Quiz 2 Flashcards
1
Q
What is the neuromuscular junction
A
the place where the motor neuron connects to the muscle
2
Q
What is the shape of the neuromuscular junction
A
it looks like the outline of a rake
3
Q
What is the ACH receptor
A
Ligand gated Na channel
4
Q
What binds to the ACH receptor
A
acetylcholine (ACH)
5
Q
What is the Na channel
A
a voltage gated Na channel
6
Q
What is acetylcholinesterase
A
An enzyme that breaks down ACH in the neuromuscular junction
7
Q
What is the process that happens at the neuromuscular junction
A
- Depolarization of the motor neuron reaches the neuron terminal
- This causes a Ca channel to open up
- the Ca stimulates the release of ACH
- ACH enters the neuromuscular junction
- It binds to the ACH receptor, opening the Na channel
- That causes the voltage gated Na channel to open
- that causes the muscle to depolarize
- The Acetycholinesterase breaks down the remaining ACH to prevents continuous contraction
8
Q
Where in the neuromuscular junction are all the things found
A
- ACH receptor top of the peaks
- Voltage gated Na channel midway up the peaks
- Acetylcholinesterase bottom of the pits
9
Q
What is the name of the place in the neuromuscular junction where all these things are found
A
Motor end plate
10
Q
what are the parts of the motor end plate
A
primary cleft
secondary cleft
11
Q
What is the primary cleft
A
the place above the ridges, where the ACH is released
12
Q
what is the secondary cleft
A
the place in the motor end plate where all of the channels and enzymes are, hills and valleys
13
Q
What is the sarcoplasmic reticulum
A
a network of tubing that surrounds every myofibril. Has terminal cisternae near the T-Tubules
14
Q
What is found in the sarcoplasmic reticulum
A
Calcium
15
Q
what is found on the membrane of the sarcoplasmic reticulum
A
SERCA pumps
16
Q
What does the Serca pump do
A
pumps calcium back into the sarcoplasmic reticulum from the sarcaplasm
17
Q
What is the function of the terminal cisternae
A
it holds the majority of calcium in the sarcoplasmic reticulum, and it is associated with the T-tubules.
18
Q
What is the t-tubule
A
an opening in the sarcolemma that goes through the whole cell and exits on the other side. it transmits the depolarization of the cell down to each myofibril
19
Q
How are the t-tubules associated with muscle fatigue
A
I don’t know
20
Q
What is the DHP
A
a protein in the t-tubule membrane that changes conformation when depolarization gets to it.
Associated with the Ryanodine receptor in the Sarcoplasmic reticulum
21
Q
What is the ryanodine receptor
A
a calcium channel in the sarcoplasmic reticulum that is associated with DHP
22
Q
What happens to DHP/Ryanodine when the t-tubule is depolarized
A
DHP pulls on ryanodine, causing it to open, allowing calclium to leave the Sarcoplasmic reticulum
23
Q
What are the steps in excitation contraction coupling
A
- Depolarization of the motor neuron reaches the neuron terminal
- This causes a Ca channel to open up
- the Ca stimulates the release of ACH
- ACH enters the neuromuscular junction
- It binds to the ACH receptor, opening the Na channel
- That causes the voltage gated Na channel to open
- that causes the muscle membrane to depolarize
- The Acetycholinesterase breaks down the remaining ACH to prevents continuous contraction
- The depolarization of the muscle membrane travels all over the cell and down the t-tubule
- in the t-tubule the DHP protein changes conformation pulling on the ryanodine protein in the terminal cisternae
- The opening of the ryanodine channel allows Ca to exit the Sarcoplamic reticulum
- the calcium binds to troponin
- Troponin and tropomyosin are pulled off of the myosin binding sites
- myosin binds to actin, and a powerstroke occurs
- ATP binds to the myosin head causing it to release from actin
- ATPase breaks down the ATP causing it to cock back
- This process continues until the calcium is pumped back out of the sarcoplasm by SERCA pumps.
24
Q
how are muscle tissue samples collected
A
bergstrom biopsy needles
25
What are the two types of muscle fiber type properties
1. biochemical properties
| 2. Contractile propoerties
26
what are the biochemical properties of muscle fiber types
1. oxidative capacities
| 2. ATPase type
27
What are the things that determine oxidative capacities
Mitochondria
capillaries
myoglobin
28
What are the types of ATPase
Slow and fast
29
What are the 2 contractile porperties
1. Maximal force production
| 2. Velocity of contraction
30
What are the two things that influence muscle force production
1. peak tension
| 2. fiber CSA
31
what are the things that influence the velocities of contraction
1. Twitch characteristics
2. ATPase isoform
3. MHC isoform
32
What are the three types of muscle fibers
Type 1
Type 2a
Type 2x
33
What is the order of fiber types from slowest to fastest
Type 1
Type 2a
Type 2x
34
how many neuromuscular junctions are there per muscle fiber
1
35
Where do the terminal cisternae sit in relation to the sarcomere
where the A band is, because that's where the calcium is needed
36
how common are satellite cells in muscle
very common 200-300 per mm
37
what do satellite cells hold
all the genetic info for the muscle cells
38
is muscular dystrophy more common in men or women
men
39
what gets together to for the thick filament
the tail regions of myosin 2
40
how well are the thick/thin filaments organized
very very well
41
What does CIT stand for
the functions of troponin
C - calcium binding
I - Inhibits myosin binding site
T - associated with tropomyosin
42
How can MHC and ATPases differ from one muscle cell to another
they can be fast or slow.
Fast MHC = fast powerstrokes
Fast ATPase = Fast relleasing and cocking
43
What percent of ryanodine receptors are bound to DHP
about 50%
44
what happens with the ryanodine receptors that aren't bound to DHP
they are activated by the calcium let out by the others.
45
How are muscle cells named
1. Twitch velocity
2. Energy production
3. ATPase/MHC type
46
What are the three different kinds of muscle cells
1. Fast, glycolitic, IIx
2. Slow, Oxidative, I
3. Medium, Glycolitic/oxidative, IIa
47
what is the length of a sarcomere
2.5 micrometers
48
What are the 5 characteristics upon which muscle cell type is determined
1. # of mitochondria
2. Resistance to fatigue
3. Predominant energy system
4. ATPase activity
5. Speed of shortening
49
What are the 5 characteristics of type IIx muscle fibers
1. Low mitochondria
2. Low resistance to fatigue
3. Anaerobic energy system (glycolytic)
4. Highest ATPase activity
5. Highest speed of shortening
50
What are the 5 charateristics of type IIa muscle fibers
1. Moderate amounts of mitochondria
2. Moderate resistance to fatigue
3. Combination of Oxidative/Glycolitic energy system
4. High ATPase activity
5. Intermediate speed of shortening
51
What are the 5 charateristics of type I muscle fibers
1. HIgh amounts of mitochondria
2. High resistance to fatigue
3. Aerobic energy system (oxidative)
4. Low ATPase activity
5. Low speed of shortening
52
What are the different ways to do muscle typing
1. Myosin ATPase typing
2. MHC composition
3. Single fiber analysis
53
How is Myosin ATPase typing done
1. get a frozen tissue sample
2. cut really thin slices
3. use a histochemical enzyme stain
- This binds to the type of ATPase
4. Darkest to lightest = type I - IIa - IIx
5. count total number of fibers, and number in each category to figure out muscles fiber type percentage
54
What are the pros/cons Myosin ATPase typing
1. Small sample size for the whole muscle to be determined by
2. Subjective analysis, hard for researches to decide between fiber types sometimes
3. General
55
How does MHC composition typing work
1. Get muscle sample
2. blend it up into a fluid mixture
3. place mixture in a gel electrophoresis machine
4. Look and what bands are present
- Lowest to highest, type I - IIa - IIx
5. Use a pixelometer to see how dense each line is and thereby determine fiber type percentages
56
What are the benefits/downfalls to this method
1. More objective than ATPase typing
| 2. Still very general
57
How does single fiber analysis work
1. Isolate one muscle fiber
2. blend it up and run a gel electrophoresis
3. Look at it's bands
- Lowest to highest, Type I - IIa - IIx
58
What are the pros/cons of single fiber analysis
1. Allows you to visualize hybrid muscle fiber types
2. more objective
3. Takes a lot of time
59
What are the most common hybridizations in muscle fibers
I - IIa, and IIa - IIx
60
Really can you classify a single muscle cell in only one category
no they just fit somewhere along the muscle fiber continuum
61
What happens to hybridized muscle fibers as you train
they go away
62
What percent of muscle cells and hybridized in untrained individuals
30%
63
Do fiber types in individuals change when they train in different domains
yep
64
What types of fibers do sprinters have
more fast muscle fiber types than the average person
65
What types of fibers do endurance athletes have
more slow muscle fibers than the average person
66
What types of fibers do weight lifters and non-atheletes have
about 50-50 fast and slow
67
What are the general functions of the nervous system
1. Control of the internal environment (works with the endocrine system)
2. Voluntary control of movement
3. Programming spinal cord reflexes
4. Assimilation of experiences necessary for memory and learning
68
What is the organization of the Nervous system
1. CNS - brain and spinal cord
| 2. PNS - All Nerves not inside CNS
69
What are the branches of the PNS
Afferent and Efferent
70
What is an afferent nerve
a nerve that runs to the CNS
71
What is an efferent nerve
a nerve that runs from the CNS
72
What kind of nerves make up afferent nerves
1. Somatic sensory
2. Visceral sensory
3. Special sensory
73
What kind of nerves make up efferent nerves
1. Somatic Motor
2. Autonomic motor
- Sympathetic
- Parasympathetic
- Enteric
74
What parts of the Nervous system are voluntary, which parts are involuntary
voluntary is somatic nervous system
| Everything else is involuntary
75
How does the PNS work with the CNS
1. Receptors send messages to CNS with affarent sensory neurons
2. hits the dorsal root ganglion
3. Processed in the CNS (interneurons)
4. Goes back out to Skeletal muscles through the somatic motor neurons
5. Goes back out to smooth muscle, cardiac muscle, and glands through the autonomic motor neurons
76
What is the structure of a neuron
Dendrites
cell body (soma)
axon
Synapse
77
What is the structure of a synapse
1. Endfoot or terminal bouton
2. Synaptic vessicles
3. Neurotransmitters
4. Synaptic cleft
5. presynaptic membrane
6. postsynaptic membrane
78
How do neurons communicate across synapses
using neurotransmitters
79
how do neuro transmitters work
they are released from the presynaptic membrane, across the synapse, and bind to receptors on the post synaptic membrane
80
What are the different kinds of postsynaptic potentials
Excitatory and Inhibitory
81
What are EPSP's
graded potentials that cause depolarization, leading towards threshold
82
What are IPSP's
graded potentials that cause hypopolarization, leading away from threshold
83
What are the two types of summation
spatial and temporal
84
what is spacial summation
summing up of potentials from different presynaptic neurons in a close proximity to one another
85
What is temporal summation
summing up of potentials from a single presynaptic neuron that are fired rapidly
86
What is a motor unit
A neuron and all of its associated muscle fibers
87
What leads to appropriate contraction
a balance of IPSP's and EPSP's
88
How are the muscle fibers for specific motor units organized
they are kind of spread out all over the place
89
How does the glycogen depletion method show you which muscle fibers are part of a certain motor unit
I don't know
90
What are the things to consider when classifying motor units
1. Physical Size
2. Number of fibers
3. Force generation
4. rate of force production
5. fatiguability
91
What are the three motor unit types
1. FF - Fast fatiguable
2. FR - Fast Fatigue resistant
3. S - Slow
92
```
What is the...
- Twitch Tension
- Twitch time generation
- Fatigue index
- "sag" present
for FF motor units
```
1. High Twitch tension
2. Fast twitch time contraction
3. Low fatigue index
4. Yes, sag is present
93
```
What is the...
- Twitch Tension
- Twitch time generation
- Fatigue index
- "sag" present
for FR motor units
```
1. Moderate twitch tension
2. Fast twitch time contraction
3. High fatigue index
4. Yes, Sag is present
94
```
What is the...
- Twitch Tension
- Twitch time generation
- Fatigue index
- "sag" present
for S motor units
```
1. Low twitch tension
2. Slow twitch time contraction
3. High fatigue index
4. No, Sag isn't present
95
What is the correspondence between motor unit types and muscle fiber types
FF is mostly FG muscle fiber types (Type IIx)
Fr is mostly FOG muscle fiber types (Types IIa)
S is mostly SO muscle fiber types (type I)
96
Type 1
```
Slow twitch
Slow
Slow Oxidative
Intermediate
Tonic (postural)
```
97
Type IIa
```
Fast Twitch
FAst, FAtigue Resistant
Fast, oxidative, glycolytic
Red
Phasic
```
98
Type IIx
```
Fast twitch
Fast fatiguable
Fast glycolytic
white
phasic
```
99
What is the all or none principle in motor unit recruitment
That once a motor unit is recruited, all of it's muscle fibers contract
100
How is the recruitment of motor units organized
smallest ones first, large ones follow
101
What is selective recruitment
I don't know
102
What is the motor recruitment graph like
Y axis is force production
X axis is number of motor units recruited
Graph goes up like stairs, shorter ones first, taller ones toward the end.
this indicates that the smaller motor units are recruited first.
103
What do we know about the variations in size of motor neurons
1. Cell bodies and axons can vary greatly in size
2. large nerve fibers innervate more muscle fibers
3. Amplitude of the impulse is directly related to axon diameter
4. Inverse relationship between excitability and size???
104
Is the Stretch threshold related to the size of the action potential
yep
105
What influences the protein make up of the muscle
the nervous output
106
What are the three muscle functions
Strength
power
endurance
107
what is strength
How much force you can generate
- One rep max
- determined by muscle size
108
What is power
```
The application of strength
Force*distance/time
Applies to all activities
best measure of performance
determined by fiber type, size and metabolism
```
109
What is endurance
Sustained muscular contractions (not just aerobic exercise)
Running, jogging, biking
determined by muscle fiber type and metabolism
110
What is contraction
Tension generated
111
What are the types of contraction
isometric
| isotonic
112
What are isometric contractions
static (not moving)
| postural muscles
113
What are isotonic contractions
dynamic (moving)
| most muscles
114
What are the two types of isotonic contractions
1. Concentric (shortening)
| 2. Eccentric (Lengthening)
115
What are the factors that determine muscle force production
1. Muscle mass
2. Motor unit characteristics
- Number
- Type
3. Initial muscle length
4. Contraction velocity
116
What is the length tension relationship like
if the muscle is too shortened, or too stretched then it won't be able to produce as much tension as if it were about its resting length
117
What is the optimum length for peak muscle tension
100- 120% of resting length
118
Why does the length of the muscle matter
1. The amount of myosin/actin interaction
| 2. The viscoelastic property of muscle
119
How does the joint angle matter
the angle influences the length of the muscle, and it influences the angle of pull of the muscle, both of which influence force production
120
What is the force velocity graph like
Velocity on Y
Load on X
the higher the velocity the lower the load and vice-versa. shaped like a quarter pipe
121
When is maximum velocity of muscle shortening the greatest
at the lowest force
122
what makes certain loads have different speeds in the end
the percentage of that muscle that it fast twitch fibers. the more fast twitch fibers the faster the shortening will be
123
What type of motor unit has the most muscle fibers
Type 2 has more muscle fibers than type 1
124
What type of motor unit fires faster
type 2 fires faster than type 1
125
What does ADL stand for
Activities of daily living
126
Why should one strength train
to increase muscle function and make it easier to do ADL's
127
What is the principle of overload
in order to increase the strength of the muscle and thereby its mass, you need to work the muscle beyond what it normally does
128
What are different ways to overload your muscle
Frequency, intensity, and duration
129
What is the principle of specificity
it says that what you decide to work out is what you gain. You can isolate muscles that you want stronger, movements you want to improve, and the type of metabolism you prefer
130
what is progressive resistance training
- basis for most weight training programs
| - You keep adding more resistance as you become stronger
131
does endurance training increase strength
nope
132
What are the principles of strength training
1. Must execise near thier peak tension
2. Sets, reps, and breaks refined
3. 3-4 days per week
4. Specificity - workout the action you want to improve, at the same speed,
133
What does ENDURANCE training do for muscle strength
not a lot
134
what does progressive resistance training do for muscle strength
increases muscle strength
135
What does a combination of endurance training and resistance training do for muscle strength
shows about the same increase, maybe a little more than just resistance training alone
136
What can maximal training do for you
increase the motor unit recruitment, which means you have more muscle mass that gets activated, which means your submaximal contractions will be more efficient
137
What is hypertrophy
an increase in muscle size
138
what is transient hypertrophy
temporary, not functional increase in muscle size, (movement of fluids)
139
What is chronic hypertrophy
addition of protein to the muscle, is lasting, and functional
140
What is hyperplasia
increase in number of muscle fibers
141
How common is hyperplasia in humans
doesn't happen
142
How does whole muscle hypertrophy happen
1. Increase in # of myofibrils
| 2. Increase in muscle cell size
143
How does hypertrophy increase strength
more myofibrils you have = more myosin and actin = more pulling = more strength
144
Which muscle fiber type is most responsive to resistance training
Type II, but type I still hypertrophies
145
What does the graph look like for time course - neural factors and hypertrophy look like
Y axis is percent contributions to gains in maximal strength
X axis is time.
The neural contribution starts out much higher than that of the hypertrophy contribution, but they slowly merge until at about 11-12 weeks they cross and hypertrophy begins to contribute more than neural factors
146
What is responsible for initial strength gains
neural factors
147
what happens neurologically that causes these strength gains
1. More motor neurons get recruited
| 2. They get more coordinated too
148
What happens to % fiber type over 8 weeks of resistance training
- Type 1 doesn't change much
- Type IIa increases a lot
- Type IIx decreases proportionally to type IIa
149
How long does it take for hypertrophy to start being notacable
8 - 10 weeks
150
What does the hypertrophy time table depend on
training stimulus and the individual
151
Why does hypertrophy take a while
protein accretion takes time
152
What is crosstalk
when you work one side and leave the other, that side will begin to get strength gains too
153
Are there wholesale changes from type 1 to type 2 muscle fibers with training
no
154
What happens to % muscle fiber with endurance training
possible to get increased type 1 %
155
What happens along the muscle fiber type continuum with training
Hybrid fibers decrease and everything shifts toward type 1 and type 2a fibers
156
why is type IIx left in untrained muscle
because the muscle tries to make up for it's deficiencies by having more type IIx
Optimizes for it's conditions
157
Who gets more absolute gains with resistance training
Men
158
Who gets more relative gains with resistance training
same between men and women
159
Men have more muscle mass
men have more hypertrophy
160
Does combined training lead to lower gains in strength than strength training alone
nope, not really at least
161
does order of exercise matter in same day exercising
yep
162
What are the gains of concurrent training
both Endurance and strength
163
What is DOMS
Delayed onset muscle soreness
164
How long after working out does doms set in
24-48 hours
165
What are the unique aspects of pain experienced with DOMS
- pain on palpation
| - pain with contraction
166
What exercises cause DOMS more than others
Eccentric, or novel exercises
167
Why does eccentric exercise cause Doms
Excessive stress or strain (length and load)
168
What is the primary damage from DOMS
mechanical;
- sarcolemma is disrupted
- Z line streaming (broken up Z lines)
- Creatine kinase elevated in blood
169
What is the secondary damage from DOMS
Inflammation
170
What causes the pain from DOMS
Inflammation and swelling
171
Are symptoms of DOMS relative to level of damage
yep
172
How long does pain last with doms
4-7 days
173
Does DOMS result in decreased function
yeah,
- immediate strength loss
- 1-2 week recovery
174
What is the repeated bout effect
There will be significantly less damage and pain after your 2nd bout of the exercise
175
What is a possible explanation for the repeated bout effect
the cytoskeleton, it appears that there are serious increases in Desmin after the first workout
176
How come some people don't get as sore as others
genetics, there are some responders and some non responders
177
how can you avoid/reduce DOMS
1. reduce eccentric part of the lift
2. Slower program progression
3. Get in and get it overwith
178
How does warming up/stretching affects DOMS
there is no evidence that it works
