Chapter 10 Flashcards

1
Q

Authorythmicity

A

Build in rhythm
Natural pacemaker of heart

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2
Q

Functions of muscular tissue

A

Producing movement
Stabilizing body positions
Storing/moving substances in body
Generating heat

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3
Q

Thermogenesis

A

Muscle tissue contracts producing heat

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4
Q

Electrical excitability

A

Ability to respond to stimuli by producing action potentials

Stimulated by electrical signals (auto rhythmic) or chemical stimuli (neurotransmitter/hormones/pH changes)

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5
Q

Muscle fibers also called

A

Myocytes

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6
Q

Subcutaneous layer/hypodermis

A

Aereolar/adipose separate in skin from muscle

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7
Q

Fascia

A

Dense sheet/broad band or ICT
Lines body wall, supports/surrounds muscles/organs

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8
Q

Layer of connective tissue extending from fascia

A

Epimysium
Perimysium
Endomysium

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9
Q

Epimysium

A

Outer later around entire muscle
DITC

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10
Q

Perimysium

A

DICT
Surrounds 10-100+ muscle fibers separating into fascicles

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11
Q

Fasicles

A

Bundles of 10-100+ muscle fibers
Can be seen with naked eye
Meat rips at these

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12
Q

Endomysium

A

Penetrates interior of each radicle and separating individual fibers

Mostly reticular fibers

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13
Q

Tendon

A

All three connective layers extend rope like from muscle and attach to periosteum

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14
Q

Aponeurosis

A

Tendon but Broad flat sheet

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15
Q

Neurons that stimulate skeletal muscle

A

Somatic motor neurons

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16
Q

Bloody supply of muscles

A

Capillaries

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17
Q

Sarcolemma

A

Llamas membrane of muscle cell

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18
Q

Transverse tubules

A

Invaginations of sarcolemma
Filled with interstitial fluid

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19
Q

How do muscle action potentials travel

A

Along sacrolemma through T tubules throughout muscle fiber

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20
Q

Sarcoplasm

A

Cytoplasm of muscle cell

Large amount of glycogen
Myoglobin

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21
Q

Myoglobin

A

Red protein only in muscle
Binds o2 and releases it for ATP production

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22
Q

Myofibrils

A

Tiny threads in sarcoplasm
Contractile organelles of skeletal muscle
2um diameter

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23
Q

Sarcoplasmic reticulum

A

Fluid filled membranous sacs encircling myofibril

Stores Ca2+

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24
Q

Terminal cisterns

A

Dilated end sacs of SR
Butt against t tubules

Releases Ca2+

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25
Q

Triad

A

T tubules and 2 terminal cisterns

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26
Q

Where are filaments found

A

In myofibrils

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27
Q

Thin filaments

A

Actin

8nm diameter

Contractile protein

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28
Q

Thick filaments

A

Myosin

16nm diameter

Contractile protein

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29
Q

Sarcomeres

A

Basic functional units of myofibril
Have filaments inside

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30
Q

Z disc

A

Seperate one sarcomere from bect

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31
Q

A band

A

Entire length of thick

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32
Q

Zone of overlap

A

Where thin/thick are
In A band

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33
Q

I band

A

Rest of thin filaments
Z disc in center

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34
Q

H zone

A

Thick not thin in A band

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35
Q

M line

A

Hold thick filaments at center of H zone

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36
Q

Contractile proteins

A

Myosin (thick)
Actin (thin)

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37
Q

Binding sites on myosin

A

Actin binding site
ATP binding site

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38
Q

Binding sites on actin

A

Myosin binding site

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39
Q

Regulatory proteins

A

Tropomyosin: blocks myosin binding sites in actin

Troponin: troponin moves tropomyosin away uncovering binding sites

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40
Q

Titan

A

Structural protein

Third most plentiful protein
Huge (50x larger than normal protein)

Z disc to M line stabilizing thick filament
Very elastic

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41
Q

Sliding filament mechanism

A

Thin slide inwards
I band and H zone narrow then disappear (max contraction)

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42
Q

What happens before Contraction cyle

A

SR release Ca ions into sarcoplams
Ca binds to troponin which moves tropomyosin away from binding sites

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43
Q

Contraction cycle steps

A

1.ATP hydrolysis: myosin head is energized and orientated (90°)

  1. Attachment of myosin to actin: cross bridge formed, P group released
  2. Power stroke: myosin head picots pulls thin past thick (45°), ADP released
  3. Detachment of myosin from actin: myosin binds ATP detaching cross bridge
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44
Q

cross bridges in thick filament

A

600
Attached/detaches 5/sec

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45
Q

Excitation contraction coupling

A

Sequence of events linking excitation (muscle action potential) to contraction (sliding of filaments)

Occurs at triad

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46
Q

Voltage gated Ca2+ channels

A

In t tubule membrane arrange as tetrads

Voltage sensors triggering opening of ca2+ release channels

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47
Q

Ca2+ release channels

A

Terminal cistern of SR

Prevent ca ions from leaving in relaxed, open during excitation for ca to flow into sarcoplasm and filaments

48
Q

Ca2+ -ATPase pumps

A

Terminal cisterns of SR

Use ATP to transport ca ions from sarcoplasm to SR

49
Q

Calsequestrin

A

Protein binds ca ion in SR to store them

50
Q

Length-tension relationship

A

100 percent max tension occurs when zone of overlap extend from edge of H zone to one end of thick filament

51
Q

When is there no overlap of filaments? What does this cause

A

170% stretched
No contraction as no cross bridge can be formed

52
Q

Neuromuscular junction

A

Synapse between somatic motor neuron and skeletal muscle fiber

Muscle action potential arise at NMJ

53
Q

Synapse

A

Region where communication occurs between two neurons

Between somatic motor neuron and muscle fiber at NMJ

54
Q

Synaptic cleft

A

Small gap at synapse

55
Q

Neurotransmitter

A

Chemical messenger from NmJ to muscle fiber

56
Q

Axon terminal

A

End of motor neuron divided into synaptic end bulbs

57
Q

Synaptic end bulbs

A

Contain membrane enclose sacs (synaptic vesicles)

58
Q

Synaptic vesicle

A

Membrane enclosed sacs in shanties end bulbs contains thousand of acetylcholine (ACh) modelcules (neurotransmitter)

59
Q

What is the neurotransmitter and NMJ

A

Acetylcholine (ACh)

60
Q

Motor end plate

A

Region of sarcolemma opposite synaptic end bulbs

Has ACh receptors

61
Q

Acetylcholine receptors

A

Integral membrane proteins that bind ACh at motor end plate

Have functional folds for large SA

Logan gated ion channels

62
Q

Muscle action potential steps

A
  1. Release of ACh: never impulse arrives, Ca ion stimulate synaptic vesicle to undergo Exocytosis of ACh
  2. Activation of ACh receptors: 2 ACh bind, opens ion channel for Na+ to flow
  3. Production of muscle action potential: inflow of Na tigers muscle action potential that goes along sarcolemma and into t tubules, SR release ca ion=contraction
  4. Termination of ACh activity: acetylcholinesterase (AChE) is an enzyme breaking down ACh
63
Q

Curare

A

Posion used by South American Indians
Causes muscle paralysis by burning and blocking ACh receptors

64
Q

Three ways muscle fibers produce ATP

A

Creatine phosphate
Anaerobic glycolysis
Aerobic respiration

65
Q

Creatine phosphate

A

Excess ATP synthesizes creatine phosphate is enzyme creatine kinase (CK) to transfer P group from ATP to creatine
CK transfer P group back to ADP=ATP when contraction begins

Very rapid, 15secs of energy

66
Q

Anaerobic glycolysis

A

Occurs in cytosol

Muscle glycogen->
glucose (from blood)->
Undergoes glycolysis=2ATP->
Pyruvic acid->
2 lactic acid->
Into blood

Faster than aerobic, 2 minutes of energy

67
Q

Aerobic respiration

A

Pyruvic acid from glycolysis enter mitochondria

Fatty acids from adipose cells, Pyruvic acid from glycolysis, O2 from hemoglobin/myoglobin, amino acids from protein breakdown all enter Krebs cycle and electron transport chain in mitochondrion

Produces heat, Co2, O2, H2O, 30-32ATP
Several minutes to hours of energy

68
Q

Where does muscular tissue get O2 from?

A
  1. Oxygen that diffuses into muscle fibers from blood (hemoglobin)
  2. Oxygen release by myoglobin within muscle fibers
69
Q

Muscle fatigue def

A

Inability of muscle to maintain force of contraction after prolonged activity

70
Q

Central fatigue

A

Feeling of tiredness/desire to stop

Cause by changes in central nervous system thought to be protective mechanism

71
Q

Oxygen debt

A

Added oxygen above resting oxygen consumption, taken in after exercise

Recovery period few minutes to several hours

72
Q

How does extra oxygen during oxygen debt restore resting metabolic conditions? (3)

A

Convert lactic acid back into glycogen stores in liver

Resynthesize creatine phosphate and ATP in muscle fibers

Replace oxygen removed from myoglobin

73
Q

Recovery oxygen uptake

A

Elevated body temp increase texted it reactions=more ATP needed=more O2 needed
Heart works harder=more ATP
Tissue repair is increased=more ATP

74
Q

Motor unit

A

Consists of somatic motor neuron plus all skeletal MF it stimulates

Average of 150 MF

75
Q

Twitch contraction

A

Brief contraction of all MF in a motor unit in response to single action potential in motor neuron

20-200 m sec

76
Q

Myogram

A

Record of muscle contraction

77
Q

Latent period

A

Delay of contraction

Muscle action potential sweeps over sarcolemma, ca ion release from SR

2msec

78
Q

Contraction period

A

Ca ion binds to troponin, tropomysion exposes binding sites, cross bridges form

10-100 msec

79
Q

Relaxation period

A

Ca ions actively transports back into SR, cross bridges detach

10-100 msec

80
Q

Refractory period

A

Period of lost excitability

Skeletal: 1msec
Cardiac: 250msec

81
Q

Wave summation

A

Stimuli arriving at different times cause larger contractions

Infused tetanus
Fused tetanus

82
Q

Infused tetanus

A

20-30x/sec

Partially relaxes=wavering contraction

83
Q

Fused tetanus

A

80-100x/sec

Doesn’t relax at all, cant see individual twitches

84
Q

Motor unit recruitment

A

Process in which number of active motor units increases

Some contract other relaxes=delays muscle fatigue

Weakest recruited first

85
Q

Muscle tone

A

Small amount of tautness/tension due to weak involuntary contraction of motor units

86
Q

Flaccid

A

State of limpness in which muscle tone is lost

87
Q

Isotonic contraction

A

Concentric isotonic contraction: muscle shortens/moves

Eccentric isotonic contraction: muscle lengthens/moves

88
Q

Isometric contraction

A

Tension generated isn’t large enough to move muscle length doesn’t change

89
Q

Red muscle fibers vs white

A

High myoglobin, mitochondrion, capillaries

Low myoglobin

90
Q

Slow oxidative fibers

Myoglobin content
Mitochondria
Capillaries
Colour

A

Large
Many
Many
Red

91
Q

Fast oxidative glycolytic fibers

Myoglobin content
Mitochondria
Capillaries
Colour

A

Large
Many
Many
Red-pink

92
Q

Fast glycolytic fibers

Myoglobin content
Mitochondria
Capillaries
Colour

A

Small
Few
Few
White

93
Q

SO Fibers

Capacity ATP generation/method
Rate of ATP hydrolysis
Contraction velocity
Fatigue resistance
Creatine kinase
Glycogen stores
Order of recruitment
Location where abundant
Primary function

A

High by aerobic respiration
Slow
Slow
High
Lowest
Low
First
Postural muscles
Maintaining posture/endurance

94
Q

Fog Fibers

Capacity ATP generation/method
Rate of ATP hydrolysis
Contraction velocity
Fatigue resistance
Creatine kinase
Glycogen stores
Order of recruitment
Location where abundant
Primary function

A

Intermediate aerobic and anerobic glycolysis
Fast
Fast
Intermediate
Intermediate
Intermediate
Second
Lower limb
Walking/sprinting

95
Q

FG fibers

Capacity ATP generation/method
Rate of ATP hydrolysis
Contraction velocity
Fatigue resistance
Creatine kinase
Glycogen stores
Order of recruitment
Location where abundant
Primary function

A

Low anerobic
Fast
Fast
Low
Highest
High
Third
Extraocular muscles
Rapid intense/short duration

96
Q

Microscopic appearance of three muscular tissues

A

Skeletal: long, peripheral nuclei, unbranched, straited

Cardiac: branch, central nucleus, intercalated discs, striated

Smooth: thick middle tapered ends, central nucleus, not striated

97
Q

Location of three MT

A

Skeletal: attached to bones by tendons
Cardiac: heart
Smooth: walls of hollow viscera, airways, BV, iris, cilia, arrector pili

98
Q

fiber diameter/length of 3 MT

A

Skeletal: very large (10-100um)
Very large (100um-30cm)
Cardiac: large (10-20um)
Large(50-100um)
Smooth: small (3-8um)
Intermediate (30-200um)

99
Q

Connective tissue comments of 3 MF

A

Skeletal: Endomysium Perimysium Epimysium
Cardiac: Endomysium and Perimysium
Smooth: Endomysium

100
Q

Contractile proteins organized in sarcomere of three MT

A

Skeletal: yes
Cardiac: yes
Smooth: no

101
Q

SR in three MT

A

Sketela: abundant
Cardiac: some
Smooth: very little

102
Q

T Tubules in three MT

A

Skeletal: yes A-I band junction
Cardiac: yes with z disc
Smooth: no

103
Q

Junctions between fibers of three MT

A

Skeletal: none
Cardiac: intercalated discs
Smooth: gap in visceral smooth, none in multi unit smooth

104
Q

Autorhythmicity in three MT

A

Skeletal: no
Cardiac: yes
Smooth: yes in visceral

105
Q

Source of ca ions for contraction in three Mt

A

Sketal: SR
Cardiac: SR/ interstitial fluid
Smooth: SE/interstitial fluid

106
Q

Regulatory proteins for contraction I three MT

A

Skeletal: troponin and tropomyosin
Cardiac: ^
Smooth: calmodulin/myosin light chain kinase

107
Q

Speed of contraction of three MT

A

Skeletal: Fast
Cardiac:Moderate
Smooth:slow

108
Q

Nervous control of three MT

A

Skeletal: voluntary (somatic)
Cardiac: involuntary (autonomic)
Smooth: ^

109
Q

Contraction regulation of three MT

A

Skeletal: ACh released by somatic motor neurons

Cardiac: ACh/norepinephrine released by autonomic motor neurons, hormones

Smooth: ^ as well as local chemical changes, stretching

110
Q

Capacity for regeneration of three MT

A

Skeletal: limited via satellite cells
Cardiac: limited under certain conditions
Smooth: considerable via pericytes

111
Q

Hypertrophy

A

Enlargement of existing cells

112
Q

Hyperplasia

A

Increase in number of fibers

113
Q

Visceral smooth muscle tissue

A

Skin walls of small arteries/veins/hollow organs

Contract in unison

114
Q

Multi unit smooth muscle tissue

A

Walls of large arteries/airways/arrector pili/iris/cilia

Only one MF contracts

115
Q

What does smooth have instead of T tubules

A

Caveolae: small invaginations of plasma membrane

116
Q

Calmodulin

A

Regularity protein of smooth MT

Binds ca ion, activates myosin light chain kinase=adds P to myosin head