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76 Cards in this Set
- Front
- Back
three basic types of muscle |
skeletal muscle cardiac muscle smooth muscle |
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what types of muscle are elongated |
skeletal and smooth |
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what is a muscle fiber |
muscle cell |
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what makes muscles contract |
movement of microfilaments |
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myo and mys refers to? |
muscle |
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sarco refers to? |
flesh |
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skeletal muscle characteristics |
attached by tendons to bones multinucleate striated voluntary |
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what are skeletal muscle cells surrounded by? |
connective tissue |
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layers of connective tissue wrappings |
endomysium perimysium epimysium fascia |
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encloses a single muscle fiber |
endomysium |
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wraps around a fascicle (bundle) of muscle fibers |
perimysium |
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covers the entire skeletal muscle |
epimysium |
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on the outside of the epimysium |
fascia |
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what are tendons, what are they made of, and where do you find them |
cord like structures mostly collagen fibers often cross a joint due to toughness and small size |
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what are apeneuroses and what do they do |
sheet like structures attach muscles indirectly to bones, cartilages, or connective tissue coverings |
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what are the sites of muscle attachment |
bones cartilage connective tissue coverings |
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smooth muscle characteristics +location |
no striations spindle shaped cells single nucleus involuntary found mainly in the walls of hollow organs
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cardiac muscle characteristics +location |
striations usually single nucleus branching cells joined to another muscle at an intercalated disc involuntary found in the heart |
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skeletal muscle functions |
produce movement maintain posture stabilize joints generate heat |
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specialized plasma membrane |
sarcolemma |
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what is the H zone? |
bare zone that lacks actin filaments |
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what does the sarcoplasmic reticulum do and where is it located? |
stores and releases calcium surrounds the myofibril |
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ability to receive and respond to a stimulus |
excitability (responsiveness of irritability) |
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ability to shorten when an adequate stimulus is received |
contractility |
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ability of muscle cells to be stretched |
extensibility |
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ability to recoil and resume resting length after stretching |
elasticity |
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what stimulates skeletal muscles |
motor neuron (nerve cell) |
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one motor neuron and all the skeletal muscle cells stimulated by that neuron |
motor unit |
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association site of axon terminal of the motor neuron and muscle |
neuromuscular joint |
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gap between nerve and muscle |
synaptic cleft |
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long organelles inside muscle cell |
myofibrils |
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what is between nerve and muscle |
synaptic cleft and interstitial fluid |
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chemical released by nerve upon arrival of nerve impulse |
neurotransmitter |
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what is the neurotransmitter for skeletal muscle |
acetylcholine (ACh) |
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how does nerve impulse transmit to muscle |
acetylcholine attaches to receptors on the sarcolemma sarcolemma becomes permeable to sodium sodium rushed into the cell generating an action potential once started, it cannot he stopped |
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what is the sliding filament theory |
activation by nerve causes myosin heads to attach to binding sites on the thin filament pulling them towards the center of the sarcomere causing a sliding of the myosin along the actin |
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muscle fiber contraction is? |
all or none |
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are all fibers stimulated during an interval? |
no, but different combinations can give off different responses |
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graded responses can be produced by changing? |
frequency of muscle stimulation number of muscle cells being stimulated |
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what is a twitch? |
single, brief contraction not normal |
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what is tetanus? |
summing of contractions one is immediately followed by another does not completely return to resting state effects are added |
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specialized smooth ER |
sarcoplasmic reticulum |
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types of tetanus? |
unfused or incomplete tetanus fused or complete tetanus |
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unfused tetanus characteristics |
some relaxation occurs between contractions results are summed |
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fused tetanus characteristics |
no evidence of relaxation before the following contractions result is a sustained muscle contraction |
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what does muscle force depend on |
number of fibers stimulated |
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what does more fibers contracting mean? |
greater muscle tension |
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when do muscles stop contracting |
when they run out of energy |
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where do muscles get their energy, how does it release, and how long is it worth |
stored ATP bond (third phosphate group) is broken to release it 4-6 seconds |
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after using ATP for muscle contraction, what’s next? |
direct phosphorylation of ADP by creative phosphate (CP) |
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what is CP, where is it found, what does it do, how long does it last |
creative phosphate muscles cells transfers energy to regenerate ATP around 15 seconds |
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glucose is broken down to carbon dioxide and water, releasing energy |
Aerobic respiration, requires continuous oxygen, slow |
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why are myofibrils aligned |
to give distinct bands |
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reaction that breaks down glucose |
anaerobic respiration, requires no oxygen |
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I Band |
light band contains only thin filaments |
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A Band |
dark band contains the entire length of the thick filaments |
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contractile unit of a muscle fiber |
sarcomere |
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types of myofilaments? |
thick (myosin) filaments thin (actin) filaments |
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thick filament characteristics |
also called myosin composed of the protein myosin has ATPase enzymes have heads (extensions or cross bridges) |
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thin filament characteristics |
also called actin composed of the protein actin anchored to the Z disc |
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where do the pathways form in aerobic respiration |
mitochondria |
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glucose is broken down to pyruvic acid to produce some ATP, then converts to lactic acid |
lactic acid formation, fast |
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lactic acid produces? |
muscle fatigue |
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what happens when a muscle is fatigued |
it is unable to contract even with a stimulus
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what is common cause for muscle fatigue and how do you fix it |
oxen debt gets rid of accumulated lactic acid |
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what causes the muscle to contract less |
acidity and lack of ATP |
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myofilaments are able to slide past each other, muscle shortens, movement occurs |
isotonic contractions |
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tension in the muscle increase, is unable to shorten to produce movement |
isometric contractions |
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what is muscle tone |
when some fibers are contracted even in a released muscle |
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the process of stimulating various fibers of muscle tone is |
involuntary |
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exercise does what to muscles |
increases size, strength, and endurance |
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what does aerobic exercise do |
stronger more flexible muscles with greater resistance to fatigue metabolism more efficient improves digestion and coordination |
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movement is attained due to a muscle moving an |
attached bone |
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muscles are attached the the |
origin and insertion |
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attachment to a moveable bone |
origin |
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attachment to an immovable bone |
insertion |