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
2
Q
____ muscle is
- striated
- found in heart
- involuntary, autonomic nervous, hormones
A
Cardiac
3
Q
____ muscle is
- striated
- voluntary, learned patterns of movement
A
Skeletal
4
Q
Which muscle is attached to skin and bones?
A
Skeletal
5
Q
Is cardiac muscle only found in the heart?
A
Yeah, duh
6
Q
Is cardiac muscle striated?
A
Yes
7
Q
Is cardiac muscle involuntary?
A
Yes
8
Q
Is smooth muscle striated?
A
NO
9
Q
Is smooth muscle voluntary?
A
No
10
Q
Is smooth muscle tissue found in the walls of hollow organs?
A
Yes
11
Q
Excitability is the ability to ____ and ____ to stimuli
A
receive and respond
12
Q
Contractility is the ability to ____ when stimulated
A
shorten
13
Q
Extensibility is the ability to be ______
A
Stretched
14
Q
Elasticity is the ability to ____ to resting length
A
Recoil
15
Q
In skeletal muscle structures, ______ is dense irregular connective tissue surrounding the entire skeletal muscle
A
Epimysium
16
Q
In skeletal muscle structures, ______ is dense irregular connective tissue surrounding muscle fasciculi
A
Perimysium
17
Q
In skeletal muscle structures, ______ is loose areolar connective tissue surrounding muscle fibers
A
Endomysium
18
Q
Which skeletal muscle structure surrounds the entire skeletal muscle?
A
Epimysium
19
Q
Which skeletal structure surrounds the muscle fasciculi?
A
Perimysium
20
Q
which skeletal structure surrounds the muscle fibers?
A
Endomysium
21
Q
Muscles attach directly and ______
A
indirectly
22
Q
Muscles attach directly, ______ of muscle is fused to the Periosteum of bone
A
Epimysium
23
Q
Muscles attach indirectly, connective tissue wrappings extend beyond the muscle as rope like _____
A
tendon
24
Q
Which is more common, muscles that attach directly or indirectly?
A
Indirectly
25
Directly or indirectly? "epimysium of muscle is fused to the periosteum of bone"
Directly
26
Dir or indirectly? "connective tissue wrappings extend beyond the muscle as a roselike tendon"
Indirectly
27
In direct muscle attachment, the epimysium of the muscle is fused to which part of the bone?
The periosteum of the bone
28
In indirect attachment of muscles, connective tissue wrappings extend beyond the muscle as rope like ______.
Tendon
29
Does skeletal muscle have multiple nuclei?
Yes
30
Does skeletal muscle have many mitochondria?
Yes
31
_______ muscle contains myofibrils, sarcoplasmic reticulum, and T-tubules.
Skeletal
32
Does skeletal muscle contain glycosomes?
Yes
33
In skeletal muscle, glycosomes is used to store glycogen. True or false?
True
34
What are densely packed, rodlike elements? Myofibrils or t-tubules?
Myofibrils
35
Do myofibrils exhibit striations?
Yes
36
______ have perfectly aligned repeating series of dark _ bands and light _ bands
Myofibrils have perfectly aligned repeating series of dark A bands and light I bands
37
_____ : A protein fiber network which forms attachment sites for actin myofilamints
Z-disk
38
____: Consists of actin (thin filaments) which spans each z disk and ends at the myosin myofilaments
I band (light)
39
____: extends the length of the myosin myofilaments (thick filaments)
A band (dark)
40
____: Filaments do not overlap
H zone
41
____: consists of protein myomesin which holds the thick filaments together
M line
42
What is the smallest contractile unit of a muscle fiber?
Sarcomere
43
_____ is the region of a myofibril between two successful z discs
Sarcomere
44
_____ are composed of thick and thin myofilaments made of contractile proteins
Sarcomere
45
In a sarcomere, is myosin a thick or thin filament?
Thick
46
In a sarcomere, is actin a thick or thin filament?
Thin
47
In a sarcomere, is troponin a thick or thin filament?
thin
48
In a sarcomere, is tropomyosin a thick or thin filament?
thin
49
In a sarcomere, is Titin a structural protein?
Yes
50
In a sarcomere, is M-line a structural protein?
Yes
51
In a sarcomere, is a z-disk a structural protein?
Yes
52
_____, ______, and _____ are structural proteins of a sarcomere
Titan, M-line, and z-disk
53
______ is a contractile protein in thick filament
Myosin
54
______ is a contractile protein in thin filament
Actin
55
______ is a regulatory protein in thin filament (binds calcium)
Troponin
56
______ is a regulatory protein in thin filament
Tropomyosin
57
______ is a structural protein; stretching (springs)
Titin
58
______ is a structural protein (M-LINE) anchors myosin
Myomesin
59
Which muscle protein anchors myosin?
Myomesin
60
______ is a structural protein that anchors actin
Z-disk
61
Which muscle protein anchors actin?
Z-disks
62
Which muscle protein binds calcium?
Troponin
63
Which muscle protein is found in thick filament, myosin or actin?
Myosin
64
Which muscle protein is found in thin filament, Myosin or actin?
Actin
65
Does tropomyosin bind calcium?
No, troponin does
66
Which muscle protein stretches?
Titin
67
The ultrastructure of Thick Filament is composed of Myosin ______ and ______
heads and tails
68
In the ultrastructure of thick filament, the myosin tails contain two interwoven, heavy ______ chains
Polypeptide
69
Do myosin tails contain interwoven polypeptide tails?
Yes
70
in the ultrastructure of thick filament, myosin heads contain 2 smaller, light ______ chains that act as cross bridges during ________
Polypeptide, during contraction.
71
What is the binding sites for actin of thin filaments, the myosin heads or tails?
Heads
72
What is the binding site for ATP, myosin tails or heads?
heads
73
ATPase enzymes occur at myosin _____
heads
74
Thick filament is composed of the protein _______
Myosin
75
What are myosin tails composed of in the thick filament?
2 interwoven, heavy polypeptide chains
76
______:
-act as cross bridges during contraction
binding sites for ATP
ATPase enzymes
Myosin heads
77
In the ultrastructure of thin filament, twisted double strands of fibrous protein are called ____
F actin (fibrous actin)
78
In the ultrastructure of thin filament, F actin consists of ______ subunits
G actin (globular)
79
In the ultrastructure of thin filament, G actin bears active sites for ____ ____ attachment during contraction
myosin head
80
In the ultrastructure of thin filament ______ and _____ are regulatory proteins bound to actin
Tropomyosin and troponin
81
"Twisted double strand of fibrous protein: F actin" Thick or thin filament?
Thin
82
"f actin consists of g actin subunits" Thick or thin?
thin
83
During contraction, which actin bears active sites for myosin head attachment?
G-Actin
84
Which two regulatory proteins bind to actin?
Tropomyosin and troponin
85
_____: the generation of force
Contraction
86
______ does not necessarily cause shortening of the fiber
Contraction
87
In a contraction, shortening occurs when tension generated by ____ ____ on the _____(thick or thin?) filaments exceeds forces opposing shortening
cross bridges; thin
88
Do contractions always cause shortening of the fiber?
No
89
during contraction, myosin _____ bind to actin, detach, and bind again, to propel _____ filaments towards the ___line.
heads; thin; M
90
During contractions, do myosin heads propel towards the M line after binding to actin, detaching, and then binding again?
yes
91
Tropomyosin blocks the active sites on actin when....
you have low intracellular Ca2+
92
Myosin heads cannot attach to actin when.....
you have low intracellular Ca2+
93
Muscle fiber relaxes when....
you have low intracellular Ca2+
94
Ca2+ binds to troponin when you have.....
high intracellular Ca2+ concentrations
95
Troponin changes shape and moves tropomyosin away from active sites when you have...
high intracellular Ca2+ concentrations
96
At high intracellular Ca2+ concentrations, events of the ___ ____ ___ occur
Cross bridge cycle
97
When nervous stimulation ceases, ______ is pumped back into the SR and contraction ends
Ca+2
98
Ca2+ is pumped back into the SR and contraction ends when....
nervous stimulation ceases
99
Ca2+ is pumped back into the SR and contraction ends at high concentrations of
Ca+2
100
For the cross bridge cycle to continue, a Ca2+ ____ and adequate _____ must be present
signal; ATP
101
In cross bridge formation, high energy myosin ____ attaches to _____ filament
Heads attach to thin filament
102
Working (power) stroke in the cross bridge cycle occurs when the myosin _____ pivots and pulls thin filament toward the ____ line
Myosin head pivots and pulls thin filament toward the M Line
103
In the cross bridge cycle, ATP attaches to myosin heads and the cross bridge detaches. This is called _____ ____ ___
Cross Bridge detachment
104
In the cross bridge cycle, energy from hydrolysis of ATP cocks the myosin head into the high-energy state. This is called _____ of the ____ ____
Cocking of the myosin head
105
The _____ ____ is a network of smooth endoplasmic reticulum surrounding each myofibril
Sarcoplasmic Reticulum (SR)
106
The _____ _____ has pairs of terminal cisternae that form perpendicular cross channels
Sarcoplasmic Reticulum
107
The _____ _____ functions in the regulation of intracellular Ca2+ levels
Sarcoplasmic reticulum
108
What is the function of the SR?
Regulation of intracellular ca2+ levels
109
The SR is a network of smooth endoplasmic reticulum surrounding each _______
Myofibril
110
The SR has pairs of terminal ______ that form perpendicular ____ ____
cisternae; cross channels
111
_ _______ are continuous with the sarcolemma
T Tubules
112
_ ________ associate with the paired terminal cisternae of sarcoplasmic reticulum to form triads that encircle each sarocmere
T Tubules
113
T tubules associate with the paired _____ _____ of the ______ _____
terminal cisternae; sarcoplasmic reticulum
114
What associates with the paired terminal cisternae?
T Tubules
115
__ _____ conduct impulses deep into muscle fiber
T Tubules
116
____ _____ protrude into the inter membrane space from T tubule and SR cisternae membranes
Integral proteins
117
__ ____ ____ are gated channels that regulate Ca2+ release from the SR cisternae
SR foot proteins
118
What conducts impulses deep into muscle fiber?
T tubules
119
What protrudes into the inter membrane space from T tubule and SR cisternae membranes?
Integral Proteins
120
SR foot proteins are gated channels that regulate ____ release from the SR _______
Ca2+; Cisternae
121
Integral proteins protrude into the inter membrane space from ______ and ___ _____ membranes
T tubules and SR cisternae
122
What are the two requirements for skeletal muscle contraction?
Activation and excitation-contraction coupling
123
_____ is neural stimulation at a neuromuscular junction
Activation
124
______-_______ _____ is a generation and propagation of an action potential along the sarcolemma
Excitation-contraction coupling
125
____-____ ____ has a final trigger, which is a brief rise in intracellular ca2+ levels
Excitation contraction coupling
126
What is the final trigger in the excitation-contraction coupling?
A brief rise in intracellular ca2+ levels
127
A requirement for skeletal muscle contraction is activation, which is a ____ _____ at a neuromuscular junction
neural stimulation
128
Skeletal muscles are stimulated by somatic ____ _____
motor neurons
129
Axons of motor neurons travel from the ____ ____ _____ via nerves to _____ _____
central nervous system; skeletal muscles
130
Each ____ ending forms a ____ _____ with a single muscle fiber
Each axon ending forms a neuromuscular junction with a single muscle fiber
131
What are skeletal muscles stimulated by?
Somatic motor neurons
132
A neuromuscular junction is situated midway along the length of a ____ ____
muscle fiber
133
Axon terminal and muscle fiber are separated by a gel-filled space called the _____ _____
synaptic cleft
134
Synaptic vesicles of axon terminals containing the neurotransmitter ______ (ACh)
Acetylcholine
135
Junctional folds of the sarcolemma contain _____ receptors
ACh
136
What is the synaptic cleft?
Gel-filled space
137
Which enzyme quickly terminates ACh?
Acetylcholinesterase
138
The destruction of ACh prevents continued ____ ____ ___ in the absence of additional stimulation
muscle fiber contraction
139
Resting cell membrane potential is also called _______
Polarization
140
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 ________
Polarized
141
To depolarize a cell, there must be simultaneous diffusion of _____ inward and _____ outward
Na+ and K+
142
The interior of the sarcolemma becomes less negative the more _____ diffuses
Na+
143
End plate potential is when ____ _____ occurs
local depolarization
144
One event in the generation of an action potential, end plate potential spreads to ____ ____ areas
adjacent membrane
145
Do voltage-gates Na+ channels need to open to generate action potential?
Yes
146
Does the Na+ influx decrease the membrane voltage toward a critical threshold?
Yes
147
When can action potential finally be reached?
When the threshold is reached
148
Local ______ waves continue to spread, changing the permeability of the sarcolemma.
depolarization
149
Voltage-regulated Na+ channels open in the ____ ____, causing it to depolarize to threshold
Adjacent patch
150
To repolarize, ____ channels close and voltage-gated _____ channels open
Na+ ; K+
151
_____ efflux rapidly restores the resting polarity
K+
152
Fiber cannot be stimulated and is in a _____ period until repolarization is complete
refractory
153
ionic conditions of the resting state are restored by the _______ pump
Na+-K+ pump
154
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
1. action potential
2. T Tubules
3. Ca++ from sarcoplasmic reticulum
4. Ca++ binds with troponin releasing the myosin binding sites
155
AP id propagated along the _____ to the T-tubules
Sarcomere
156
What is necessary for contraction, CA2+ or vitamin D?
Ca2+
157
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?
Low levels
158
At higher intracellular levels of Ca2+, calcium binds to _____
Troponin
159
After ca2+ binds to troponin, it changes shape and moves the ____ away from the active sites
Tropomyosin
160
When the tropomyosin has been moved away from the active sites, the ____ ____ cycle occurs
Cross bridge
161
When the stimulation ceases, Ca2+ is pumped back into the _____ _____ and contraction ends
Sarcoplasmic reticulum
162
In an _____ ______, no shortening; muscle tension increases but does not exceed the load
Isometric contraction
163
In an ______ _____, muscle shortens because muscle tension exceeds the load
Isotonic contraction
164
In an isometric contraction there is no ______, the muscle tension increases but ___ ___ exceed the load
shortening; does not
165
In an isotonic contraction, the muscle shortens because....?
because the muscle tension exceeds the load
166
A ____ ____ is a motor neuron and all muscle fibers it supplies
Motor unit
167
A motor unit is a motor neuron and all ___ ____ it supplies
muscle fibers
168
_____ motor units are in muscles that control fine movements (fingers, eyes)
Small
169
_____ motor units in large weight-bearing muscles
Large
170
Are muscle fibers in a motor unit spread throughout the muscle?
Yes
171
Why are muscle fibers within a motor unit spread throughout the muscle?
SO that a single motor unit causes weak contraction of an entire muscle
172
Motor units in a muscle contract _______, which helps prevent fatigue
asynchronously
173
What do motor units do to prevent fatigue?
They contract asynchronously
174
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
1. Latent Period
2. period of contraction
3. Period of relaxation
175
The three phases of a twitch include the latent period, which are the vents of ____ -_____ coupling
Excitation-contraction
176
The three phases of contraction includes the period of contraction. This period is the ___ ____ formation, and tension increases
Cross bridge
177
The period of relaxation, one of the three twitch phases, is when ____ reenters the SR and tension declines to 0
Ca2+
178
Graded muscle responses are graded by
| 1. Changing the ______ of the ______
frequency of stimulation
179
Graded muscle responses are graded by
| 2. Changing the _____ of the ______
strength of the stimulus
180
Further increase in stimulus frequency results in ____ tetanus
unfused
181
During a change in stimulus frequency, a Ca2+ release stimulates further contraction, and is called _____ _____
temporal summation
182
___ _____ : stimulus strength at which the first observable muscle contraction occurs
Threshold stimulus
183
Isotonic contractions are either _____ or _____
Concentric or eccentric
184
_____ contractions: the muscle shortens and does work
concentric
185
____ contractions: The muscle contracts as it lengthens
Eccentric
186
___ Is the only source used directly for contractile activities
ATP
187
Available stores of ATP are depleted in ___ to ___ seconds
4 to 6
188
ATP is regenerated by direct _____ of ADP by _____ phosphate
phosphorylation of ADP by creatine phosphate
189
ATP is regenerated by _____ which is an ______ pathway
Glycolysis; anaerobic
190
ATP is regenerated by ______ respiration
aerobic
191
Creatine phosphate stores ____ seconds of ATP
15
192
Anaerobic respiration is also called:
II A
193
Creatine phosphate is also called:
II B
194
Aerobic respiration is also called
I
195
Anaerobic respiration requires Glucose -> _ lactic acid and _ ATP
2 and 2
196
aerobic respiration is limited by?
Gas exchange
197
Aerobic respiration: myoglobin stores ____
oxygen
198
Anaerobic respiration has ___ to ___ seconds of activity
30 to 40
199
___ ___ buildup occurs during anaerobic respiration
Lactic acid
200
Oxygen delivery is impaired with the _____ pathway
Anaerobic
201
____ acid is converted into ____ acid in the anaerobic pathway
Pyruvic; lactic
202
___ ___ diffuses into the blood stream
Lactic acid
203
___ ___ is used as fuel by the liver, kidneys, and heart
Lactic Acid
204
___ ___ is converted back into pyruvic acid by the _____
lactic acid; liver
205
____ pathway produces 95% of ____ during rest and light to moderate exercise
aerobic pathway; ATP
206
The ____ pathway stores _____, then bloodborne glucose, ____ acid from glycolysis, and free fatty acids
Aerobic; glycogen; pyruvic acid.
207
Which pathway stored free fatty acids?
Aerobic
208
Force of contraction is affected by: _____ and the relative size of _____
Recruitment; size of fibers
209
Hypertrophy of cells increases _____
strength
210
THe number of muscle fibers stimulated is also known as _____
recruitment
211
Speed of contraction is controlled by the speed at which _____ ATPases split ____
myosin; ATP
212
Speed of contractions is controlled by the pattern of electrical activity of the ____ ____
motor neurons
213
Oxidative fibers use ____ pathways
aerobic
214
Glycolytic fibers use ____ glycolysis
anaerobic
215
Slow oxydative fibers are also called:
Type I
216
Fast oxydative fibers are called
Type II A
217
Fast glycolytic fibers are called
Type II B
218
"Thin, aerobic, slow twitch, many capillaries, myoglobin Resistant to fatigue" This is? (type I)
Slow oxydative fibers
219
"Medium thickness, aerobic, fast twitch,
many capillaries, myoglobin, high glycogen
Moderate resistant to fatigue
"This is? (Type IIA)
Fast oxydative fibers
220
"Very thick, anaerobic, fast, powerful twitch,
high glycogen, few capillaries and myoglobin
Fatigues easily
" This is? (Type II B)
Fast glycolytic fibers
221
Are slow, oxydative fibers thick?
No, they are thin and aerobic.
222
Are slow oxydative fibers resistant to fatigue?
Yes
223
Are slow oxydative fibers also named Type II B?
No, they are type I
224
Fast oxydative fibers have medium thickness, aerobic, and result in fast twitches. true or false?
True
225
Do fast oxydative fibers have a moderate resistance to fatigue?
Yes
226
Do fast oxidate fibers lack capillaries?
No, they have many
227
Do all three types of muscle fibers have myoglobin?
Yes
228
Do fast glycolytic fibers fatigue easily?
Yes
229
Which muscle fiber fatigues easily? Which one is very resistant to fatigue?
Type II B(fast glycol) and Slow oxydative (type I)
230
Name the muscle fibers from thickest to thinnest.
Fast glycolytic
fast oxy
slow oxy
231
Name the two layers of smooth muscle
Longitudinal and circular
232
Where is smooth muscle found?
Walls of most hollow organs
233
______ is the alternating contractions and relaxations of smooth muscle layers
Peristalsis
234
When _____ layer of smooth muscle contracts, the organ dilates and shortens
Longitudinal
235
when ______ layer of smooth muscle contracts, the organ constricts and elongates
Circular
236
This describes which microscopic structure of smooth muscle? "thin and short compared with skeletal muscle fibers
"
Spindle-shaped fibers
237
In smooth muscle, ____ ____ is only found in the endomysium
Connective tissue
238
In smooth muscle, the _____ _____ is less developed than in skeletal muscle
Sarcoplasmic reticulum
239
Pouch like inholdings (caveolae) of the sarcolemma sequester Ca2+. This describes which microscopic type of muscle?
Smooth
240
Does smooth muscle contain sarcomeres, myofibrils or T tubules?
No
241
_____ _____ ___ innervate smooth muscle at diffuse junctions
Autonomic nerve fibers
242
_______ of nerve fibers store and release neurotransmitters
Varicosities
243
In skeletal muscle, the ratio of thick to thin filaments is 1:2. In smooth muscles, it is what?
1:13
244
Thick filaments have heads along their entire length in which type of muscle?
Smooth
245
Troponin in skeletal muscle binds to calcium. However, in smooth muscle, the protein _____ binds calcium
Calmodulin
246
How are myofilaments in smooth muscle arranges?
Spirally
247
Because myofilaments in smooth muscle are spirally arranged, this causes smooth muscle to contract in what type of manner?
A corkscrew manner
248
Smooth muscle has ____ bodies
Dense
249
Smooth muscle has dense bodies: proteins that anchor non contractile intermediate filaments to _____ at regular intervals
Sarcolemma
250
Smooth muscle has slow, _______ contractions
Synchronized
251
Some smooth muscle cells are self_______
excitatory
252
Some smooth muscle cells are self-excitatory, which means they ______ without external stimuli
depolarize
253
______ and _____ stimuli may modify the rate and intensity of a smooth muscle contraction
Neural and chemical
254
In smooth muscle, Ca2+ binds to and activates _______
Calmodulin
255
In smooth muscle, activates calmodulin activates _____ kinase
myosin
256
In smooth muscle, activated kinase _______ and activates myosin
phosphorylates
257
After the activates kinase phosphorylates and activates myosin, the ____ ____ interact with actin
Cross bridges
258
Are the contractions of smooth muscle energy efficient?
Yes
259
in smooth muscle, Myofilaments may maintain a latch state for prolonged ______
contractions
260
Relaxation of smooth muscle requires that ____ detaches from the calmodulin
Ca2+
261
Relaxation of smooth muscle contractions requires active transport of Ca2+ into the _____ _____
sarcoplasmic reticulum
262
Relaxation of smooth muscle contractions requires the dephosphorylation of _____ to reduce ATPase activity
myosin
263
Multiunit smooth muscle is located in large airways. True or false?
True
264
which type of smooth muscle is found in arrector pili muscles?
Multiunit
265
Are gap junctions rare in multiunit smooth muscle?
Yes
266
How is multiunit smooth muscle arranged?
In motor units
267
Do large arteries contain multiunit skeletal muscle?
No, they contain multiunit smooth muscle
268
____ _____ occur in response to neural stimuli (smooth multiunit muscle)
Graded contractions
