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Pathophys II - Exam 2 > Mace - Muscle > Flashcards

Mace - Muscle Flashcards

1
Q

what are the 3 types of muscle tissue

A

skeletal

cardiac

smooth

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2
Q

what causes skeletal muscle to look striated

A

alternating light and dark bands

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3
Q

skeletal muscle is __ and

under __ control

A

voluntary

conscious

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4
Q

describe the structure of skeletal muscle fibers (cells)

A

long, unbranched, cylindrical

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4
Q

describe the arrangement of skeletal muscle tissue

A

parallel bundles that run the length of the entire muscle

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5
Q

skeletal muscle is __nucleated,

which are positioned __ to the cell membrane

A

multi

adjacent

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6
Q

where is skeletal muscle found (3)

A

bone

skin

surrounding distal ends of digestive and urinary tracts as sphincters

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7
Q

the contraction of skeletal muscle tissue causes (3)

A

bone movement

facial expression

defection or urination

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8
Q

describe the structure of cardiac muscle tissue

A

short, branched cardiac muscle cells

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9
Q

describe the nuclei of cardiac muscle tissue

A

one or two centrally located

mitochondria-rich

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10
Q

cardiac muscle tissue is __

and __,

with cells that are

__ in one direction

A

striated

branched

closely packed

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11
Q

what are intercalated discs

A

junction between cells

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12
Q

what is the fxn of intercalated discs (2)

A

strengthens attachments between cells

promotes rapid conduction of electrical activity thru cardiac cells

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13
Q

is cardiac muscle voluntary or involuntary

A

involuntary

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14
Q

what is meant by syncytium of cardiac muscle tissue

A

its structure allows for rapid coordination of muscles along the entire length

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15
Q

describe the structure of smooth muscle tissue cells

A

spindle shaped

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16
Q

describe the arrangement of smooth muscle tissue cells (3)

A

short

closely packed in one direction

branched

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17
Q

smooth muscle tissue cells have __ nuclei, which is

__ located

A

one

centrally

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18
Q

does smooth muscle tissue have striations

A

no

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19
Q

where is smooth muscle tissue found

A

walls of digestive, respiratory, urinary tracts

erector pili of skin

surrounding bv

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20
Q

where in the respiratory system is smooth muscle tissue found

A

sphincters

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21
Q

smooth muscle tissue is under __ control

A

involuntary

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22
Q

what are the functions of smooth muscle tissue (5)

A

moves substances along internal passages (peristalsis)

erects hairs

controls blood flow and blood pressure

regulates airflow in lungs

controls urination and defecation

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23
Q

what are the fxns of skeletal muscle tissue (5)

A

body movement

maintenance of posture

protection and support

storage and movement of materials

heat production

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24
Q

how is skeletal muscle involved in protection and support

A

muscles along the walls of the abd and pelvic cavities protect internal organs and maintain position

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25
Q

how is skeletal muscle involved in storage and movement of materials

A

contracts and relaxes sphincters

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26
Q

how does skeletal muscle produce heat

A

byproduct of muscle contraction

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27
Q

what is the main source of heat produced w.in the body

A

byproduct of muscle contraction

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28
Q

muscle cells are organized into bundles called

A

fascicles

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29
Q

fascicles extend from

A

tendon to tendon

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30
Q

each muscle contains (3)

A

CT

blood vessels

nerves

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31
Q

what are the 3 concentric layers of CT in skeletal muscle

A

epimysium

perimysium

endomysium

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32
Q

what is the fxn of skeletal muscle (3)

A

protection

sites for bv and nerve distribution

means of attachment to skeleton or other structures

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33
Q

which layer of skeletal muscle tissue is a single layer of dense irregular CT that surrounds the entire muscle

A

epimysium

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34
Q

which layer of skeletal muscle tissue is dense irregular CT surrounding the fascicles

A

perimysium

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35
Q

which layer of skeletal muscle tissue contains extensive bv and nerve supplying fibers

A

perimysium

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36
Q

which layer of skeletal muscle tissue is made of areolar CT that surrounds and electrically insulates each muscle fibers

A

endomysium

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37
Q

what are tendons composed of

A

dense regular CT

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38
Q

tendons are __ like structures

formed by __ connective tissue layers

A

cord

3

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39
Q

what is the fxn of tendons (2)

A

attach muscle to bone

attach muscle to skin or another structure

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40
Q

aponeurosis is a type of __

with a wide area of attachment

A

tendon

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41
Q

aponeurosis is a thin, flattened sheet formed from __ connective tissue layers

A

3

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42
Q

what is the fxn of the aponeurosis

A

holds muscles together for functional enhancement

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43
Q

deep fascia is an additional sheet of

A

dense irregular CT

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44
Q

where is deep fascia located

A

external to the epimysium

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45
Q

what is the fxn of deep fascia (4)

A

separates individual muscles

binds together muscles w. similar fxns

contains nerves, bv, lymph vessels

fills spaces btw muscles

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46
Q

what is fascia made of

A

dense irregular CT

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47
Q

what is the fxn of fascia

A

separates neighboring muscles. (organs) or muscle groups from one another

separates muscles from hypodermis

makes up the inter muscular septum

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48
Q

the end, peri, and epimysium become the

A

tendons

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49
Q

when a muscle cell contracts, the pull on the __, which pull on the

__ to move bones that are attached to the muscle

A

endo, peri, and epimysium

tendons

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50
Q

skeletal muscle cells are the dominant cell in __

and contain __ proteins

A

muscle

contractile

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51
Q

what is the fxn of satellite cells

A

differentiate to repair injured muscle cells

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52
Q

do satellite cells have contractile proteins

A

no

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53
Q

what is the sarcolemma

A

membrane of the skeletal muscle cell

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54
Q

what happens at the sarcolemma during muscle contraction

A

explosive release of calcium

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55
Q

release of calcium from the sarcolemma continues as long as__ is present

A

ATP

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56
Q

T-tubues (transverse tubules) are deep invaginations of __

A

sarcolemma

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57
Q

what is the fxn of the sarcolemma

A

transmits nerve impulses from sarcolemma inward

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58
Q

what is the sarcoplasmic reticulum

A

a tubular network around contractile proteins

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59
Q

describe the structure of the sarcoplasmic reticulum

A

modified smooth endoplasmic reticulum

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60
Q

what is the fxn of the sarcoplasmic reticulum

A

stores calcium to release into sarcoplasm during muscle contraction

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61
Q

what are the dilated ends of the sarcoplasmic reticulum

A

terminal cisternae

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62
Q

what is the fxn of terminal cisternae

A

reservoirs for calcium ions

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63
Q

terminal cisternae combine w. T-tubules to form

A

triads

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64
Q

myoglobin is a __ protein

found in the __

A

globular

sarcoplasm

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65
Q

what is the fxn of myoglobin

A

allows muscle cells to store O2

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66
Q

the redder the muscle, the more __ it has

A

myoglobin

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67
Q

where are myofibrils located

A

sarcoplasm

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68
Q

what are the special contractile proteins of skeletal muscle

A

myofibrils

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69
Q

myofibrils account for _% of skeletal muscle volume

A

80

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70
Q

what are myofibrils composed of

A

a bundle of thick and thin myofilaments

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71
Q

what is responsible for muscle contraction

A

interactions between thick and thin filaments

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72
Q

muscles shorten along their

A

fiber axis

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73
Q

thick filaments are assembled from bundles of protein molecules called

A

myosin

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74
Q

each myosin has two __,

and each strand has a globular __

and a elongated __

A

intertwined strands

head

tail

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75
Q

the tails of myosin point

A

toward the center of thick filaments

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76
Q

the heads of myosin point

A

toward the edges of thick filaments

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77
Q

the head of myosin has a binding site for (2)

A

actin

ATP

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78
Q

actin is found on the

A

thin filament

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79
Q

the thin filament is composed of (3)

A

actin

tropomyosin

troponin

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80
Q

what is the primary component of the thin filament

A

actin

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81
Q

describe the structure of actin in the thin filament

A

two strands twisted around each other

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82
Q

each strand of actin is composed of many __ molecules

called __

A

spherical

G-actin (globular actin)

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83
Q

each strand of actin is composed of many __ molecules

called __

A

spherical

G-actin (globular actin)

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84
Q

where is the myosin binding site located

A

G-actin

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85
Q

describe the structure of tropomyosin

A

twisted string-like

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86
Q

what is the fxn of tropomyosin

A

covers myosin binding site in a non contracting muscle

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87
Q

troponin is a __ protein attached to

__

A

globular

tropomyosin

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88
Q

what is the fxn of troponin

A

binding site for Ca2+

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89
Q

what is the sarcomere made of

A

repeating functional units of myofilaments

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90
Q

what separates sarcomeres from one another

A

z discs

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91
Q

what separates sarcomeres from one another

A

z discs

92
Q

describe the structure and location of z-discs

A

specialized proteins

perpendicular to myofilaments

92
Q

describe the structure and location of z-discs

A

specialized proteins

perpendicular to myofilaments

93
Q

what is the fxn of z-discs

A

anchors for thin filaments

94
Q

I bands contain only

A

thin filaments

95
Q

I bands appear __ under a microscope

and disappear during __

A

light

maxima muscle contraction

96
Q

what is the central region of the sarcomere

A

A band

96
Q

what is the central region of the sarcomere

A

A band

97
Q

the A band contains the entire __

and partially overlapping __

A

thick filament

thin filaments

98
Q

how does the A band appear under a microscope

A

dark

99
Q

what is the central portion of the A band

A

H zone

100
Q

the H zone contains only

A

thick filaments

101
Q

the H zone disappears during

A

maximal muscle contraction

102
Q

what is the protein meshwork structure at the center of the H zone

A

M line

103
Q

what is the fxn of the M line

A

attachment site for thick filaments

104
Q

zones of the sarcomere

A
105
Q

understand the zones of the sarcomere during muscle contraction

A
106
Q

where are neuromuscular junctions located

A

where somatomotor neuron innervates muscle

107
Q

how many neuromuscular junctions does each cell have

A

1

108
Q

what are the components of the neuromuscular junction (3)

A

synaptic knob

motor end plate

synaptic cleft

109
Q

what is the expanded tip of the axon at the neuromuscular junction

A

synaptic knob

110
Q

what is found inside the synaptic knob

A

synaptic vesicles

111
Q

synaptic vesicles are small __

filled with __

A

membrane sacs

acetylcholine (Ach)

112
Q

the synaptic knob has __ in the plasma membrane

A

calcium pumps

113
Q

the calcium pumps on the synaptic knob plasma membrane establish the calcium __,

wich more calcium __ the neuron

A

establish calcium gradient

outside

114
Q

the synaptic knob also has __ calcium channels, which are opened by

__ signals

A

voltage gated

nerve

115
Q

the synaptic knob has calcium __

and voltage gated calcium __

A

pumps

channels

116
Q

the calcium pump pumps calcium __ its concentration gradient to move calcium

__

A

against

from the inside of the synaptic vesicle

117
Q

how does Ach leave the synaptic vesicle

A

exocytosis

118
Q

what is the specialized region of the sarcolemma covered by the synaptic knob

A

motor end plate

119
Q

what type of receptor does the motor end plate have

A

Ach

120
Q

the synaptic cleft is a narrow __ filled space

that separates the __

and the __

A

fluid

synaptic knob

motor end plate

121
Q

the synaptic cleft contains __ enzyme that breaks down

__ molecules after their release into the synaptic cleft

A

acetylcholinesterase

Ach

122
Q

what is the 1st event of skeletal muscle contraction

A
  1. skeletal muscle excitation
123
Q

what is the 2nd event of skeletal muscle contraction

A

excitation-contraction coupling

124
Q

what is the 3rd event in skeletal muscle contraction

A

binding of Ca2+ and cross-bridge cycling

124
Q

what is the 3rd event in skeletal muscle contraction

A

binding of Ca2+ and cross-bridge cycling

125
Q

what are the 3 steps in skeletal muscle contraction

A
  1. excitation of a skeletal muscle
  2. excitation-contraction coupling
  3. binding of Ca2+ and cross-bridge cycling
126
Q

what are the steps in skeletal muscle relaxation

A
  1. hydrolysis of Ach at receptor (acetylcholinesterase) → closure of receptor channel
  2. no further ap generated
  3. closure of Ca2+ channels in SR
  4. released Ca2+ continuously returned by Ca2+ pumps back into SR
  5. return of troponin to its original shape
  6. tropomyosin now moving over myosin binding sites on actin → prevents cross-bridge formation
  7. returns to original relaxed position thru natural elasticity of muscle fiber
127
Q

how does dantrolene work and what is it used for

A

interferes w. Ca2+ release at SR

spasticity in cerebral palsy, stroke, MS

128
Q

how does succinylcholine (ancetine) work

A

nmj blocking (numbd)

binds Ach receptor at motor endplate insensitive to AchE → maintained depolarization of motor endplate → flaccid skeletal muscle paralysis

129
Q

what is succinylcholine (anectine) used for

A

endotracheal intubation

surgery

mechanical ventilation

130
Q

does succinylcholine have pain relieving properties

A

no!

131
Q

what are the 3 ways ATP is supplied for muscle contraction

A

immediate

short term

long term

132
Q

immediate supply of ATP is called the

A

phosphagen system, 5-6s

133
Q

the immediate/phosphagen system 5-6 is __

and uses (3)

A

anaerobic

available ATP, myokinase, creatinine phosphate

134
Q

the immediate/phosphagen system 5-6 is __

and uses (3)

A

anaerobic

available ATP, myokinase, creatinine phosphate

135
Q

short-term supply of ATP uses __

and is __ cellular respiration

A

glycolysis

anaerobic

136
Q

short term supply of ATP lasts ~

A

50-60 s

137
Q

in short term supply of ATP, __ is stored inside the muscle fiber or delivered by the blood

A

glucose

138
Q

in short term supply of ATP, breakdown of 1 glucose molecule results in production of

A

2 ATP

2 pyruvate

NADH

139
Q

efforts lasting 50-60 s use both __

and __ and result in a

__ debt

A

phosphagen system

glycolysis

oxygen

140
Q

long term ATP supply uses __

and is __ cellular respiration

A

oxidative phosphorylation

aerobic

141
Q

long term supply of ATP is used for efforts lasting

A

greater than 5-6 min

142
Q

long term supply of ATP uses __ produced in glycolysis,

and occurs in the

A

pyruvate

mitochondria

143
Q

long term supply of ATP requires __

and produces __ ATP per glucose

A

oxygen

34

144
Q

skeletal muscle fiber is classified by (2)

A

type of contraction

energy source

144
Q

skeletal muscle fiber is classified by (2)

A

type of contraction

energy source

145
Q

what are the classifications of types of skeletal muscle contraction

A

power

speed

duration of contraction

146
Q

the power of muscle contraction is primarily based on

A

muscle fiber diameter

147
Q

the speed of muscle contraction is determined by

A

slow or fast twitch muscle fibers

148
Q

the duration of muscle contraction is determined by

A

conduction/EC-coupling speed

149
Q

what is the energy source of muscle contraction

A

glycolysis OR oxidative phosphorylation

150
Q

oxidative muscle fibers use __ metabolism and are used for

__ activity

A

aerobic

high endurance

151
Q

oxidative fiber structure consists of (3)

A

extensive capillaries

high # of mitochondria

high concentration of myoglobin

152
Q

what is the source of oxygen for oxidative fibers

A

myoglobin

153
Q

glycolic fibers use __ metabolism and are

easily __

A

anaerobic

fatigued

154
Q

glycolytic fibers have large reserves of

A

glycogen

155
Q

what are the 2 types of muscle contraction

A

isometric

isotonic

156
Q

what type of muscle contraction is insufficient to overcome the load and shows no movement at the joint

A

isometric

157
Q

during isometric contraction, the muscle __ while

tension __, but the

angle of the joint __

A

shortens

increases

does not change

158
Q

what type of muscle contraction is greater than the load

A

isotonic

159
Q

during isotonic contraction, __ remains constant,

but __

and __ change

A

tension

length and joint angle

160
Q

what is concentric contraction

A

isotonic contraction w. muscle length decreasing

161
Q

what is eccentric contraction

A

isotonic contraction w. muscle length increasing

162
Q

what is muscle twitch

A

single, brief contraction in response to a single stimulation of sufficient intensity (voltage)

163
Q

what is threshold

A

minimum voltage necessary to activate a muscle → stimulate a contraction

164
Q

what is the latent period

A

after stimulus is applied, before contraction begins (EPP, CICR, ECC)

165
Q

muscle tension is dependent on (2)

A

intensity

frequency

166
Q

which motor units are activated at threshold

A

only the most sensitive

167
Q

what is all or nothing muscle contraction

A

individual muscle fibers contract (activate) or they do not

168
Q

what determines whether or not a muscle fiber contracts

A

stimuli

169
Q

the force of muscle contraction is determined by

A

of muscle fibers activated

170
Q

increased stimulus intensity (voltage) leads to increased __

and increased

__ until max is achieved

A

of activated motor units

tension

171
Q

muscles can be activated until

A

maximum muscle tension is reached

172
Q

muscle tension is dependent on (2)

A

stimulus intensity

frequency of stimulation

173
Q

given sufficient time for relaxation, developed muscle tension will

A

remain the same for a given stimulus intensity

174
Q

what does treppe describe

A

given sufficient time for relaxation, as frequency increases (same stimulus intensity), muscle tension increases

175
Q

what 3 factors lead to treppe

A
  1. insufficient time for Ca2+ removal by Ca2+ pumps
  2. more cross bridges form w. additional stimulation
  3. increased muscle heat → increased efficiency of molecular interactions
176
Q

what is wave/temporal summation

A

as frequency continues to increased (same stimulus intensity), there is insufficient time for Ca2+ removal, more cross bridge formation, and increased muscle heat BUT time is NOT sufficient for complete relaxation

177
Q

do tetany and rigor have the same mechanism as wave/temporal summation

A

no

178
Q

what are the similarities btw cardiac muscle and skeletal muscle (3)

A

striated

t-tubules

CICR

179
Q

what are the dissimilarities btw skeletal m and cardiac m (4)

A

cardiac m has:

  1. less extensive SR network w. no terminal cisternae
  2. almost entirely aerobic
  3. optimal thick/thin filament overlap during stretch
  4. intercalated discs
180
Q

what % of cardiac m volume is mitochondria

A

25%

181
Q

what are 4 fxn’s of intercalated discs

A
  1. increased stability
  2. increased communication/conduction btw cadiomyocytes
  3. desmosomes at intercalated discs anchor cardiomyocytes together
  4. gap junctions allow for low resistance conduction btw cardiomyocytes
182
Q

what structures prevent the heart from tearing

A

desmosomes

183
Q

what structure allows for syncytium

A

gap junctions

184
Q

where is smooth muscle located (6)

A

blood vessels

respiratory

digestive

urinary

reproductive

specialized: iris of eye, erector pili

185
Q

is smooth m smaller or larger than skeletal m

A

smaller

186
Q

smooth m has only the __ layer,

composed of __

A

endomysium

areolar CT

187
Q

smooth muscles has __ ends

no __,

and limited __

A

tapered

t-tubules

SR

188
Q

how is Ca2+ transport at the SR of smooth m regulated (3)

A

v-gated

chem-gated

modality gated

189
Q

what are 3 examples of modality gated Ca2+ regulation at the SR

A

thermal

stretch hyperglycemia

190
Q

what are the 3 anchoring proteins in smooth m

A

cytoskeleton

dense bodies

dense plaques

191
Q

the cytoskeleton of smooth m is a network of __ filaments

A

intermediate

192
Q

dense bodies are the anchoring sites for __ filaments,

similar to __ disks in skeletal m

A

thin

Z

193
Q

what is the fxn of dense plaques

A

bind the intermediate filaments to the SL

194
Q

what is the contractile mechanism of smooth m

A

contractile proteins

195
Q

where are contractile proteins of smooth m located

A

between dense bodies along the cytoskeleton

196
Q

contractile proteins of smooth m do not have __

or __

A

sarcomeres

z-discs

197
Q

describe the arrangement of the contractile mechanism of smooth m

A

spiral/longitudinal arrangement

198
Q

the spiral/longitudinal arrangement of the contractile mechanism of smooth muscle allows for

A

contraction in multiple directions → twisting

199
Q

smooth muscle contraction

A
200
Q

thick filaments of contractile mechanisms of smooth m have __ along the entire axis

and a __ mechanism that allows

for __

A

myosin

latch

the muscle to stay shortened w.o using additional ATP

201
Q

the thin filaments of smooth muscle have __ (2)

but no __

A

actin, tropomyosin

troponin

202
Q

since the contractile mechanism of smooth muscle does not have troponin, they do not have a

A

Ca2+ binding site

203
Q

without a Ca2+ binding site on the contractile mechanism of smooth m, what brings the myosin hard into binding conformation w. actin

A

the myosin head itself is phosphorylated

204
Q

what completes the phosphorylation of the myosin head in the contractile mechanism of smooth muscle

A

calmodulin

myosin light chain kinase (MLCK)

205
Q

relaxation of smooth muscle occurs via

A

breakdown of MLCK by myosin light chain phosphorylase

206
Q

concentric and eccentric m contractions are subtypes of

A

isotonic contraction

207
Q

example of isotonic contraction

A

10 lb bag of potatoes requires 11 lb of tone to lift → once tension exceeds 10 lb, muscle contracts

208
Q

ex of isometric contraction

A

1,000 lb piano requires 1,001 lb to lift → tension builds but will never reach 1,001 lb → m never contracts

209
Q

factors that increase force of contraction

A

increased:

fiber diameter

fiber length

of active fibers

frequency of stimulation

decreased:

velocity → slower contraction = stronger contraction

210
Q

what is the one decreased factor that increases force of contractin

A

velocity → slower contraction = stronger contraction

211
Q

high-frequency delivery of electrical stimuli causes

A

tetany

212
Q

what is rigor

A

disappearance of ATP from the muscle → actin/myosin filaments unable to detach → filaments become permanently attached

213
Q

which type of m fiber has the smallest diameter

A

slow

214
Q

which type of m fiber is the reddest

A

slow

215
Q

which type of m fiber is the shortest

A

FG

216
Q

which type of muscle fiber is found in upper limbs

A

FG

217
Q

which type of m fiber maintains posture

A

slow

218
Q

oxidative m fibers have high amounts of (3)

A

mitochondria

capillaries

myoglobins

219
Q

smooth m fibers does not have __ (4)

and have limited __

A

do not have:

t-tubules

sarcomere

z disk

troponin

limited:

sarcoplasmic reticulum

220
Q

what facilitates contraction in multiple directions in smooth m

A

spiral/longitudinal arrangement

221
Q

smooth m uses __ for contraction instead of sarcomeres and z disks

A

contractile proteins

222
Q

what is the latch mechanism of smooth m

A

dephosphorylated myosin remains attached to actin → prolonged tonic contraction for hours w. little use of energy → long-term maintenance of tone w.o fatigue

223
Q

what is an example of the latch system of smooth m

A

urinary bladder full of urine

224
Q
A

Pathophys II - Exam 2 (4 decks)

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