Flashcards in ch 10 test Deck (43):
1
list the functions of muscle tissue
1. produce skeletal movement 2. maintain posture and body position 3. support soft tissues 4. guard entrances and exits 5. maintain body temperature 6. store nutrient reserves
2
epimysium
exterior collagen layer that is connected to deep fascia and seperates muscle from surrounding tissues
3
perimysium
surrounds muscle fiber bundles (fascicles) and contains the blood vessel and nerve supply to fascicles
4
endomysium
surrounds individual muscle cells, contains capillaries and nerve fibers contacting muscle cells as well as myosatellite cells (stem cells) that repair damage
5
fascicle
muscle fiber bundles
6
sarcolemma
the cell membrane of muscle cell that surrounds the sarcoplasm. A change in transmembrane potential begins contractions.
7
transverse tubules
transmit action potential through cell wh allows entire muscle fiber to contract simultaneously
8
triad
formed by 1 T tubule and 2 terminal cisternae
9
cisternae
concentrate calcium then release into sarcomeres to begin muscle contraction
10
myofibrils
lengthwise subdivisions w/n muscle fiber made up of myofilaments
11
myofilaments
bundles of protein filaments responsible for muscle contraction (thick and thin)
12
Thin filaments
made up of F-actin and nebulin with troponin and tropomyosin
13
actin
2 twisted rows of globular G-actin which have the active sites that bind w myosin
14
tropomyosin
a double strand that prevents actin-myosin interaction
15
troponin
a globular protein that binds tropomyosin to G-actin and is controlled by calcium
16
thick filament
contain myosin subunits and titin strands that recoil after stretching
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myosin
tail- binds to other myosin molecules
head- made of 2 globular protein subunits that reach for nearest thin filament forming cross bridges
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sarcomeres
contractile unit of muscles that form visable patterns within myofibrils (stripes)
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z-line
center of I band at the 2 ends of sarcomeres
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m-line
the center of the A band at the midline of sarcomere
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zone of overlap
where thick and thin filaments overlap
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titin
strands of protein that reach from tips of thick filaments to the z-line and stabilize the filaments
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sliding filament theory
thin filaments of sarcomere slide toward the m-line alongside thick filaments; width of A zone stays the same while Z lines move closer together
24
neuromuscular junction
special intercellular connectin between the nervous system and skeletal muscle fiber that controls calcium ion release into the sarcoplasm
25
stimulation sequence
1. stim from nerve 2. Ach released 3. binds to sites on muscle 4. action potential created by change in membrane voltage 5. all or nothing principle 6. sodium fromoutside muscle cell enters
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the contraction cycle
1. contraction cycle begins 2. active site exposure 3. cross-bridge formation 4. myosin head pivoting 5. cross bridge detachment 6. myosin reactivation
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roll of acteylcholine
neurotransmitter that changes the permeability to sodium ions
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roll of sodium
creates the action potential in the sarcolemma
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roll of calcium
binds w troponin to rotate tropomyosin and expose actin to myosin
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roll of ATP
breakdown creates energy
31
twitch
latent period followed by contraction phase then relaxation phase
32
treppe
increase in peak tension w ea successive stim delivered shortly after the completion of the relaxation phase of the preceding twitch
33
wave summation
successive stimuli arrive before the relaxation phase has been completed
34
incomplete tetanus
occurs if the stim frequency increases further, tension production rises to a peak and periods of relaxation are very brief
35
complete tetanus
stim frequency is so high that the relaxation phase is eliminated, tension plateaus at maximum levels
36
isotonic contraction
skeletal muscle changes length resulting in motion
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concentric contraction
isotonic contraction when the muscle shortens
tension>load (resistance)
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eccentric contraction
isotonic contraction when muscles lengthen
tension
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isometric contraction
skeletal muscle develops tension but is prevented from changing legnth
40
ATP energy
muscles store enough to start contraction then must create more as needed- aerobic metabolism of fatty acids in the mitochondria and/or anaerobic glycolysis in the cytoplasm
41
creatine phosphate
the storage molecule for excess ATP energy in resting muscles
42
glycolysis
primary energy source for peak muscular act.that produces 2 ATP per molecule of glucose an breaks down glocose from glycogen stored in skeletal muscles
43