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Flashcards in Muscle Tissue Deck (61):
1

what is the function of muscle?

give movement, produce heat, gives shape, maintain posture, support other structures, regulate s organ volume

2

what is the name of muscle cells>

muscle fibers

3

what is epimysium?

surrounds entire muscle?

4

what are muscles a bundle of? surrounded by?

fascles, perimysium

5

within a fascle there are bundles of?

muscle fibers/muscle cells

6

what surrounds muscle fibers?

endomysium

7

what is the membrane of the muscle cell called?

sarcolemma

8

invagination of sarcolemma are called?

T tubules

9

sarcolemma is largely filled with?

myofibrils

10

what are glycogen?

energy storer of glucose

11

what are myoglobin?

oxygen

12

what stores Ca++?

sarcoplasmic reticulum

13

what are myofibrils?

sacs of sarcomers; used for contraction

14

what are sarcomers?

regions between z discs, filled with thick and thin myofilaments

15

which myofilament are thin?

I bands - light

16

which myofilament are thick?

A bands - dark

17

what types of muscle proteins are there?

contracting protein, regulatory protein and structural proten

18

what is contracting protein?

myosin, actin

19

what is regulatory protein?

troponin, ropomyosin

20

what is structural protein?

titin

21

what is thick filament?

myosin, held by m-line - doesnt move

22

what is thin filament?

actin, troponin, tropomyosin held by z disc

23

when muscle is relaxed what happens?

myosin binding sites on actin is covered by tropomyosin supported by troponin

24

what does titin protein do?

hold thick filament to z disc and m line

25

what is a neuromuscular junction?

where the nervous and muscle tissue meet

26

mechanism of contraction

Ap travels down axon of motor nerve, Ach leased, binds to receptors along sarcolemma, which causes Na+ channels to open and creating AP along sarcolemma through T tubules, which causes Ca++ to be leased from Sarcoplasmic Reticulum, which binds to troponin, which causes tropomyosin binding site to be exposed

27

contraction cycle

1. ATP attach to myosin - cock position - ADP + P 2. myosin head attached to actin - P released making bind stronger 3. ADP releases causing myosin to move back to original position, pulling thin filament towards m-line 4. ATP attached to myosin head, weakens bond, myosin detaches

28

relaxation of muscle

AChE breaks down ACh, CA++ channel closes, Ca++ pumped back into Sarcoplasmic Reticulum, no more action potential, no more exposed binding site

29

what are the 3 sources of ATP?

1. creatine phosphate 2. anaerobic cellular respiration 3. aerobic cellular respiration

30

what occurs in creatine phosphate?

ATP-ADP, phosphate to creatine=Creatine phosphate

31

how long does creatine phosphate source last?

15 seconds

32

what occurs in anaerobic cellular respiration?

glycolysis-> glucose splits into 2 pyruvic acid and 2 ATP, if no oxygen pyruvic acid turns into lactic acid, which diffuse into blood and burns

33

how long does anaerobic cellular respiration source last?

30-40 seconds

34

what occurs in the aerobic cellular respiration

2 pyruvic acid from anaerobic cellular respiration and make 36 ATP in mitochondria if oxygen is available

35

how long does the aerobic source last?

+30seconds, after 10 mins this is muscles 90% source of ATP

36

what is muscle fatigue?

inability to contract forcefully after prolonged activity

37

what is central fatigue

general feeling of tiredness

38

what is muscle fatigue due to?

lack of creatine, too little Ca++ in sarcoplasm, lack of oxygen, increase of lactic acid and ADP, not enough ACh from motor neuron

39

what is a motor unit?

10-15 to 3,000 muscle cells with one motor neuron

40

unified contraction amongst muscle cells from one motor unit is calleD?

unison

41

what is the average amount of cells to motor unit?

150

42

what is a twitch contraction

1 motor unit, with a brief contraction due to a single action potential

43

what is a myogram?

a graph of muscle contraction

44

how long does an action potential lasts?

1-2 msec

45

how long does a twitch contraction lasts?

20-200 msec

46

what are the periods of twitch contraction?

1. latent period 2. contraction period 3. relaxation period

47

what occurs during latent period?

lasts 2msec, tension in filaments but no shortening, Ca++ released from SR

48

what occurs in the contraction period?

lasts 10-100 msec, filaments slide closer to M-line

49

what occurs in relaxation period?

lasts 10-100 msec, Ca++ actively back to SR

50

what is wave summation?

after refractory period, before muscle can relax, muscle hit with stimulation again, second stimuli stronger

51

what is unfused tetanus?

continuous stimulation with little relaxation between each stimuli, lasts about 20-30 times per second

52

what is fused tetanus?

sustained stimuli with no relaxation between stimuli, lasts about 80-100 times per second

53

what is the graded response of muscles?

1. muscles fibers will contract maximally no matter if weak or strong signal 2.depends on how many muscle fibers stimulated or frequency of stimulation

54

what is significant about muscle tone?

most muscles are partially contracted all of the time, not enough to move but ready to contract important for maintaining posture and blood pressure

55

what types of whole muscle contraction are there?

isotonic and isometric

56

what is isotonic whole muscle contraction?

actually causing movement in your body, shortening muscle

57

what is isometric whole muscle contraction?

increasing muscle tension and force but no shortening on muscles

58

what is significant about cardiac muscles?

striated banches which allows interactions between fibers, less SR, more sarcoplasm and mitochondria, contraction lasts 10-15 times longer

59

what are the types of smooth muscle?

viscera and multiunit

60

what is significant about viscera?

1 motor neuron to one cell, gap junction allows for interaction with other muscle cells

61

what is significant about multiunit?

1 motor neuron with one cell, found in larger arteries, airways, arrector pili, iris, capillary body