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Anatomy and physiology I lecture > muscles and muscle tissue LECTURE > Flashcards

muscles and muscle tissue LECTURE Flashcards

1
Q

______ muscle is

  • not striated
  • found in the intestine, respiratory, blood vessels
  • involuntary, autonomic nervous system, hormones
A

Smooth

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2
Q

____ muscle is

  • striated
  • found in heart
  • involuntary, autonomic nervous, hormones
A

Cardiac

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3
Q

____ muscle is

  • striated
  • voluntary, learned patterns of movement
A

Skeletal

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4
Q

Which muscle is attached to skin and bones?

A

Skeletal

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5
Q

Is cardiac muscle only found in the heart?

A

Yeah, duh

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6
Q

Is cardiac muscle striated?

A

Yes

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7
Q

Is cardiac muscle involuntary?

A

Yes

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8
Q

Is smooth muscle striated?

A

NO

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9
Q

Is smooth muscle voluntary?

A

No

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10
Q

Is smooth muscle tissue found in the walls of hollow organs?

A

Yes

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11
Q

Excitability is the ability to ____ and ____ to stimuli

A

receive and respond

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12
Q

Contractility is the ability to ____ when stimulated

A

shorten

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13
Q

Extensibility is the ability to be ______

A

Stretched

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14
Q

Elasticity is the ability to ____ to resting length

A

Recoil

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15
Q

In skeletal muscle structures, ______ is dense irregular connective tissue surrounding the entire skeletal muscle

A

Epimysium

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16
Q

In skeletal muscle structures, ______ is dense irregular connective tissue surrounding muscle fasciculi

A

Perimysium

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17
Q

In skeletal muscle structures, ______ is loose areolar connective tissue surrounding muscle fibers

A

Endomysium

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18
Q

Which skeletal muscle structure surrounds the entire skeletal muscle?

A

Epimysium

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19
Q

Which skeletal structure surrounds the muscle fasciculi?

A

Perimysium

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20
Q

which skeletal structure surrounds the muscle fibers?

A

Endomysium

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21
Q

Muscles attach directly and ______

A

indirectly

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22
Q

Muscles attach directly, ______ of muscle is fused to the Periosteum of bone

A

Epimysium

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23
Q

Muscles attach indirectly, connective tissue wrappings extend beyond the muscle as rope like _____

A

tendon

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24
Q

Which is more common, muscles that attach directly or indirectly?

A

Indirectly

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25
Q

Directly or indirectly? “epimysium of muscle is fused to the periosteum of bone”

A

Directly

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26
Q

Dir or indirectly? “connective tissue wrappings extend beyond the muscle as a roselike tendon”

A

Indirectly

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27
Q

In direct muscle attachment, the epimysium of the muscle is fused to which part of the bone?

A

The periosteum of the bone

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28
Q

In indirect attachment of muscles, connective tissue wrappings extend beyond the muscle as rope like ______.

A

Tendon

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29
Q

Does skeletal muscle have multiple nuclei?

A

Yes

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30
Q

Does skeletal muscle have many mitochondria?

A

Yes

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31
Q

_______ muscle contains myofibrils, sarcoplasmic reticulum, and T-tubules.

A

Skeletal

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32
Q

Does skeletal muscle contain glycosomes?

A

Yes

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33
Q

In skeletal muscle, glycosomes is used to store glycogen. True or false?

A

True

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34
Q

What are densely packed, rodlike elements? Myofibrils or t-tubules?

A

Myofibrils

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35
Q

Do myofibrils exhibit striations?

A

Yes

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36
Q

______ have perfectly aligned repeating series of dark _ bands and light _ bands

A

Myofibrils have perfectly aligned repeating series of dark A bands and light I bands

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37
Q

_____ : A protein fiber network which forms attachment sites for actin myofilamints

A

Z-disk

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38
Q

____: Consists of actin (thin filaments) which spans each z disk and ends at the myosin myofilaments

A

I band (light)

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39
Q

____: extends the length of the myosin myofilaments (thick filaments)

A

A band (dark)

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40
Q

____: Filaments do not overlap

A

H zone

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41
Q

____: consists of protein myomesin which holds the thick filaments together

A

M line

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42
Q

What is the smallest contractile unit of a muscle fiber?

A

Sarcomere

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43
Q

_____ is the region of a myofibril between two successful z discs

A

Sarcomere

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44
Q

_____ are composed of thick and thin myofilaments made of contractile proteins

A

Sarcomere

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45
Q

In a sarcomere, is myosin a thick or thin filament?

A

Thick

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46
Q

In a sarcomere, is actin a thick or thin filament?

A

Thin

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47
Q

In a sarcomere, is troponin a thick or thin filament?

A

thin

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48
Q

In a sarcomere, is tropomyosin a thick or thin filament?

A

thin

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49
Q

In a sarcomere, is Titin a structural protein?

A

Yes

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50
Q

In a sarcomere, is M-line a structural protein?

A

Yes

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51
Q

In a sarcomere, is a z-disk a structural protein?

A

Yes

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52
Q

_____, ______, and _____ are structural proteins of a sarcomere

A

Titan, M-line, and z-disk

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53
Q

______ is a contractile protein in thick filament

A

Myosin

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54
Q

______ is a contractile protein in thin filament

A

Actin

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55
Q

______ is a regulatory protein in thin filament (binds calcium)

A

Troponin

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56
Q

______ is a regulatory protein in thin filament

A

Tropomyosin

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57
Q

______ is a structural protein; stretching (springs)

A

Titin

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58
Q

______ is a structural protein (M-LINE) anchors myosin

A

Myomesin

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59
Q

Which muscle protein anchors myosin?

A

Myomesin

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60
Q

______ is a structural protein that anchors actin

A

Z-disk

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61
Q

Which muscle protein anchors actin?

A

Z-disks

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62
Q

Which muscle protein binds calcium?

A

Troponin

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63
Q

Which muscle protein is found in thick filament, myosin or actin?

A

Myosin

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64
Q

Which muscle protein is found in thin filament, Myosin or actin?

A

Actin

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65
Q

Does tropomyosin bind calcium?

A

No, troponin does

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66
Q

Which muscle protein stretches?

A

Titin

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67
Q

The ultrastructure of Thick Filament is composed of Myosin ______ and ______

A

heads and tails

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68
Q

In the ultrastructure of thick filament, the myosin tails contain two interwoven, heavy ______ chains

A

Polypeptide

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69
Q

Do myosin tails contain interwoven polypeptide tails?

A

Yes

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70
Q

in the ultrastructure of thick filament, myosin heads contain 2 smaller, light ______ chains that act as cross bridges during ________

A

Polypeptide, during contraction.

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71
Q

What is the binding sites for actin of thin filaments, the myosin heads or tails?

A

Heads

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72
Q

What is the binding site for ATP, myosin tails or heads?

A

heads

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73
Q

ATPase enzymes occur at myosin _____

A

heads

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74
Q

Thick filament is composed of the protein _______

A

Myosin

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75
Q

What are myosin tails composed of in the thick filament?

A

2 interwoven, heavy polypeptide chains

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76
Q

______:
-act as cross bridges during contraction
binding sites for ATP
ATPase enzymes

A

Myosin heads

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77
Q

In the ultrastructure of thin filament, twisted double strands of fibrous protein are called ____

A

F actin (fibrous actin)

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78
Q

In the ultrastructure of thin filament, F actin consists of ______ subunits

A

G actin (globular)

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79
Q

In the ultrastructure of thin filament, G actin bears active sites for ____ ____ attachment during contraction

A

myosin head

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80
Q

In the ultrastructure of thin filament ______ and _____ are regulatory proteins bound to actin

A

Tropomyosin and troponin

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81
Q

“Twisted double strand of fibrous protein: F actin” Thick or thin filament?

A

Thin

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82
Q

“f actin consists of g actin subunits” Thick or thin?

A

thin

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83
Q

During contraction, which actin bears active sites for myosin head attachment?

A

G-Actin

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84
Q

Which two regulatory proteins bind to actin?

A

Tropomyosin and troponin

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85
Q

_____: the generation of force

A

Contraction

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86
Q

______ does not necessarily cause shortening of the fiber

A

Contraction

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87
Q

In a contraction, shortening occurs when tension generated by ____ ____ on the _____(thick or thin?) filaments exceeds forces opposing shortening

A

cross bridges; thin

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88
Q

Do contractions always cause shortening of the fiber?

A

No

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89
Q

during contraction, myosin _____ bind to actin, detach, and bind again, to propel _____ filaments towards the ___line.

A

heads; thin; M

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90
Q

During contractions, do myosin heads propel towards the M line after binding to actin, detaching, and then binding again?

A

yes

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91
Q

Tropomyosin blocks the active sites on actin when….

A

you have low intracellular Ca2+

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92
Q

Myosin heads cannot attach to actin when…..

A

you have low intracellular Ca2+

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93
Q

Muscle fiber relaxes when….

A

you have low intracellular Ca2+

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94
Q

Ca2+ binds to troponin when you have…..

A

high intracellular Ca2+ concentrations

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95
Q

Troponin changes shape and moves tropomyosin away from active sites when you have…

A

high intracellular Ca2+ concentrations

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96
Q

At high intracellular Ca2+ concentrations, events of the ___ ____ ___ occur

A

Cross bridge cycle

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97
Q

When nervous stimulation ceases, ______ is pumped back into the SR and contraction ends

A

Ca+2

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98
Q

Ca2+ is pumped back into the SR and contraction ends when….

A

nervous stimulation ceases

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99
Q

Ca2+ is pumped back into the SR and contraction ends at high concentrations of

A

Ca+2

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100
Q

For the cross bridge cycle to continue, a Ca2+ ____ and adequate _____ must be present

A

signal; ATP

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101
Q

In cross bridge formation, high energy myosin ____ attaches to _____ filament

A

Heads attach to thin filament

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102
Q

Working (power) stroke in the cross bridge cycle occurs when the myosin _____ pivots and pulls thin filament toward the ____ line

A

Myosin head pivots and pulls thin filament toward the M Line

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103
Q

In the cross bridge cycle, ATP attaches to myosin heads and the cross bridge detaches. This is called _____ ____ ___

A

Cross Bridge detachment

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104
Q

In the cross bridge cycle, energy from hydrolysis of ATP cocks the myosin head into the high-energy state. This is called _____ of the ____ ____

A

Cocking of the myosin head

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105
Q

The _____ ____ is a network of smooth endoplasmic reticulum surrounding each myofibril

A

Sarcoplasmic Reticulum (SR)

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106
Q

The _____ _____ has pairs of terminal cisternae that form perpendicular cross channels

A

Sarcoplasmic Reticulum

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107
Q

The _____ _____ functions in the regulation of intracellular Ca2+ levels

A

Sarcoplasmic reticulum

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108
Q

What is the function of the SR?

A

Regulation of intracellular ca2+ levels

109
Q

The SR is a network of smooth endoplasmic reticulum surrounding each _______

A

Myofibril

110
Q

The SR has pairs of terminal ______ that form perpendicular ____ ____

A

cisternae; cross channels

111
Q

_ _______ are continuous with the sarcolemma

A

T Tubules

112
Q

_ ________ associate with the paired terminal cisternae of sarcoplasmic reticulum to form triads that encircle each sarocmere

A

T Tubules

113
Q

T tubules associate with the paired _____ _____ of the ______ _____

A

terminal cisternae; sarcoplasmic reticulum

114
Q

What associates with the paired terminal cisternae?

A

T Tubules

115
Q

__ _____ conduct impulses deep into muscle fiber

A

T Tubules

116
Q

____ _____ protrude into the inter membrane space from T tubule and SR cisternae membranes

A

Integral proteins

117
Q

__ ____ ____ are gated channels that regulate Ca2+ release from the SR cisternae

A

SR foot proteins

118
Q

What conducts impulses deep into muscle fiber?

A

T tubules

119
Q

What protrudes into the inter membrane space from T tubule and SR cisternae membranes?

A

Integral Proteins

120
Q

SR foot proteins are gated channels that regulate ____ release from the SR _______

A

Ca2+; Cisternae

121
Q

Integral proteins protrude into the inter membrane space from ______ and ___ _____ membranes

A

T tubules and SR cisternae

122
Q

What are the two requirements for skeletal muscle contraction?

A

Activation and excitation-contraction coupling

123
Q

_____ is neural stimulation at a neuromuscular junction

A

Activation

124
Q

______-_______ _____ is a generation and propagation of an action potential along the sarcolemma

A

Excitation-contraction coupling

125
Q

____-____ ____ has a final trigger, which is a brief rise in intracellular ca2+ levels

A

Excitation contraction coupling

126
Q

What is the final trigger in the excitation-contraction coupling?

A

A brief rise in intracellular ca2+ levels

127
Q

A requirement for skeletal muscle contraction is activation, which is a ____ _____ at a neuromuscular junction

A

neural stimulation

128
Q

Skeletal muscles are stimulated by somatic ____ _____

A

motor neurons

129
Q

Axons of motor neurons travel from the ____ ____ _____ via nerves to _____ _____

A

central nervous system; skeletal muscles

130
Q

Each ____ ending forms a ____ _____ with a single muscle fiber

A

Each axon ending forms a neuromuscular junction with a single muscle fiber

131
Q

What are skeletal muscles stimulated by?

A

Somatic motor neurons

132
Q

A neuromuscular junction is situated midway along the length of a ____ ____

A

muscle fiber

133
Q

Axon terminal and muscle fiber are separated by a gel-filled space called the _____ _____

A

synaptic cleft

134
Q

Synaptic vesicles of axon terminals containing the neurotransmitter ______ (ACh)

A

Acetylcholine

135
Q

Junctional folds of the sarcolemma contain _____ receptors

A

ACh

136
Q

What is the synaptic cleft?

A

Gel-filled space

137
Q

Which enzyme quickly terminates ACh?

A

Acetylcholinesterase

138
Q

The destruction of ACh prevents continued ____ ____ ___ in the absence of additional stimulation

A

muscle fiber contraction

139
Q

Resting cell membrane potential is also called _______

A

Polarization

140
Q
  1. Concentration of K+ inside the cell is greater than the outside of the cell
  2. Na+ outside the cell is greater than inside the cell.

This means the cell is ________

A

Polarized

141
Q

To depolarize a cell, there must be simultaneous diffusion of _____ inward and _____ outward

A

Na+ and K+

142
Q

The interior of the sarcolemma becomes less negative the more _____ diffuses

A

Na+

143
Q

End plate potential is when ____ _____ occurs

A

local depolarization

144
Q

One event in the generation of an action potential, end plate potential spreads to ____ ____ areas

A

adjacent membrane

145
Q

Do voltage-gates Na+ channels need to open to generate action potential?

A

Yes

146
Q

Does the Na+ influx decrease the membrane voltage toward a critical threshold?

A

Yes

147
Q

When can action potential finally be reached?

A

When the threshold is reached

148
Q

Local ______ waves continue to spread, changing the permeability of the sarcolemma.

A

depolarization

149
Q

Voltage-regulated Na+ channels open in the ____ ____, causing it to depolarize to threshold

A

Adjacent patch

150
Q

To repolarize, ____ channels close and voltage-gated _____ channels open

A

Na+ ; K+

151
Q

_____ efflux rapidly restores the resting polarity

A

K+

152
Q

Fiber cannot be stimulated and is in a _____ period until repolarization is complete

A

refractory

153
Q

ionic conditions of the resting state are restored by the _______ pump

A

Na+-K+ pump

154
Q

Signal to the muscle cell:

  1. _____ ____ travels down the cell
  2. Moves into the cell through the _ ______
  3. Triggers release of _____ from _____ ______
  4. _____ binds with troponin, releasing the ____ ____ ___
  5. muscle contraction
A
  1. action potential
  2. T Tubules
  3. Ca++ from sarcoplasmic reticulum
  4. Ca++ binds with troponin releasing the myosin binding sites
155
Q

AP id propagated along the _____ to the T-tubules

A

Sarcomere

156
Q

What is necessary for contraction, CA2+ or vitamin D?

A

Ca2+

157
Q
  1. Tropomyosin blocks the active sites on the actin
  2. myosin heads cannot attach to actin
  3. Muscle fibers relax. This describes which kind of Ca2+ concentration?
A

Low levels

158
Q

At higher intracellular levels of Ca2+, calcium binds to _____

A

Troponin

159
Q

After ca2+ binds to troponin, it changes shape and moves the ____ away from the active sites

A

Tropomyosin

160
Q

When the tropomyosin has been moved away from the active sites, the ____ ____ cycle occurs

A

Cross bridge

161
Q

When the stimulation ceases, Ca2+ is pumped back into the _____ _____ and contraction ends

A

Sarcoplasmic reticulum

162
Q

In an _____ ______, no shortening; muscle tension increases but does not exceed the load

A

Isometric contraction

163
Q

In an ______ _____, muscle shortens because muscle tension exceeds the load

A

Isotonic contraction

164
Q

In an isometric contraction there is no ______, the muscle tension increases but ___ ___ exceed the load

A

shortening; does not

165
Q

In an isotonic contraction, the muscle shortens because….?

A

because the muscle tension exceeds the load

166
Q

A ____ ____ is a motor neuron and all muscle fibers it supplies

A

Motor unit

167
Q

A motor unit is a motor neuron and all ___ ____ it supplies

A

muscle fibers

168
Q

_____ motor units are in muscles that control fine movements (fingers, eyes)

A

Small

169
Q

_____ motor units in large weight-bearing muscles

A

Large

170
Q

Are muscle fibers in a motor unit spread throughout the muscle?

A

Yes

171
Q

Why are muscle fibers within a motor unit spread throughout the muscle?

A

SO that a single motor unit causes weak contraction of an entire muscle

172
Q

Motor units in a muscle contract _______, which helps prevent fatigue

A

asynchronously

173
Q

What do motor units do to prevent fatigue?

A

They contract asynchronously

174
Q

Three phases of a twitch

  1. _____ ____: events of excitation-contraction coupling
  2. ___of____: cross bridge formation; tension increases
  3. ____of_____: Ca2+ reentry into the SR; tension declines to zero
A
  1. Latent Period
  2. period of contraction
  3. Period of relaxation
175
Q

The three phases of a twitch include the latent period, which are the vents of ____ -_____ coupling

A

Excitation-contraction

176
Q

The three phases of contraction includes the period of contraction. This period is the ___ ____ formation, and tension increases

A

Cross bridge

177
Q

The period of relaxation, one of the three twitch phases, is when ____ reenters the SR and tension declines to 0

A

Ca2+

178
Q

Graded muscle responses are graded by

1. Changing the ______ of the ______

A

frequency of stimulation

179
Q

Graded muscle responses are graded by

2. Changing the _____ of the ______

A

strength of the stimulus

180
Q

Further increase in stimulus frequency results in ____ tetanus

A

unfused

181
Q

During a change in stimulus frequency, a Ca2+ release stimulates further contraction, and is called _____ _____

A

temporal summation

182
Q

___ _____ : stimulus strength at which the first observable muscle contraction occurs

A

Threshold stimulus

183
Q

Isotonic contractions are either _____ or _____

A

Concentric or eccentric

184
Q

_____ contractions: the muscle shortens and does work

A

concentric

185
Q

____ contractions: The muscle contracts as it lengthens

A

Eccentric

186
Q

___ Is the only source used directly for contractile activities

A

ATP

187
Q

Available stores of ATP are depleted in ___ to ___ seconds

A

4 to 6

188
Q

ATP is regenerated by direct _____ of ADP by _____ phosphate

A

phosphorylation of ADP by creatine phosphate

189
Q

ATP is regenerated by _____ which is an ______ pathway

A

Glycolysis; anaerobic

190
Q

ATP is regenerated by ______ respiration

A

aerobic

191
Q

Creatine phosphate stores ____ seconds of ATP

A

15

192
Q

Anaerobic respiration is also called:

A

II A

193
Q

Creatine phosphate is also called:

A

II B

194
Q

Aerobic respiration is also called

A

I

195
Q

Anaerobic respiration requires Glucose -> _ lactic acid and _ ATP

A

2 and 2

196
Q

aerobic respiration is limited by?

A

Gas exchange

197
Q

Aerobic respiration: myoglobin stores ____

A

oxygen

198
Q

Anaerobic respiration has ___ to ___ seconds of activity

A

30 to 40

199
Q

___ ___ buildup occurs during anaerobic respiration

A

Lactic acid

200
Q

Oxygen delivery is impaired with the _____ pathway

A

Anaerobic

201
Q

____ acid is converted into ____ acid in the anaerobic pathway

A

Pyruvic; lactic

202
Q

___ ___ diffuses into the blood stream

A

Lactic acid

203
Q

___ ___ is used as fuel by the liver, kidneys, and heart

A

Lactic Acid

204
Q

___ ___ is converted back into pyruvic acid by the _____

A

lactic acid; liver

205
Q

____ pathway produces 95% of ____ during rest and light to moderate exercise

A

aerobic pathway; ATP

206
Q

The ____ pathway stores _____, then bloodborne glucose, ____ acid from glycolysis, and free fatty acids

A

Aerobic; glycogen; pyruvic acid.

207
Q

Which pathway stored free fatty acids?

A

Aerobic

208
Q

Force of contraction is affected by: _____ and the relative size of _____

A

Recruitment; size of fibers

209
Q

Hypertrophy of cells increases _____

A

strength

210
Q

THe number of muscle fibers stimulated is also known as _____

A

recruitment

211
Q

Speed of contraction is controlled by the speed at which _____ ATPases split ____

A

myosin; ATP

212
Q

Speed of contractions is controlled by the pattern of electrical activity of the ____ ____

A

motor neurons

213
Q

Oxidative fibers use ____ pathways

A

aerobic

214
Q

Glycolytic fibers use ____ glycolysis

A

anaerobic

215
Q

Slow oxydative fibers are also called:

A

Type I

216
Q

Fast oxydative fibers are called

A

Type II A

217
Q

Fast glycolytic fibers are called

A

Type II B

218
Q

“Thin, aerobic, slow twitch, many capillaries, myoglobin Resistant to fatigue” This is? (type I)

A

Slow oxydative fibers

219
Q

“Medium thickness, aerobic, fast twitch,
many capillaries, myoglobin, high glycogen
Moderate resistant to fatigue
“This is? (Type IIA)

A

Fast oxydative fibers

220
Q

“Very thick, anaerobic, fast, powerful twitch,
high glycogen, few capillaries and myoglobin
Fatigues easily
“ This is? (Type II B)

A

Fast glycolytic fibers

221
Q

Are slow, oxydative fibers thick?

A

No, they are thin and aerobic.

222
Q

Are slow oxydative fibers resistant to fatigue?

A

Yes

223
Q

Are slow oxydative fibers also named Type II B?

A

No, they are type I

224
Q

Fast oxydative fibers have medium thickness, aerobic, and result in fast twitches. true or false?

A

True

225
Q

Do fast oxydative fibers have a moderate resistance to fatigue?

A

Yes

226
Q

Do fast oxidate fibers lack capillaries?

A

No, they have many

227
Q

Do all three types of muscle fibers have myoglobin?

A

Yes

228
Q

Do fast glycolytic fibers fatigue easily?

A

Yes

229
Q

Which muscle fiber fatigues easily? Which one is very resistant to fatigue?

A

Type II B(fast glycol) and Slow oxydative (type I)

230
Q

Name the muscle fibers from thickest to thinnest.

A

Fast glycolytic
fast oxy
slow oxy

231
Q

Name the two layers of smooth muscle

A

Longitudinal and circular

232
Q

Where is smooth muscle found?

A

Walls of most hollow organs

233
Q

______ is the alternating contractions and relaxations of smooth muscle layers

A

Peristalsis

234
Q

When _____ layer of smooth muscle contracts, the organ dilates and shortens

A

Longitudinal

235
Q

when ______ layer of smooth muscle contracts, the organ constricts and elongates

A

Circular

236
Q

This describes which microscopic structure of smooth muscle? “thin and short compared with skeletal muscle fibers
“

A

Spindle-shaped fibers

237
Q

In smooth muscle, ____ ____ is only found in the endomysium

A

Connective tissue

238
Q

In smooth muscle, the _____ _____ is less developed than in skeletal muscle

A

Sarcoplasmic reticulum

239
Q

Pouch like inholdings (caveolae) of the sarcolemma sequester Ca2+. This describes which microscopic type of muscle?

A

Smooth

240
Q

Does smooth muscle contain sarcomeres, myofibrils or T tubules?

A

No

241
Q

_____ _____ ___ innervate smooth muscle at diffuse junctions

A

Autonomic nerve fibers

242
Q

_______ of nerve fibers store and release neurotransmitters

A

Varicosities

243
Q

In skeletal muscle, the ratio of thick to thin filaments is 1:2. In smooth muscles, it is what?

A

1:13

244
Q

Thick filaments have heads along their entire length in which type of muscle?

A

Smooth

245
Q

Troponin in skeletal muscle binds to calcium. However, in smooth muscle, the protein _____ binds calcium

A

Calmodulin

246
Q

How are myofilaments in smooth muscle arranges?

A

Spirally

247
Q

Because myofilaments in smooth muscle are spirally arranged, this causes smooth muscle to contract in what type of manner?

A

A corkscrew manner

248
Q

Smooth muscle has ____ bodies

A

Dense

249
Q

Smooth muscle has dense bodies: proteins that anchor non contractile intermediate filaments to _____ at regular intervals

A

Sarcolemma

250
Q

Smooth muscle has slow, _______ contractions

A

Synchronized

251
Q

Some smooth muscle cells are self_______

A

excitatory

252
Q

Some smooth muscle cells are self-excitatory, which means they ______ without external stimuli

A

depolarize

253
Q

______ and _____ stimuli may modify the rate and intensity of a smooth muscle contraction

A

Neural and chemical

254
Q

In smooth muscle, Ca2+ binds to and activates _______

A

Calmodulin

255
Q

In smooth muscle, activates calmodulin activates _____ kinase

A

myosin

256
Q

In smooth muscle, activated kinase _______ and activates myosin

A

phosphorylates

257
Q

After the activates kinase phosphorylates and activates myosin, the ____ ____ interact with actin

A

Cross bridges

258
Q

Are the contractions of smooth muscle energy efficient?

A

Yes

259
Q

in smooth muscle, Myofilaments may maintain a latch state for prolonged ______

A

contractions

260
Q

Relaxation of smooth muscle requires that ____ detaches from the calmodulin

A

Ca2+

261
Q

Relaxation of smooth muscle contractions requires active transport of Ca2+ into the _____ _____

A

sarcoplasmic reticulum

262
Q

Relaxation of smooth muscle contractions requires the dephosphorylation of _____ to reduce ATPase activity

A

myosin

263
Q

Multiunit smooth muscle is located in large airways. True or false?

A

True

264
Q

which type of smooth muscle is found in arrector pili muscles?

A

Multiunit

265
Q

Are gap junctions rare in multiunit smooth muscle?

A

Yes

266
Q

How is multiunit smooth muscle arranged?

A

In motor units

267
Q

Do large arteries contain multiunit skeletal muscle?

A

No, they contain multiunit smooth muscle

268
Q

____ _____ occur in response to neural stimuli (smooth multiunit muscle)

A

Graded contractions

Anatomy and physiology I lecture (14 decks)

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