimulus to muscle | motor neurons |
axon branch that touches muscle | neuromuscular junction, synapse |
motor neuron and the muscle it stimulates | motor unit |
enlarged nerve terminal | presynaptic terminal |
space between presynaptic terminal and the muscle | synaptic cleft |
muscle fiber terminal | postsynaptic terminal |
contained in presynaptic terminal and secrete neurotransmitters | synaptic vesicles |
neurotransmitter that contracts muscle | acetylcholine |
enzyme that breaks down acetylcholine | acetylcholinesterase |
actin sliding on myosin myofilaments | sliding mechanism |
contraction of a muscle in response to a stimulus | muscle twitch |
stimulus level powerful enough to contract a muscle | threshold (all or none response) |
time between stimulus and action | lag phase |
time of contraction | contraction phase |
muscle stays contracted | tetany |
increase in motor units | recruitment |
high energy molecule | creatine phosphate |
without oxygen | anaerobic respiration |
with oxygen | aerobic respiration |
amount of oxygen needed in chemical reactions | oxygen debt |
ATP is used more in contraction than it can be produced | muscle fatigue |
length increase but tension does not | isotonic |
tension increase but length does not | isometric |
constant tension on a muscle | muscle tone |
contract and fatigue quickly | fast-twitch fibers |
contract and fatigue slowly | slow-twitch fibers |
stationary end of the muscle | origin |
end of the muscles moving the most | insertion |
between origin and insertion | belly |
muscles together to form one movement | synergists |
muscles working in opposition of each other | antagonists |
one major muscle in the role of movement | prime mover |
raises eyebrows | occipitofrontalis |
closes eyelids | orbicularis oculi |
puckers lips | orbicularis oris |
flattens cheeks | Buccinator |
smiling muscle | zyogomaticus |
frown | depressor anguli oris |
chewing | mastication |
move tongue, change shape | extrinsic, intrinsic |
lateral neck muscle | sternocleidomastoid |
group of muscles on the back | erector spinae |
quiet breathing | diaphragam |
tendinous area of abdominal wall | linea alba |
each side of the linea alba | rectus abdominis |
makes muscle looks segmented | tendinous inscriptions |
rotates scapula | trapezius |
pulls scapula anteriorly | serratus anterior |
flexes the arm | pectoralis major |
medially rotates and other movements of the arm | latissimus dorsi |
attaches humerus to the scapula and clavicle | deltoid |
extends forearm posterior | triceps brachii |
flexes forearm anterior | biceps brachii |
flexes forearm and supinates | brachialis/ brachioradialis |
holds th wrist for it doesn't bowstring | retinaculum |
flexes the wrist | flexor carpi |
extends writs | extensor carpi |
flexes fingers | flexor digitorum |
extends fingers | extensor digitoum |
buttocks | gluteus maximus |
extends the leg | quadriceps femoris |
flexes thigh | sartorius |
posterior thigh muscle | hamstring |
calf muscle | gastrocnemius and soleus |
flex foot and toes | Achilles tendon |