Chp10- Muscle Tissues Flashcards Preview

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Flashcards in Chp10- Muscle Tissues Deck (171)
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1
Q

What is a primary tissue type?

A

• muscle tissue

2
Q

What are the 3 divisions of a muscle tissue?

A
  1. Skeletal muscle tissue
  2. Cardiac muscle tissue
  3. Smooth muscle tissue
3
Q

What does skeletal muscle tissue do?

A
  • attaches tithe skeletal system

* allows us to move

4
Q

What are the 6 functions of skeletal muscle tissue?

A
  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
5
Q

What are the components of skeletal muscle?

A
  1. Muscle tissue (connective cells/fiber)
  2. Connective tissue
  3. Nerves
  4. Blood vessels
6
Q

What are the 3 layers of connective tissue?

A
  • Epimysium
  • Perimysium
  • Endomysium
7
Q

What is the Epimysium?

A

• exterior collagen layer

8
Q

What is the Epimysium connected to?

A

• deep fascia

9
Q

What does the Epimysium do?

A

• separates muscle from surrounding tissues

10
Q

What is the Perimysium?

A

• fibrous connective tissue

11
Q

What is the Perimysium rich in??

A

• rich is collagen and elastin

12
Q

What does the Perimysium surround?

A

• muscle fiber bundles (fascicles)

13
Q

What does the Perimysium contain?

A

• blood vessels and nerve supply for the fascicles

14
Q

What is the Endomysium?

A

• delicates connective tissue layer

15
Q

What does the Endomysium surround?

A

• individual muscle cells/fiber

16
Q

What does the Endomysium contain?

A
  • capillaries and nerve fibers contacting muscle cells

* myosatellite cells (stem cells)

17
Q

What is another name for myosatellite cells?

A

•Stem cells

18
Q

What does myosatellite cells do?

A

• repair damage

19
Q

What happens when the Epimysium, the Perimysium and Endomysium come together??

A

• form connective tissue attachment

20
Q

To what does the connective tissue attach to?

A

• bone matrix

21
Q

What is the connective tissue called?

A
  • tendon bundle

* aponeurosis sheet

22
Q

What does muscles have ?

A

• extensive vascular systems

23
Q

What does this vascular system supply to the muscle??

A
  • oxygen
  • nutrients
  • carry away waste
24
Q

How are the voluntary skeletal muscles controlled?

A
  • nerves of the central nervous system

* brain and spinal chord

25
Q

How do skeletal muscle cells develop?

A

• through the fusion of embryonic cells

26
Q

How are the embryonic cells called?

A

• myoblast

27
Q

How long can skeletal muscle cells be?

A
  • 30 cm

* 12 inch

28
Q

What does skeletal muscle cells contains?

A

• hundreds of nuclei

29
Q

What is the sarcolemma?

A

• cell membrane of a muscle cell (fiber)

30
Q

What does the sarcolemma surround?

A

• the sarcoplasm

31
Q

What is the sarcoplasm?

A

• cytoplasm of a muscle cell

32
Q

What begins contraction of a muscle?

A

• change in the transmembrane potential

33
Q

What are the transverse tubules??

A

• narrow tubes that are continuous with the sarcolemma

34
Q

What is another name for transverse tubules??

A

• T tubules

35
Q

What do the T tubules do??

A
  • transmit action potential through cell

* allow entire muscle to contract simultaneously

36
Q

What are the properties of T tubules?

A

• same as sarcolemma

37
Q

What ate myofibrils??

A

• lengthwise subdivision w/in muscle fibers

38
Q

What makes up myofibrils?

A

• bundles of protein filaments

39
Q

What are the protein filaments called??

A

• myofilaments

40
Q

What are myofilaments responsible for?

A

• muscle contraction

41
Q

What are the types of myofilaments?

A
  • thin filaments

* thick filaments

42
Q

What are thin filaments made up of?

A

• protein actin

43
Q

What are thick filaments made up of?

A

• protein myosin

44
Q

What is the sarcoplasm if reticulum (SR)?

A

• membranous structure surrounding each myofibril

45
Q

What is the structure of Sarcoplasmic Reticulum?

A

• similar to Smooth ER

46
Q

What does the sarcoplasmic reticulum do?

A

• forms chambers attached to T tubules

47
Q

What are the chambers formed by sarcoplasmic reticulum called?

A

• terminal cisternae

48
Q

What is a TRIAD composed of?

A
  • 1 T tubule

* 2 terminal cisternae

49
Q

What does ciaternae concentrate??

A

• Ca2+ via ion pumps

50
Q

Where does the cisternae release the Ca2+?

A

• onto sarcomeres

51
Q

Why does the cisternae release the Ca2+?

A

• to begin muscle contraction

52
Q

What are sarcomeres??

A

• contractile units of muscles

53
Q

How are myofibrils built??

A

• by 10k sarcomeres attached end to end

54
Q

What do these sarcomeres form?

A
  • visible patterns (stripes) w/in myofibrils
  • dark thick filaments
  • light thin filaments
55
Q

What are the thick filaments called?

A

• A bands

56
Q

What are the thin filaments called??

A

• I bands

57
Q

Where do thick and thin filaments over lap??

A

• in the zone of overlap

58
Q

Where does the M line occur?

A

• the Middle

59
Q

What does the Z line mark?

A

• boundary between adjacent sarcomeres

60
Q

What are thin filaments made up of?

A
  • F-acting filamentous
  • nebulin
  • tropomyosin
  • troponin
61
Q

What is F-acting (filamentous)?

A

• 2 twisted rows of globular G-acting

62
Q

What does the active (yellow) actin site do?

A

• Bind to myosin

63
Q

What does Nebulin do?

A

• holds F-acting strands together

64
Q

What does Tropomyosin do?

A

• prevents actin-myosin interaction

65
Q

What does Troponin do?

A

• binds tropomyosin to actin

66
Q

How is troponin controlled?

A

• by Ca2+

67
Q

What does the thick filaments contain?

A
  • about 300 twisted myosin subunits

* titin

68
Q

What does Titin do?

A

• recoil after stretching

69
Q

That does the tail of the myosin molecule do?

A

• binds to other myosin molecules

70
Q

What does the head of myosin molecule do?

A

• teaches the nearest thin filament

71
Q

What is the head of the myosin made up of?

A

• 2 globular protein subunits

72
Q

What happens during contraction to myosin head?

A
  • interact w/ actin filaments
  • for cross-bridges
  • pivot
73
Q

How is contraction initiated?

A
  1. Ca2+ binds troponin molecule
  2. Troponin-tropomyosin complex changes shape
  3. Exposes active site of F-actin
74
Q

What happens to thin filaments in filament theory?

A

• slide towards M line

75
Q

What happens to the dark area of thick filaments in sliding filament theory??

A

• the width of A zone stays the same

76
Q

What happens to the end of sarcomeres in sliding filament theory??

A

• Z line moves closer together

77
Q

What does the process of contraction involve?

A
  1. Neural stimulation of sarcolemma
  2. Muscle fiber contraction
  3. Tension production
78
Q

What happens in neural stimulation if sarcolemma?

A

• causes excitation-contraction coupling

79
Q

What happens in over contraction??

A

• interaction of thick and thin filaments

80
Q

What is the Neuromuscular Junction?

A
  • NMJ

* special intercellular connection between the. Record system and a skeletal muscle fiber

81
Q

What does the neuromuscular junction control?

A

• calcium ion release into the sarcoplasm

82
Q

What is the synaptic cleft?

A

• narrow space that separates the axon terminal of the neuron from the opposing motor end plate

83
Q

Step 1 of neuromuscular junction.

A

• cytoplasm of axon contains vesicles filled w: molecules of acetylcholine

84
Q

What is acetylcholine? Stp1

A

• a neurotransmitter

85
Q

What is a neurotransmitter? Stp1

A

• chemical released by a neuron to change the permeability or other properties of the cell’s plasma membrane

86
Q

What is an action potential? Step2

A

• sudden change in the membrane potential that travels along the length of axon

87
Q

What happens when the action potential reaches the neuron’s axon terminal? Step3

A

• change in the permeability triggers the exocytosis of ACh into the synaptic cleft

88
Q

When does exocytosis occur? Stp3

A

• as vesicles fuse with the neuron’s plasma membrane

89
Q

What is the 1st step of contraction cycle?

A
  1. Contraction cycle begins

• arrival of Ca2+

90
Q

What is the 2nd step of contraction cycle?

A
  1. Active-site exposure
91
Q

What is the 3rd step of contraction cycle?

A
  1. Cross-bridge formation
92
Q

What is the 4th step of contraction cycle?

A
  1. Myosin head pivoting
93
Q

What is the 5th step of contraction cycle?

A

• Cross-bridge detachment

94
Q

What is the 6th step of contraction cycle?

A
  1. Myosin reactivation
95
Q

How is tension produced?

A
  • sarcomeres shorten

* muscle pulls together

96
Q

Where can muscle shortening occur?

A
  • both ends of muscle

* one end of muscle

97
Q

What determines where the shortening happens?

A

• the way the muscle is attached at the ends

98
Q

What does contraction duration depend on?

A
  • neural stimulus
  • number of free calcium ions in sarcoplasm
  • availability of ATP
99
Q

What happens when the muscle relaxes.

A
  • Ca2+ concentration falls
  • Ca2+ detached from troponin
  • active sites are recovered by tropomyosin
100
Q

Is contraction an active process?

A

• yes

101
Q

What does SR release?

A

• Ca2+

102
Q

What triggers contraction?

A

• Ca2+ in the sarcoplasm

103
Q

What happens as thin filaments slide between thick filaments?

A

• skeletal muscle shortens

104
Q

Is relaxation an active or passive process??

A

• passive

105
Q

What does tension production depends on?

A
  • number of pivoting cross-bridges
  • fibers resting length at time of stimulation
  • frequency of neural stimulation
106
Q

What does a single. Rural stimulation produce?

A

• single contraction or twitch

107
Q

How long does a single twitch last?

A

• 7-100 milliseconds

108
Q

What does sustain muscular contraction require?

A

• many stimuli

109
Q

What are the 3 stages of a twitch?

A
  1. latent period
  2. Contraction phase
  3. Relaxation phase
110
Q

How long does latent period last?

A

• 2 msec

111
Q

How long does contraction phase last

A

• 15 Msec

112
Q

How long does relaxation phase last?

A

• 25 msec

113
Q

What is a treppe?

A
  • stair-step increase in twitch tension

* < 50/sec

114
Q

What is same summation?

A
  • increasing tension or summation of twitches
  • repeated stimulation before end of relaxation
  • > 50/ sec
115
Q

What is Incomplete tetanus

A

• when rapid stimulus continues and muscle is not allowed to relax

116
Q

What is complete tetanus?

A
  • strings frequency is high enough

* relaxation phase is completely eliminated

117
Q

What does motor units contain?

A

• 100s of muscle fibers that contract at the same time

118
Q

What is isotonic contraction?

A

• skeletal muscle changes length

119
Q

What are the 2 types of isotonic contraction?

A
  • Concentric

* Eccentric

120
Q

What is concentric contraction?

A
  • muscle shortens

* tension is greater than load

121
Q

What is eccentric contraction?

A
  • muscle lengthens

* muscle tension is lesser than load

122
Q

What is isometric contraction?

A
  • skeletal muscle does not change in length

* still develops tension

123
Q

What happens when as the heavier the load?

A
  • longer time for shortening to begin

* less muscle will shorten

124
Q

What is creating phosphate?

A

• storage molecule for excess ATO energy in testing muscle

125
Q

What is aerobic metabolism??

A

• primary energy source of testing muscles

126
Q

How many ATP are produced with aerobic metabolism?

A

• 34

127
Q

What is anaerobic glycolysis?

A

• primary energy source of peak muscular activity

128
Q

How many ATP are produced in anaerobic glycolysis?

A

• 2 ATP molecules per molecule of glucose

129
Q

What happens in anaerobic glycolysis?

A

• breaks down glucose from glycogen stores I skeletal muscles

130
Q

What happens when skeletal muscles are at rest?

A
  • it metabolizes Fatty acids

* store glycogen, build CP reserves

131
Q

What happens during moderate activity?

A

• generate ATO through aerobic breakdown of carb

132
Q

What happens if glycogen reserves are low during moderate activity?

A
  • uses lipids or amino acids

* ALL ATO is used as

133
Q

What happens during peak activity?

A
  • energy is provided by anaerobic reactions (glycolysis)

* generate lactic acid as byproduct

134
Q

What are the results of muscle fatigue??

A
  • depletion of metabolic reserves
  • damage to the sarcolemma and sarcoplasmic reticulum
  • low PH (lactic acid)
  • pain
135
Q

What happens in recovery period?

A
  • oxygen becomes available

* mitochondrial activity returns

136
Q

What is the cori cycle?

A
  • removal and recycling of lactic acid

* glucose is released from the liver to recharge muscle

137
Q

What is the oxygen debt?

A

Body needs more oxygen than usual to normalize metabolic activities
• heavy breathing

138
Q

What is another name for oxygen debt?

A

• excess post exercise oxygen consumption (EPOC)

139
Q

Up to what percent can be lost in heat?

A

• 70% of muscle energy

140
Q

What is the only muscle tissue part of the muscular system?

A

• skeletal muscle tissue

142
Q

What are the 4 hormones of muscle metabolism?

A
  1. Growth hormone
  2. Testosterone
  3. Thyroid hormone
  4. Epinephrine
143
Q

What do fast fibers do?

A

• contract very quickly

144
Q

Describe fast fibers

A
  • larger in diameter
  • large glycogen reserves
  • few motors
  • strong contraction
  • fatigue fast
145
Q

What do slow fibers do?

A

• contract slowly and slow to fatigue

146
Q

Describe slow fibers

A
  • small in diameter
  • more mitos
  • high oxygen supply
  • contain myoglobin
147
Q

What are intermediate fibers?

A

• mid sized fibers

148
Q

Describe intermediate fibers

A
  • resemble fast fibers

* have intermediate capillary network and mitochondrial content

149
Q

What are white muscles mostly formed by?

A

• fast fibers

150
Q

What are red muscles mostly formed by?

A

• slow fibers

151
Q

What types of fibers do most humans have

A
  • mixed fibers

* pink appearance

152
Q

What is hypertrophy?

A

• muscle growth from heavy training

153
Q

What happens in hypertrophy?

A
  • increase diameter of muscle fiber
  • increase number of myofibrils
  • increase mitochondria
  • increase glycogen reserves
154
Q

What is atrophy?

A

• lack of muscle activity

155
Q

What happens in atrophy?

A
  • reduced muscle size

* reduce in tone and power

156
Q

What kind of fibers are used in anaerobic activities?

A

• fast fibers

157
Q

What are some examples of anaerobic activities?

A
  • 59 meter dash

* weightlifting

158
Q

What is aerobic activities?

A
  • prolonged activities
  • swimming
  • jogging
  • aerobic classes
159
Q

How is aerobic activities supported?

A

• by mitochondria

160
Q

How is aerobic endurance improved?

A

• training fast fibers to be more like intermediate fibers

161
Q

Where are cardiac muscles found?

A
  • only in the heart

* they are striated

162
Q

Describe cardiac muscles

A
  • small
  • single nucleus
  • short, wide T tubules
  • no terminal cisternae
  • are aerobic
  • have intercalated discs
163
Q

What are intercalated discs?

A

• specialized contact points between cardio cures

164
Q

What are the functions of intercalated discs?

A
  • maintain structure

* enhance molecular and connections to potentials

165
Q

What are the functional characteristics of a cardiac muscle tissue?

A
  • automaticity
  • variable contraction tension
  • extended contraction time
166
Q

What is automaticity?

A
  • contraction w/o neural stimulation

* co trolled by pace makers

167
Q

What is variable contraction tension?

A

• controlled by nervous system

168
Q

What is extended contraction time?

A

• 10x as long as skeletal muscle

169
Q

Where does smooth muscle form?

A
  • around other tissues
  • integumentary
  • digestive
  • urinary
  • reproductive system
170
Q

What signals the stimulus for ACh release? Stp2

A
  • arrival of an electrical impulse

* action potential at the axon terminal

170
Q

What are the characteristics of smooth muscle?

A
  • nonstriated tissue

* different internal organization of actin and myosin

171
Q

Describe smooth muscle

A
  • long and slender
  • single central nucleus
  • no T tubules myofibrils or sarcomeres
  • No tendon or aponeuroses
  • scattered myosin fibers
  • thin filaments attached to dense bodies
  • dense bodies transmit contraction from cell to cell