Muscles Chapter Flashcards
1
Q
circumduction is
A
ball and socket
2
Q
circumduction is found in how many places
A
2
3
Q
What motion can your axis and occipital condyles do
A
gliding
4
Q
Muscles fibers/cells look like
A
twizzlers(licorice)
5
Q
Strings of twizzlers, single one
A
muscle fiber or muscle cell
6
Q
bundle muscle fibers/cells are covered by and called
A
covered by perimysium, bundle called fascicle
7
Q
my, myo, myology, sarco means
A
muscle
8
Q
A bunch of fascicles are wrapped up in the
A
epimysium
9
Q
epimysium with many bundles of fascicles are
A
muscles
10
Q
what is the extension of the muscle stuck to the bone
A
tendon
11
Q
thin skin that covers whole muscle
A
epimysium
12
Q
smallest functional unit of muscle
A
sarcomere
13
Q
location differences between skeletal, smooth and cardiac muscle.
A
skeleton,
hallow organs/gi tract/blood vessels,
heart.
14
Q
skeletal muscle apperance
A
striations
multinucliated
15
Q
cardiac muscle appearance
A
striations, intercalated discs (vertical lines)
16
Q
smooth muscle appearance
A
no striations
17
Q
Involuntary muscles
A
smooth and cardiac
18
Q
voluntary muscles
A
skeletal
19
Q
functions of muscle tissue
A
motion, posture, stabilization, thermogenesis
20
Q
Motion and muscle tissue
A
external (walking, running, talking and looking) and internal (heartbeat, blood pressure, digestion, elimination) body part movements
21
Q
Thermogenesis and muscle tissue (creation of heat)
A
generating heat by normal contractions and by shivering
22
Q
Muscles are always in a state of
A
partial contraction
23
Q
Posture and muscle tissue
A
slight muscle contraction maintains body posture
24
Q
Stabilization and musc
A
stabilize joints- muscles have tone even at rest
25
When contracting muscles you are always doing what as well
relaxing the opposing force
26
every single muscle in our body has an...
agonist and antagonist
27
an antagonist is there
to stabilize the agonist
28
movement is one of our and how does it have to do with muscle
necessary life functions...
29
Functional characteristics
```
Excitability
Contractility
Extensibility
Elasticity
Conductivity
```
30
Excitability/irritability
the ability to receive and respond to a stimulus (chemical signal molecules)
31
Contractility
ability of muscle tissue to shorten
32
Ability to work in muscle.
Excitability or irritability
33
Extensibility
the ability to be stretched without damage
most muscles are arranged in functionally opposing pairs – as one contracts, the other relaxes, which permits the relaxing muscle to be stretched back
34
Elasticity
the ability to return to its original shape
35
Conductivity (impulse transmission)
the ability to conduct excitation over length of muscle
36
Thin Filaments (Myofibrils – Sarcomeres -Myofilaments)
actin (plus some tropomyosin & troponin)
37
Thick Filaments (Myofibrils – Sarcomeres -Myofilaments)
Myosin
38
Elastic filaments (Myofibrils – Sarcomeres -Myofilaments)
titin (connectin) attaches myosin to the Z discs (very high mol. wt.)
39
Elasticity is only described with what muscles?
Smooth (blood vessels)
40
The ability of a muscle to return back to its shape
elasticity
41
Do you measure elasticity
yes
42
Conductivity relates to
the nervous system and its ability to conduct excitation
43
miogram
measures the conductivity of a muscle
44
ability to spread message across muscle fiber
conductivity
45
sarcomeres are made up of
a lot of protein components
46
Sarcomeres in visual are
overlapping of actin and myosin overlapping the z lines of a muscle fiber contraction
47
Tropomyosin is the what in the story
chasity belt
48
troponin is the what in the story
lock
49
Key to get into the lock
Calcium and Atp
50
The functional unit of striated muscle contraction
Sarcomere
51
The foundation of the muscle cell’s contractile organelle, myofibril
Sarcomere
52
The myofilaments between two adjacent Z discs
| The regular geometric arrangement of the actin and myosin produces the visible banding pattern (striations)
Sarcomere
53
Rod-like tail with two heads
| Tails point to the M line
Myosin
54
Each head contains ATPase and an actin-binding site; point to the Z line
Myosin
55
Splitting ATP releases energy which causes the head to “ratchet” and pull on actin fibers
Myosin
56
Each thick filament contains many myosin units woven together
Myosin
57
Two G actin strands are arranged into helical strands
Actin
58
Each G actin has a binding site for myosin
Actin
59
Two tropomyosin filaments spiral around the actin strands
Actin
60
Troponin regulatory proteins (“switch molecules”) may bind to actin and tropomyosin & have Ca2+ binding sites
Actin
61
what has actin binding sites
myosin
62
what has myosin binding site
actin
63
Triads
2 terminal cisternae + 1 T tubule
64
Sarcoplasmic reticulum (SER):
modified smooth ER, stores Ca2+ ions
65
Terminal cisternae
large flattened sacs of the SER
66
Transverse (T) tubules
: inward folding of the sarcolemma
67
where motor neurons communicate with the muscle fibers
The Neuromuscular Junction:
68
composed of an axon terminal, a synapse and a motor end plate
The Neuromuscular Junction:
69
the end of the motor neuron’s branches (axon)
axon terminal
70
the specialized region of the muscle cell plasma membrane adjacent to the axon terminal
motor end plate
71
Synapse:
point of communication is a small gap
72
Synaptic cleft
the space between axon terminal & motor end plate
73
Synaptic vesicles
membrane-enclosed sacs in the axon terminals containing the neurotransmitter
74
Neurotransmitter:
: the chemical signal molecule that diffuses across the synapse, i.e., acetylcholine, ACh)
75
Acetylcholine (ACh) receptors:
integral membrane proteins which bind ACh
76
Binding of the neurotransmitter (ACh) ... in excitation
Binding of the neurotransmitter (ACh) causes the ligand-gated Na+ channels to open
77
Opening of the Na+ channels.... in excitation
Opening of the Na+ channels depolarizes the sarcolemma (cell membrane)
78
Initial depolarization causes
adjacent voltage-gated Na+ channels to open; Na+ ions flow in, beginning an action potential
79
Action potential
a large transient depolarization of the membrane potential
| transmitted over the entire sarcolemma (and down the T tubules)
80
Repolarization
the return to polarization due to the closing voltage-gated Na+ channels and the opening of voltage gated K+ channels
81
when you hear troponin you think
calcium
82
Where does atp bind to
myosin
83
Refractory period
the time during membrane repolarization when the muscle fiber cannot respond to a new stimulus (a few milliseconds)
84
All-or-none response
once an action potential is initiated it results in a complete contraction of the muscle cell
85
Structure covering all of the muscular fibers
SER
| Sarcoplasmic reticulum
86
What is the job of the SER sarcoplasmic reticulum
to be a storage center for calcium
87
Where does the calcium come from that is stored in SER
Diet
| Parathyroid Horomone breaks down bone for calcium
88
What happens the minute we have an chemical or electrical signal sent to our sarcomere
we open up these gates that are attached to the SER called T (Transverse) Tubules
89
SR opens up the T tubules and sends calcium to
troponin for muscle contraction
90
Crossbridge
myosin/actin getting together
91
The actual binding of the myosin and actin sites is called
powerstroke
92
What two things do you need to have myosin and actin to couple
atp and calcium
93
Whats telling the sarcoplasmic reticulum to release that calcium
the nervous system
94
Acetylcholine
Is a specific neuromuscular joint that sends a signal to muscle to release calcium
95
When you see acetylcholine
Muscle contraction
96
Sarcolema
Membrane of the muscle that is in "contact" with axons of the neuromuscular contractions
97
The way that any cell in our body conducts impulses
is to change the ionic composition
98
The way to change the ionic composition and conduct impulses
3Na 2K pump
99
All acetylcholine doing on the muscle is
opening sodium channels
100
When we open sodium channels we...
are going against the concentration gradient and sending more 3 sodium out and bringing 2 potassium in
101
Depolarization
Send sodium out bringing potassium in
102
Sodium channels open causing
the disruption of whats at rest and that continues to send that impulse or spark all the way down that muscle fiber so it can activate the SER to open and release calcium through the T tubules, attaching to troponin, moving tropomyosin . Then myosin and actin can combine.
103
At rest inside the cell there is more
potassium
104
If the cell isnt at rest then we create an action potential that
goes all the way down to those t tubles
105
What is the neurotransmitter called that sends the message from the nuerons to the muscles?
acetylcholine
106
acetylcholine has do do with
sending nervous systems mesaage to the muscle side
107
Where does the neurotransmitter acetylcholine go?
across the synaptic cleft to its receptor on the muscle cell membrane (sarcolemma)
108
What happens as soon as acetylcholine reaches that recpetor
Opens sodium channels causing to open sodium channels on the muscle side and creates a spark
109
9 volt batteries are like our
cells
110
At rest our cells are at
-70 milivolts
111
Why are our cells at -70 milivolts at rest
because of the concentration of potassium ions on the inside of that cell
112
we have ionic distribution that is what in our cells at all times
uneven
113
At rest on the inside of the cell it is what charge
negative
114
circle K means
at rest K is more in the middle causing it to be negative
115
acetylcholine causes what?
that switch in K being predominant in a cell to Na being predominant
116
When we open up sodium channels with acetylcholine what happens
causes sodium to flow rapidly into the cell making the charge from positive to neg
117
Flipping of the charge in a cell from K- to Na+ is called what
action potential or spark.
118
Depolarization
The opening of sodium channels,, whole wave going through.
119
Repolarization
Going back to rest by opening up K channels,sending more K in. Causing the concentration to equalize
120
Impulse in a cell happens around the
entire membrane
121
All or none response
Charge goes all the way or not at all
122
if only a few sodium channels open what happens
you're not going to produce a strong enough impulse for calcium to diffuse into the cell to attach to troponin so no muscle contraction happens.
123
The action potential (excitation) travels over
the sarcolemma, including T-tubules
124
Voltage sensors on the T-tubules cause corresponding SR receptors to
open gated channels and release Ca2+ ions
125
Excitability is measuring
responded to the nervous system
126
Excitation and coupling both require?
ATP and Ca+
127
Thin and thick filaments slide past each other to
shorten each sarcomere and, thus, each myofibril and shorten the muscle
128
The “on-off switch”: allows myosin
to bind to actin
129
An action potential causes
the release of Ca2+ ions (from the cisternae of the SR)
130
Ca2+ combines with troponin, causing a change in
the position of tropomyosin, allowing actin to bind to myosin and be pulled (“slide”)
131
Ca2+ pumps on the SR remove calcium ions from the sarcoplasm when
the stimulus ends
132
Cross bridge attachment
Myosin heads bind to actin
133
The working stroke.
myosin changes shape (pulls actins toward M line); releases ADP + Pi
134
Cross bridge detachment.
Myosin heads bind to a new ATP; releases actin
135
"Cocking" of the myosin head
ATP is hydrolyzed (split) to ADP + Pi; this provides potential energy for the next stroke
136
The “ratchet action” repeats the process
shortening all the sarcomeres and the myofibrils, until Ca2+ ions are removed from the sarcoplasm or the ATP supply is exhausted
137
The action potential (excitation) travels over
the sarcolemma, including T-tubules
138
Voltage sensors on the T-tubules cause corresponding SR receptors
to open gated channels and release Ca2+ ions
139
Ca2+ binds to troponin, causing tropomyosin
to move out of its blocking position
140
Myosin forms cross bridges to actin, the
power stroke occurs, filaments slide, muscle shortens
141
Calsequestrin and calmodulin help
regulate Ca2+ levels inside muscle cells
142
Acetylcholinesterase: an
enzyme that rapidly breaks down acetylcholine is located in the neuromuscular junction
143
Prevents continuous excitation (generation of more action potentials)
Acetylcholinesterase:
144
Many drugs and diseases interfere with events in the
neuromuscular junction
145
Myasthenia gravis
loss of function at ACh receptors (autoimmune disease?)
146
Curare (poison arrow toxin)
binds irreversibly to and blocks the ACh receptors
147
One power stroke shortens a muscle about
1%
148
Normal muscle contraction shortens a muscle by about
35%
149
cross bridge (ratchet effect) cycle repeats
continue repeating power strokes, continue pulling
| increasing overlap of fibers; Z lines come together
150
How many myosin molecules are attached at any time
about half the myosin molecules
151
Cross bridges are maintained until Ca2+ levels
decrease
152
Ca2+ is released in response to the
the action potential delivered by the motor neuron
153
Ca2+ ATPase pumps Ca2+ ions back into the
SR, using more ATP
154
RIGOR MORTIS
Ca2+ ions leak from SR causing binding of actin and myosin and some contraction of the muscles
155
Rigor Mortis lasts
Lasts ~24 hours, then enzymatic tissue disintegration eliminates it in another 12 hoursq
156
The Motor Unit
Motor Neuron + Muscle Fibers to which it connects (Synapses)
157
The size of Motor Units varies:
Small and large
158
Small motor unit
two muscle fibers/unit (larynx, eyes)
159
large motor unit
hundreds to thousands/unit (biceps, gastrocnemius, lower back muscles)
160
The individual muscle cells/fibers of each motor unit are spread throughout
the muscle for smooth efficient operation of the muscle as a whole
161
Myogram:
a recording of muscle contraction
162
Stimulus:
nerve impulse or electrical charge
163
Twitch:
: a single contraction of all the muscle fibers in a motor unit (one nerve signal)
164
1. latent period:
delay between stimulus and response
165
Myogram stages
1. latent period
2. contraction phase
3. relaxation phase
4. refractory period
166
2. contraction phase:
tension or shortening occurs
167
3. relaxation phase:
relaxation or lengthening
168
refractory period
time interval after excitation when muscle will not respond to a new stimulus
169
All or None Rule:
all the muscle fibers of a motor unit contract all the way when stimulated
170
Contraction force can be altered in 3 ways:
1. changing the frequency of stimulation (temporal summation)
2. changing the stimulus strength (recruitment)
3. changing the muscle’s length
171
Twitch does not provide much
force
172
Force of muscle contraction varies depending on
How much tension is needed
173
sliding filament happens at what level
sarcomere
174
bare zone or m line is for what
to allow for the overlapping of the sarcomere
175
sliding filament theory
m line allowing for overlapping and bringing of the z lines together
176
calcium is the on and off site of the
troponin
177
Power stoke needs what to happen
atp
178
Cocking is also called
the ratchet movement
179
ratchet effect
binding to actin dropping down until we get that overlap together
180
The only way acetylcholine can be broken down is with
acetylcholineesterase
181
acetylcholineesterase does what
take acetylcholine off that receptor thus stoping contractions
182
When would you want to use acetylcholineesterase
muscle relaxer block the receptors of acetylcholine
183
Can you just isolate one muscle when you take a muscle relaxor
acetylcholine
184
myasthenia gravis
autoimmune. loss of function of the acetylcholine receptors. Person has muscle weakness.
185
muscles never push they only
pull
186
muscles are always named based
based on the distal end of the point (the insertion) coming to the origin
187
Contraction is talking about the insertion point of that muscle
coming closer to the origin
188
Rigor mortis explain how
within 24 hrs the binding of calcium on to troponin moving tropomyosin causing actin and mysoin to be stuck together our body stays in state of contraction
189
Rigor mortis doesn't stop until
atp is diffused
190
The entire bicep contracting as one unit is
multiple motor units
191
These motor unit nerves...
branch out to make sure it covers all the muscle fibers throughout any muscle
192
The size of the motor unit depends on
how strong that contraction needs to be
193
Temporal (wave) summation
contractions repeated before complete relaxation, leads to progressively stronger contractions
194
unfused (incomplete) tetanus
frequency of stimulation allows only incomplete relaxation
195
fused (complete) tetanus
frequency of stimulation allows no relaxation
196
Treppe: the staircase effect
“warming up” of a muscle fiber
197
Multiple Motor Unit Recruitment (Summation)
The stimulation of more motor units leads to a more forceful muscle contraction
198
The Size Principle
As greater force is required, the nervous system will stimulate more motor units, and motor units with larger fibers and larger numbers of fibers to achieve the desired strength of contraction.
199
Stretch: Length-Tension Relationship
Stretch (sarcomere length) determines the number of cross bridges
200
extensive overlap of actin with myosin is what tension
less tension
201
optimal overlap of actin with myosin is what tension
most tension
202
Twitch
single contraction of ALL the muscle fibers in one motor unit aka bicep curl
203
Biceps curl is what
one single contraction or twitch
204
Refractory period
you wont be able to repsond to signals saying to conract
205
When you see contraction what is happening
sliding filament shortening and pulling towards each other
206
Depending on the motor unit size affects the
time of the muscle twitch
207
reduced overlap of actin with myosin is what tension
less tension
208
charlie horse or spazam is what kind of summation
unfused incomplete tetanus
209
Summation or production of contractions without allowing it to completely relax will always
intensify that contraction. causing it to become more forceful of a contraction
210
Summation
multiple motor unit recruitment
211
In summation... The more motor units we involve
the more forceful movement or stronger the contraction
212
3 motor units recruited
large fibers
213
Optimal overlap
most cross bridges available for the power stroke and least structural interference
214
Can sarcomeres be different lengths?
yes
215
Optimal length - Lo has what number of cross bridges
maximum number
216
normal working muscle range in optimal length
70 - 130%
217
Isometric Contraction
Muscle does not shorten
| Tension increases
218
Isotonic Contraction:
tension does not change
| Muscle (length) shortens
219
Types of skeletal muscle contractions
isomeric and isotonic contractions
220
Muscle Tone
Regular small contractions caused by spinal reflexes
221
what helps maintain posture
muscle tone
222
where is muscle tone found in the body
e.g., neck, back and leg muscles
223
Muscle tone responds to
Respond to tendon stretch receptor sensory input
224
Muscle tone activates
Activate different motor units over time
225
Muscle tone provides
Provide constant tension development
226
How are the muscles in muscle tone
muscles are firm
| but do not shorten
227
Three ways to replenish ATP:
1. Creatine Phosphate energy storage system
2. Anaerobic Glycolysis -- Lactic Acid system
3. Aerobic Respiration
228
Muscle metabolism energy availability
Not much ATP is available at any given moment
ATP is needed for cross bridges and Ca++ removal
Maintaining ATP levels is vital for continued activity
229
Direct Phosphorylation – Creatine Phosphate System or CrP is stored in
cell
230
Direct Phosphorylation – Creatine Phosphate System Allows for?
atp replenishment
231
How much Direct Phosphorylation – Creatine Phosphate System is avaliable
Only a small amount available (10-30 seconds worth)
232
is O2 required in an anaerobic system
no
233
How efficient is Anaerobic Glycolysis – Lactic Acid System
Very inefficient, does not create much ATP
234
how long is Anaerobic Glycolysis – Lactic Acid System useful
useful in short term situations (30 sec - 1 min)
235
what does Anaerobic Glycolysis – Lactic Acid System produces as a by product
lactic acid
236
Aerobic System uses...
Uses oxygen for ATP production
237
The Oxygen in the aerobic system comes from the
RBCs in the blood and the myoglobin storage depot
238
What substrates does aerobic system use
carbohydrates, lipids, proteins
239
What is aerobic system good for
Good for long term exercise
240
Aerobic system may provide what percentage of ATP needed during these periods
May provide 90-100% of the needed ATP during these periods
241
Oxygen Debt
The amount of oxygen needed to restore muscle tissue (and the body) to the pre-exercise state
242
what must be restored after any vigorous exercise
Muscle O2, ATP, creatine phosphate, and glycogen levels, and a normal pH
243
Circulating lactic acid is converted/recycled back to
glucose by the liver
244
Factors Affecting theForce of Contraction
1. Number of muscle fibers contracting (recruitment)
2. Size of the muscle
3. Frequency of stimulation
4. Degree of muscle stretch when the contraction begins
5. Series elastic elements
245
Series Elastic Elements
All of the noncontractile structures of a muscle:
| internal load and external load
246
All of the noncontractile structures of a muscle:
Connective tissue coverings and tendons
| Elastic elements of sarcomeres
247
Internal load:
force generated by myofibrils on the series elastic elements
248
External load:
force generated by series elastic elements on load
249
Muscle Fiber Type: Speed of Contraction
Slow oxidative fibers
Fast oxidative fibers
Fast glycolytic fibers
250
Slow oxidative fibers
contract slowly, have slow acting myosin ATPases, and are fatigue resistant (red)
251
Fast oxidative fibers
contract quickly, have fast myosin ATPases, and have moderate resistance to fatigue
252
Fast glycolytic fibers
contract quickly, have fast myosin ATPases, and are easily fatigued (white)
253
I-band
- actin filaments,
254
A-band -
myosin filaments which may overlap with actin filaments,
255
H-band -
zone of myosin filaments only (no overlap with actin filaments) within the A-band,
256
Z-line -
zone of apposition of actin filaments belonging to two neighbouring sarcomeres (mediated by a protein called alpha-actinin),
257
M-line -
band of connections between myosin filaments
258
Parallel muscles
Long strap like muscles with parallel fascicles.
259
Convergent muscles
Fascicles that radiate out from a small to wider point of attachment like a blade in a fan.
260
Pennate muscles
Feather like in appearance. Uniquely different types of fascicle attachments that in some ways resemble a old plume pen
261
Fusiform muscles
Fascicles that may be close to parallel in the centre or 'belly' of the muscle but converge to a tendon at one or both ends
262
Spiral muscles
Such as the latissimus dorsi, have fibres that twist between their points of attachment
263
Circular muscles
Often circle body tubes or openings such as the mouth and anus
264
Prime mover
Used to describe a muscle that directly performs a specific movement.
265
Agonist
Same as the prime mover. Directly performs a specific movement
266
Synergists
Are muscles that contract at the same time as the prime movers. They complement prime mover actions so that the prime moves produces a more effective movement
267
Antagonists
Are muscles that when contracting, directly oppose prime movers. They are relaxed while the prime mover is contracting
268
First class lever
Fulcrum lies between the effort and the load
269
Second class lever
Load is in the middle
270
Third class lever
The effort is in the middle
271
What can affect tension
how many fibers are there (myosin and actin crossing over) and size of muscle
272
Fewest cross bridges
more lag space and streched out... less tension
273
When sarcomere is stretched out
less tension reduces overlap
274
More overlapping causes
less tension not optimal for contraction. Cant bring them any closer togther
275
The length of muscle fiber
determines the tension in the muscle
276
Tone or tonicity
muscles being in a slight state of contraction
277
Creatine Phosphate energy storage system
where atp comes from in the muscles
278
Fatigue
no energy loss of atp
279
when we run out of oxygen in order for me to contract we take an alternate pathway we
break down sugar to get ATP anarobic glycolysis
280
byproduct of anarobic glycolysis
lactic acid
281
myglobin is
specifically where the oxygen is stored in the muscle
282
glycolisis is
the breakdown of glycogen
283
distrophin
develops sarcolemma
284
Duchenne Muscular Dystrophy:
Inherited lack of functional gene for formation of a protein, dystrophin, that helps maintain the integrity of the sarcolemma
Onset in early childhood, victims rarely live to adulthood
285
DO...
CHP
8 MOTIONS KNEE SHOUDLDER JOINTS
9 ACTIONS AND GROUPS
10 CHART UNDER LAB
286
Muscle tissue develops from
Cembryonic mesoderm called myoblasts (except the muscles of the iris of the eye and the arrector pili muscles in the skin)
287
Multinucleated skeletal muscles form by
fusion of myoblasts
288
With age, connective tissue _____ and muscle fibers_____
increase
| decrease
289
When older muscles become
Muscles become stringier and more sinewy
290
By age 80, how much muscle mass is lost (sarcopenia)
50%
291
What reverses scrapopenia
regular exercise
292
Body strength per unit muscle mass, however, is the
same in both sexes
293
Atherosclerosis may
block distal arteries, leading to intermittent claudication and causing severe pain in leg muscles
294
Men’s skeletal muscle makes up
42% of body mass
295
Women’s skeletal muscle makes up
36% of their body mass
296
Muscular development reflects
neuromuscular coordination
297
Athletics and training can improve
neuromuscular control
298
Satellite (stem) cells can
fuse to form new skeletal muscle fibers
299
Smooth muscle has good
regenerative ability
300
Cardiac cells lack
satellite cells
301
Cardiac and smooth muscle myoblasts do not
not fuse but develop gap junctions at an early embryonic stage
302
Multinucleated skeletal muscles form by
fusion of myoblasts
303
The growth factor agrin stimulates the clustering of ACh
receptors at newly forming motor end plates
