Chp10- Muscle Tissues Flashcards Preview

Unit3 > Chp10- Muscle Tissues > Flashcards

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

What is a primary tissue type?

• muscle tissue

2

What are the 3 divisions of a muscle tissue?

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

3

What does skeletal muscle tissue do?

• attaches tithe skeletal system
• allows us to move

4

What are the 6 functions of skeletal 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

5

What are the components of skeletal muscle?

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

6

What are the 3 layers of connective tissue?

•Epimysium
• Perimysium
• Endomysium

7

What is the Epimysium?

• exterior collagen layer

8

What is the Epimysium connected to?

• deep fascia

9

What does the Epimysium do?

• separates muscle from surrounding tissues

10

What is the Perimysium?

• fibrous connective tissue

11

What is the Perimysium rich in??

• rich is collagen and elastin

12

What does the Perimysium surround?

• muscle fiber bundles (fascicles)

13

What does the Perimysium contain?

• blood vessels and nerve supply for the fascicles

14

What is the Endomysium?

• delicates connective tissue layer

15

What does the Endomysium surround?

• individual muscle cells/fiber

16

What does the Endomysium contain?

• capillaries and nerve fibers contacting muscle cells
• myosatellite cells (stem cells)

17

What is another name for myosatellite cells?

•Stem cells

18

What does myosatellite cells do?

• repair damage

19

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

• form connective tissue attachment

20

To what does the connective tissue attach to?

• bone matrix

21

What is the connective tissue called?

• tendon bundle
• aponeurosis sheet

22

What does muscles have ?

• extensive vascular systems

23

What does this vascular system supply to the muscle??

• oxygen
• nutrients
• carry away waste

24

How are the voluntary skeletal muscles controlled?

• nerves of the central nervous system
• brain and spinal chord

25

How do skeletal muscle cells develop?

• through the fusion of embryonic cells

26

How are the embryonic cells called?

• myoblast

27

How long can skeletal muscle cells be?

• 30 cm
• 12 inch

28

What does skeletal muscle cells contains?

• hundreds of nuclei

29

What is the sarcolemma?

• cell membrane of a muscle cell (fiber)

30

What does the sarcolemma surround?

• the sarcoplasm

31

What is the sarcoplasm?

• cytoplasm of a muscle cell

32

What begins contraction of a muscle?

• change in the transmembrane potential

33

What are the transverse tubules??

• narrow tubes that are continuous with the sarcolemma

34

What is another name for transverse tubules??

• T tubules

35

What do the T tubules do??

• transmit action potential through cell
• allow entire muscle to contract simultaneously

36

What are the properties of T tubules?

• same as sarcolemma

37

What ate myofibrils??

• lengthwise subdivision w/in muscle fibers

38

What makes up myofibrils?

• bundles of protein filaments

39

What are the protein filaments called??

• myofilaments

40

What are myofilaments responsible for?

• muscle contraction

41

What are the types of myofilaments?

• thin filaments
• thick filaments

42

What are thin filaments made up of?

• protein actin

43

What are thick filaments made up of?

• protein myosin

44

What is the sarcoplasm if reticulum (SR)?

• membranous structure surrounding each myofibril

45

What is the structure of Sarcoplasmic Reticulum?

• similar to Smooth ER

46

What does the sarcoplasmic reticulum do?

• forms chambers attached to T tubules

47

What are the chambers formed by sarcoplasmic reticulum called?

• terminal cisternae

48

What is a TRIAD composed of?

• 1 T tubule
• 2 terminal cisternae

49

What does ciaternae concentrate??

• Ca2+ via ion pumps

50

Where does the cisternae release the Ca2+?

• onto sarcomeres

51

Why does the cisternae release the Ca2+?

• to begin muscle contraction

52

What are sarcomeres??

• contractile units of muscles

53

How are myofibrils built??

• by 10k sarcomeres attached end to end

54

What do these sarcomeres form?

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

55

What are the thick filaments called?

• A bands

56

What are the thin filaments called??

• I bands

57

Where do thick and thin filaments over lap??

• in the zone of overlap

58

Where does the M line occur?

• the Middle

59

What does the Z line mark?

• boundary between adjacent sarcomeres

60

What are thin filaments made up of?

• F-acting filamentous
• nebulin
• tropomyosin
• troponin

61

What is F-acting (filamentous)?

• 2 twisted rows of globular G-acting

62

What does the active (yellow) actin site do?

• Bind to myosin

63

What does Nebulin do?

• holds F-acting strands together

64

What does Tropomyosin do?

• prevents actin-myosin interaction

65

What does Troponin do?

• binds tropomyosin to actin

66

How is troponin controlled?

• by Ca2+

67

What does the thick filaments contain?

• about 300 twisted myosin subunits
• titin

68

What does Titin do?

• recoil after stretching

69

That does the tail of the myosin molecule do?

• binds to other myosin molecules

70

What does the head of myosin molecule do?

• teaches the nearest thin filament

71

What is the head of the myosin made up of?

• 2 globular protein subunits

72

What happens during contraction to myosin head?

• interact w/ actin filaments
• for cross-bridges
• pivot

73

How is contraction initiated?

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

74

What happens to thin filaments in filament theory?

• slide towards M line

75

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

• the width of A zone stays the same

76

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

• Z line moves closer together

77

What does the process of contraction involve?

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

78

What happens in neural stimulation if sarcolemma?

• causes excitation-contraction coupling

79

What happens in over contraction??

• interaction of thick and thin filaments

80

What is the Neuromuscular Junction?

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

81

What does the neuromuscular junction control?

• calcium ion release into the sarcoplasm

82

What is the synaptic cleft?

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

83

Step 1 of neuromuscular junction.

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

84

What is acetylcholine? Stp1

• a neurotransmitter

85

What is a neurotransmitter? Stp1

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

86

What is an action potential? Step2

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

87

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

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

88

When does exocytosis occur? Stp3

• as vesicles fuse with the neuron's plasma membrane

89

What is the 1st step of contraction cycle?

1. Contraction cycle begins
• arrival of Ca2+

90

What is the 2nd step of contraction cycle?

2. Active-site exposure

91

What is the 3rd step of contraction cycle?

3. Cross-bridge formation

92

What is the 4th step of contraction cycle?

4. Myosin head pivoting

93

What is the 5th step of contraction cycle?

• Cross-bridge detachment

94

What is the 6th step of contraction cycle?

6. Myosin reactivation

95

How is tension produced?

• sarcomeres shorten
• muscle pulls together

96

Where can muscle shortening occur?

• both ends of muscle
• one end of muscle

97

What determines where the shortening happens?

• the way the muscle is attached at the ends

98

What does contraction duration depend on?

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

99

What happens when the muscle relaxes.

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

100

Is contraction an active process?

• yes

101

What does SR release?

• Ca2+

102

What triggers contraction?

• Ca2+ in the sarcoplasm

103

What happens as thin filaments slide between thick filaments?

• skeletal muscle shortens

104

Is relaxation an active or passive process??

• passive

105

What does tension production depends on?

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

106

What does a single. Rural stimulation produce?

• single contraction or twitch

107

How long does a single twitch last?

• 7-100 milliseconds

108

What does sustain muscular contraction require?

• many stimuli

109

What are the 3 stages of a twitch?

1. latent period
2. Contraction phase
3. Relaxation phase

110

How long does latent period last?

• 2 msec

111

How long does contraction phase last

• 15 Msec

112

How long does relaxation phase last?

• 25 msec

113

What is a treppe?

• stair-step increase in twitch tension
• < 50/sec

114

What is same summation?

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

115

What is Incomplete tetanus

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

116

What is complete tetanus?

• strings frequency is high enough
• relaxation phase is completely eliminated

117

What does motor units contain?

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

118

What is isotonic contraction?

• skeletal muscle changes length

119

What are the 2 types of isotonic contraction?

• Concentric
• Eccentric

120

What is concentric contraction?

• muscle shortens
• tension is greater than load

121

What is eccentric contraction?

• muscle lengthens
• muscle tension is lesser than load

122

What is isometric contraction?

• skeletal muscle does not change in length
• still develops tension

123

What happens when as the heavier the load?

• longer time for shortening to begin
• less muscle will shorten

124

What is creating phosphate?

• storage molecule for excess ATO energy in testing muscle

125

What is aerobic metabolism??

• primary energy source of testing muscles

126

How many ATP are produced with aerobic metabolism?

• 34

127

What is anaerobic glycolysis?

• primary energy source of peak muscular activity

128

How many ATP are produced in anaerobic glycolysis?

• 2 ATP molecules per molecule of glucose

129

What happens in anaerobic glycolysis?

• breaks down glucose from glycogen stores I skeletal muscles

130

What happens when skeletal muscles are at rest?

• it metabolizes Fatty acids
• store glycogen, build CP reserves

131

What happens during moderate activity?

• generate ATO through aerobic breakdown of carb

132

What happens if glycogen reserves are low during moderate activity?

• uses lipids or amino acids
• ALL ATO is used as

133

What happens during peak activity?

• energy is provided by anaerobic reactions (glycolysis)
• generate lactic acid as byproduct

134

What are the results of muscle fatigue??

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

135

What happens in recovery period?

• oxygen becomes available
• mitochondrial activity returns

136

What is the cori cycle?

• removal and recycling of lactic acid
• glucose is released from the liver to recharge muscle

137

What is the oxygen debt?

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

138

What is another name for oxygen debt?

• excess post exercise oxygen consumption (EPOC)

139

Up to what percent can be lost in heat?

• 70% of muscle energy

140

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

• skeletal muscle tissue

142

What are the 4 hormones of muscle metabolism?

1. Growth hormone
2. Testosterone
3. Thyroid hormone
4. Epinephrine

143

What do fast fibers do?

• contract very quickly

144

Describe fast fibers

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

145

What do slow fibers do?

• contract slowly and slow to fatigue

146

Describe slow fibers

• small in diameter
• more mitos
• high oxygen supply
• contain myoglobin

147

What are intermediate fibers?

• mid sized fibers

148

Describe intermediate fibers

• resemble fast fibers
• have intermediate capillary network and mitochondrial content

149

What are white muscles mostly formed by?

• fast fibers

150

What are red muscles mostly formed by?

• slow fibers

151

What types of fibers do most humans have

• mixed fibers
• pink appearance

152

What is hypertrophy?

• muscle growth from heavy training

153

What happens in hypertrophy?

• increase diameter of muscle fiber
• increase number of myofibrils
• increase mitochondria
• increase glycogen reserves

154

What is atrophy?

• lack of muscle activity

155

What happens in atrophy?

• reduced muscle size
• reduce in tone and power

156

What kind of fibers are used in anaerobic activities?

• fast fibers

157

What are some examples of anaerobic activities?

• 59 meter dash
• weightlifting

158

What is aerobic activities?

• prolonged activities
• swimming
• jogging
• aerobic classes

159

How is aerobic activities supported?

• by mitochondria

160

How is aerobic endurance improved?

• training fast fibers to be more like intermediate fibers

161

Where are cardiac muscles found?

• only in the heart
• they are striated

162

Describe cardiac muscles

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

163

What are intercalated discs?

• specialized contact points between cardio cures

164

What are the functions of intercalated discs?

• maintain structure
• enhance molecular and connections to potentials

165

What are the functional characteristics of a cardiac muscle tissue?

• automaticity
• variable contraction tension
• extended contraction time

166

What is automaticity?

• contraction w/o neural stimulation
• co trolled by pace makers

167

What is variable contraction tension?

• controlled by nervous system

168

What is extended contraction time?

• 10x as long as skeletal muscle

169

Where does smooth muscle form?

• around other tissues
• integumentary
• digestive
• urinary
• reproductive system

170

What signals the stimulus for ACh release? Stp2

• arrival of an electrical impulse
• action potential at the axon terminal

170

What are the characteristics of smooth muscle?

• nonstriated tissue
• different internal organization of actin and myosin

171

Describe smooth muscle

• 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