Week 2 Questions Flashcards
1
Q
- What is the diffusion potential?
A
a. The potential difference generated across a membrane when an ion diffuses down its concentration gradient
b. Can only be generated if the membrane is permeable to that ion
2
Q
- The ____ of the diffusion potential depends on the size of the concentration gradient.
A
a. Magnitude
3
Q
- What is the equilibrium potential?
A
a. The diffusion potential that exactly balances or opposes the tendency for diffusion down the concentration gradient
4
Q
- The electrochemical equilibrium occurs when the chemical and electrical driving forces acting on an ion are ___ and ___.
A
a. Equal and opposite
5
Q
- How would we calculate the equilibrium potential?
A
a. Using the Nernst equation
6
Q
- What is a membrane potential?
A
a. Arise when there is a difference in electrical change between both sides of a membrane
7
Q
- The charge difference of the membrane potential, can result from what two things?
A
a. Passive ion diffusion– 90%
b. Electrogenic pumping– 10%
i. Sodium-potassium pump
8
Q
- How does K+ maintain electroneutrality?
A
a. Leak channels
b. More permeable than Na+
9
Q
- As K+ goes out of the cell it is losing positive charges and therefore the ____ becomes more positive.
A
a. Outside
i. Assuming the cell membrane is only permeable to K+
10
Q
- As Na+ goes into the cell, the ____ becomes more positive.
A
a. Inside
i. Assuming the cell membrane is only permeable to Na+
11
Q
- The resting membrane potential is closer to the equilibrium potential of K+ than it is to Na+. Why is this?
A
a. The membrane is more far more permeable to K+ than Na+
12
Q
- What two processes allow for more K+ than Na+?
A
a. Sodium-potassium pump
b. K+ leak channels
13
Q
- The Nernst Equation allows us to determine the equilibrium potential for each ion when..
A
a. We assume that the membrane is only permeable to that ion
b. We know the chemical concentrations across the membrane
14
Q
- What does the Goldman Equation?
A
a. Can estimate the membrane potential for multiple ions
b. We have to know the permeability and concentration of the ions across the cell
15
Q
- What three characteristics does diffusion potential depend on?
A
a. Polarity of each charge
b. Permeability of membrane to each ion
c. Concentration gradients
16
Q
- The resting membrane potential is closest to the equilibrium potential for the ion with the highest ______.
A
a. Permeability
17
Q
- What is the resting membrane potential?
A
a. -90mV
18
Q
- What maintains the resting membrane potentials?
A
a. Passive Ion diffusion
b. Electrogenic pumping
i. Sodium-potassium pump
19
Q
- What is an action potential?
A
a. Basic mechanism for transmission of information in the nervous system
20
Q
- An action potential is the regeneration of depolarization of membrane potential that___ along an ___ membrane.
A
a. Propagates: conducted without decrement
b. Excitable: capable of generating action potentials
21
Q
- What is the resting membrane potential?
A
a. -90 mV
22
Q
- Depolarization is the process of making the membrane potential___ negative .
A
a. less
i. Moving closer to 0 mV
23
Q
- Hyperpolarization is the process of making the membrane potential ___negative.
A
a. More negative
i. Moving farther away from 0 mv
24
Q
- ____is when the membrane potential is moving back towards resting membrane potential.
A
a. Repolarization
25
7. What is excitability?
a. The ability of the membrane to shift its polarization in response to stimuli from resting membrane potential to depolarized state and back
26
8. What is threshold potential?
a. The membrane potential at which occurrence of the action potential is inevitable
b. -50mV
27
9. The ___ is the flow of positive charge into the cell and causes the membrane potential to become ____.
a. Inward
| b. Depolarize
28
10. The ____ is the flow of positive charge out of the cell and causes the membrane potential to become ___.
a. Outward
| b. Hyperpolarize
29
11. What is the overshoot?
a. Also called polarize
b. The portion of the action potential where the membrane potential is positive
c. Pass 0 mV
30
12. What does it mean to undershoot?
a. Also called hyperpolarization afterpotential
b. The portion of the action potential (following repolarization) where the membrane potential is actually more negative than at rest
31
13. What is the refractory period?
a. A period during which another normal action potential CANNOT be elicited in an excitable cell
b. Can be absolute or relative
32
14. Action potentials are an _____ event.
a. All-or-none
33
15. Action potentials have constant___.
a. Amplitude
34
16. True/false: action potentials can summate.
a. FALSE
35
17. Action potentials are initiated by____.
a. Depolarization
36
18. Action potentials involve changes in_____.
a. Permeability
37
19. Action potentials rely on ____channels.
a. Voltage-gated
38
20. If we have a stronger stimulus, will we have a stronger amplitude?
a. No
| i. Constant amplitude
39
21. Fibers with ___ diameter conduct faster than ___fibers.
a. Larger
i. More myelination
b. Small
40
22. Why do voltage-gated sodium channels open when the membrane potential becomes less negative and reaches threshold?
a. The stimulus causes the membrane to become more positive (depolarization)
b. The voltage sensor repels the positive charges, causing the portion of the channel to slide up
c. This opens the inactivation gate and allows sodium to flow into the cell
41
23. What does the resting membrane look like?
a. Approximately -90mV
b. High conductance/permeability of K+
c. Low conductance of Na+
42
24. At resting membrane potential, the ____ gate is closed
a. Activation gate
43
25. What causes the activation gate to open?
a. Depolarization of the membrane (-90 mV to +35 mV)
| b. Reaches threshold
44
26. What occurs during the upstroke of the action potential?
a. Influx of Na+ into the cell
| b. Happens very quickly
45
27. The same stimulus that opens the activation gate also closes the ___ gate and OPENS the ___ channels.
a. Inactivation
b. K+
i. These two are both delayed responses
46
28. At some point the activation gate is ___ and the inactivation gate is open.
a. Closed
47
29. The downstroke of the action potential is caused by what two factors?
a. Closure of the Na+ channels
| b. Efflux of K+ out of the cell
48
30. The efflux of K+ causes the cell to become____.
a. Hyperpolarized
| i. More negative
49
31. Why does the after hyperpolarization phase occur?
a. Because the delayed closure of the K+ channels
| b. K+ I higher than at rest and the membrane potential is driven even close to the K+ equilibrium potential
50
32. Is the after hyperpolarization phase always seen?
a. No
51
33. What medications block voltage-gated Na+ channels?
a. Tetrodoxtoxin
| b. Lidocaine
52
34. What medications block voltage-gated K+ channels?
a. TEA-- tetraethylammonium
53
35. What are the three combinations of the gates' positions?
a. Closed but available
i. Occurs at resting membrane potential
ii. Activation gate is closed
iii. Inactivation gate is opened
b. Open
i. Occurs during the upstroke of the action potential
ii. Both gates are briefly open
c. Inactivated
i. Occurs at the peak of the action potential
ii. Both gates are closed
54
36. How do the Na+ channels return to the closed but available state?
a. During repolarization, the inactivation gate opens
55
37. True/false: action potential propagations have specific direction.
a. False-- they do not have a specific direction
| i. Due to activation gates being shut-- Refractory period
56
38. What are refractory periods?
a. Excitable cells cannot produce normal action potentials
| b. Difficult or impossible for another action potential to occur
57
39. What are the two types of refractory periods?
a. Absolute
| b. Relative
58
40. What is the absolute refractory period?
a. Overlaps with almost the entire duration of the action potential
59
41. What is the basis for the absolute refractory period?
a. The closure of the Na+ channels in response to depolarization
60
42. What is relative refractory period?
a. Begins at the end of the absolute refractory period
| b. Overlaps primarily with the period of the hyperpolarization afterpotential
61
43. During which refractory period can an action potential be elicited?
a. Relative
| i. Only if greater than usual depolarization current is applied
62
44. What is accommodation?
a. When a nerve or muscle cell is depolarized slowly or is held at a depolarized level
b. May pass threshold without an action potential being fired
63
45. If depolarization occurs slowly enough, the Na+ channels ___.
a. Remain closed
64
46. What is hyperkalemia?
a. Example of accommodation
b. Elevated [K]
c. The cell is less likely to fire an action potential because the sustained depolarization closes the inactivation gates on the Na+ channels
65
47. What surrounds the axons?
a. Myelin sheath
66
48. ____ in the CNS surround the axon and are responsible for myelination.
a. Schwann cells
| i. Produces myelination
67
49. Breaks in the myelin sheath are called _____.
a. Nodes of ranvier
68
50. Voltage-gated Na+ channels are localized near the ____.
a. Nodes of Ranvier
69
51. What is saltatory conduction?
a. Where the current is amplified at the nodes of ranvier by voltage gated Na+ channels
i. Makes propagation much faster
70
52. Is the conduction speed of action potentials faster on a myelinated or non-myelinated axons?
a. Myelinated
i. On non-myelinated axons the sodium channels are activated at each spot vs. on a myelinated axon the sodium channels are activated at the nodes of Ranvier
71
53. _____ is an immune-mediated inflammatory demyelinating disease of the CNS.
a. Multiple sclerosis
72
54. How does MS affect the CNS?
a. The action potential won't be able to pass and the CNS won't be able to provide normal functions
73
55. Do the symptoms go away completely?
a. No
74
56. What is conduction velocity?
a. The speed at which action potentials are conducted along a nerve/muscle fiber
b. Time/length constant
75
57. What is the time constant?
a. Indicates how quickly a cell membrane depolarizes in response to an inward current or how quickly it hyperpolarizes in response to an outward current
76
58. What are two factors that affect the time constant?
a. Membrane resistance
| b. Membrane capacitance
77
59. When the membrane resistance is high, the time constant ____.
a. Increased
78
60. When the membrane capacitance (ability to store charge) is high, the time constant is ___.
a. Increased
79
61. What are two mechanisms that increase conduction velocity along a nerve?
a. Increase nerve diameter
i. The larger the fiber, the lower the internal resistance
b. Myelination
i. Increases membrane resistance and decreases membrane capacitance
80
1. What are synapses?
a. How cells communicate
81
2. What are the two different types of synapses?
a. Electrical
| b. Chemical
82
3. What is an electrical synapse?
a. Allows current to flow from one excitable cell to the other via low resistance pathways called gap junctions
83
4. Where are gap junctions found?
a. In cardiac muscles and some types of smooth muscle
84
5. Transmission of information in the electrical synapses is___.
a. Bidirectional
85
6. What are chemical synapses?
a. There is a gap between the presynaptic membrane and the postsynaptic membrane called the synaptic cleft
86
7. Information in the chemical synapses is transmitted via___.
a. Neurotransmitters
87
8. The change in potential on the _____ can either be ____ or ___.
a. Postsynaptic side
| b. Excitatory or inhibitory
88
9. In which of the synapses is there a presence of a synaptic delay?
a. Chemical
| i. No synaptic delay in the electrical synapse
89
10. In the chemical synapses, what causes this delay?
a. The multiple steps in chemical neurotransmission to occur
90
11. What is a motorneuron?
a. The nerves that innervate muscle fibers
91
12. What is a motor unit?
a. Comprises of a single motor neuron and the muscle fibers it innervates
92
13. What is the motor end plate?
a. Where the nerve innervates the muscle fiber
93
14. What is the importance of the invaginations?
a. Increase surface area available for receptors
| b. Accept more neurotransmitter
94
15. What occurs at the NMJ?
a. An action potential travels down the end of the axon terminal
b. The action potential stimulates the opening of calcium channels
c. Calcium enters the cell
d. Once calcium enters the cell it stimulates the release of the vesicles to bind to the membrane
e. Once the vesicles bind to the membrane they release their neurotransmitters, in this case ACH
f. Ach enters the synaptic cleft and travels to the post synaptic membrane
g. Attach to the nicotinic receptors on the postsynaptic membrane
i. Only found in the muscle cells
h. Causes a conformational change that allows Na+ into the cell
i. Changes can be excitatory or inhibitory
i. Opens up voltage-gated Na+ channels
j. Action potential
95
16. ACH-channels are large enough to allow passage of Na+, K+, and Ca++, so why do more Na+ ions pass through?
a. The -ve potential inside the membrane attracts Na+ influx and prevents K+ efflux
96
17. What is the end-plate potential?
a. The local positive potential
b. Responsible for generation of the AP
c. Can increase resting potential by 50-75 mV
97
18. As long as ___ is present is continues to stimulate the motor-end plate.
a. ACH
98
19. What would happen if ACH was not removed from its receptor?
a. Contraction wouldn't happen
99
20. What are the two ways ACH is removed?
a. ACH-esterase enzyme
i. 50%
b. Spillover of ACH
i. Spill into the synaptic cleft and away from the NMJ
100
21. What forms ACH?
a. Choline and acetyl CoA
101
22. What is the function of the T-tubules in excitation-contraction coupling?
a. Responsible for carrying depolarization from action potentials at the muscle cell surface to the interior of the fiber (deep myofibrils)
102
23. Where is the dihydropyridine receptor (DHPR) located?
a. The membrane of the t-tubule
103
24. Where is the ryanodine receptor located?
a. On the membrane of the SR
104
25. What is the function the DHPR?
a. Opens voltage-gated Ca+ channels once the signal comes down the t-tubule
105
26. Once the channels open the calcium flows from the inside of the cell to the outside of the cell, and then binds to the ____ receptors.
a. Ryanodine receptor (RyR)
106
27. The binding to the RyR causes a conformation change that then allows…
a. Ca+ stored in the SR to be released into the cytoplasm
107
28. What happens when there is a high amount of Ca++ in the cytoplasm?
a. Calcium attached to the troponin C
i. Myosin-actin binding
ii. Movement
108
29. How does Ca++ get transported from the cytoplasm back into the SR?
a. SERCA 2
109
30. What are the steps involved in pumping calcium back into the SR?
a. Action potentials come down the t-tubule
b. Activates voltage-gated Ca++ channels
c. Ca++ is released into the cytosol and binds to the RyR
d. Once the RyR is stimulated it releases Ca++ from the SR into the cytosol
e. Initiates muscle contraction
f. Ca++ is the pumped against its concentration gradient using ATP and SERCA2 back into the SR
110
31. What is this process called?
a. Calcium-induced calcium release (CICR)
111
32. What does SERCA stand for?
a. Sarcoplasmic Endoplasmic Reticulum Ca++ ATPase
112
33. Ca++ is accumulated in the SR by the pump action of ____.
a. SERCA
113
34. Ca++ in the SR binds to _____.
a. Calsequestrin
114
35. What happens once Ca++ is reaccumulated back into the SR?
a. Relaxation
115
36. What are the 5 sets of ion channels involved in neuromuscular transmission?
a. Voltage-gated Ca++ channels
b. ACH-receptors (nicotinic receptors)
c. Voltage-gated Na+ channels
d. DHPR
e. RyR
116
37. Steps of neuromuscular transmission
a. Nerve impulse depolarizes the axon terminal, and opens voltage-gated Ca++ channels. Ca++ rushes into the nerve axon stimulating the release of ___.
i. ACH
b. Ach binds to ____, causing a conformation change that opens the channel causing Na+ influx
i. Nicotinic receptors
c. The local depolarization causes opening of voltage-gated __ channels, allowing __ influx and self-propagation of AP.
i. Na+
d. Impulse reaches the _____, causes the voltage-sensitive ____ to open.
i. t-tubule
ii. DHPR
e. This stimulates the ___ release channel and activates the ___.
i. Ca++
ii. RyR
f. The RyR releases Ca++ from the ___ into the ___.
i. SR
ii. The muscle cytoplasm
117
38. Which agent blocks ACH release from the nerve terminal and could potential cause paralysis and eventually death from respiratory failure?
a. Botulinum
118
39. Which agent competes with ACH for its receptor?
a. Curare
i. Max doses cause paralysis and death
ii. Prevents ACH from binding
119
40. Which agent inhibits Na+ channels and is found in the Japanese puffer fish?
a. Tetrodotoxin
120
41. Which agent would cause long-lasting contractions?
a. Neostigmine
| i. AChE inhibitor
121
42. Which agent would prevent action potentials from happening?
a. Tetrodotoxin
122
43. Which agent blocks choline reuptake, thus depleted ACH?
a. Hemicholinium
| i. Premature fatigue
123
44. True/false: if these agents are given at any dosage, there is a chance for paralysis and eventually death.
a. False: they have to be given in proper dosages
124
45. Excitatory neurotransmitter___ the postsynaptic cell.
a. Depolarize
| i. EPSP
125
46. What are some examples of EPSP?
a. ACH, norepinephrine, epinephrine, dopamine, glutamate, serotonin
126
47. Inhibitory neurotransmitters _____ by opening Cl- or K+ channels.
a. Hyperpolarize
127
48. What are some examples of IPSP?
a. GABA and glycine
128
1. Anatomy of a muscle from smallest to largest structure
a. filaments
b. Muscle fiber (cell)
c. Fascicle
d. Muscle
129
2. The ___ surrounds the muscle fibers.
a. Endomysium
130
3. The ____surrounds muscle fascicles.
a. Perimysium
131
4. The entire muscle is surrounded by the ___.
a. Epimysium
132
5. Blood vessels and nerves that supply the muscle fibers are found within the ____.
a. Perimysium
133
6. What is the sarcomere?
a. Portion of the myofibril that lies between 2 adjacent Z disks
134
7. The light bands, or the I bands, only contain ____.
a. Actin
135
8. The dark bands, or the A bands, contain ____.
a. Actin and myosin
136
9. The z disks run down the middle of the ___ band.
a. I
137
10. Where is the bare zone?
a. Also called the H zone
b. Located in the center of the sarcomere
c. Contains only thick filaments
138
11. Where is the M line?
a. In the middle of the bare zone
| b. Links central portions of the thick filament together
139
12. What is the function of actin?
a. Not just present in muscles
| b. Determines the shape of cell's surface and are necessary for whole cell locomotion
140
13. How does actin play a role in whole cell locomotion?
a. Moves the cell by "treadmilling"
i. Actin has a plus end and a minus end
ii. The rate of polymerization if faster on the + end
iii. It can disassemble and reassemble very quickly
1. Reassembly occurs on the + end which moves actin
141
14. True/false: actin works alone.
a. False: actin has multiple assistants
142
15. Alpha-actin acts as an accessory protein that anchors actin with ____ which allows space for myosin to bind.
a. Lots of space
143
16. _____binds actin very tightly and prevents myosin from binding.
a. Fimbrin
144
17. _____nucleates assembly and remains associated with the growing plus end/
a. Formin
145
18. ____binds subunits, prevents assembly.
a. Thymosin
146
19. The _____ prevents assembly and disassembly at the plus end
a. Capping protein
147
20. ____stabilizes the actin filament.
a. Tropomyosin
148
21. ____ binds actin to the membrane.
a. Spectrin
149
22. The myosin superfamily is a membrane of a larger family of ___.
a. Motor proteins
150
23. Where did myosin II get its name from?
a. Two heads
151
24. Myosin is composed of __heavy chains and ___ light chains.
a. 2 heavy
| b. 4 light
152
25. The protruding heads are called ____.
a. Cross-bridges
153
26. True/False: each myosin head is independent of each myosin head.
a. True-- this is what makes muscle contractions smooth
154
27. Muscle contraction occurs by sliding of the myosin filament past the actin filament ____ any change in the length of either filament.
a. WITHOUT
155
28. This is called the _____.
a. Sliding filament theory
156
29. Cap Z binds to actin at the __ end.
a. Plus
157
30. Alpha-actin binds actin to the ___.
a. z-disk
158
31. Cap Z and alpha-actin together prevent ____.
a. Depolymerization
159
32. ____ acts as molecular rule and helps determine the exact length of each actin filament.
a. Nebulin
160
33. What caps the minus end and stabilized it?
a. Tropomolulin
161
34. What is the function of titin?
a. Acts as the molecular spring and allows the muscle fiber to recover after being overstretched
162
35. What are the steps of the walk-along theory?
a. Myosin and actin are attached-- rigor conformation
b. ATP binds to the myosin head and decreases its affinity of actin and releases the actin filament
c. ATP becomes hydrolyzed (producing ADP and Pi), the myosin head is cocked into position
d. P is released from the myosin head and strengthens the bond between myosin and actin
e. Myosin binds again to the actin and ADP is released and allows myosin head to return to its original position
f. Myosin returning to its original position triggers the power stroke
163
1. At____ all the myosin cross-bridges are in contact with action.
a. Optimal length
164
2. What happens if the sarcomeres are too far apart?
a. Actin is pulled all the way out
b. No cross-bridge over lap
c. Zero tension
165
3. What happens is the sarcomeres are too close?
a. The Z disks bump into each other
| b. Strength of contraction drops rapidly
166
4. What is passive tension?
a. The tension developed by simply stretching a muscle to different lengths
167
5. What produces passive tension?
a. Cytoskeleton (titin) and other connective tissue
168
6. When does the passive component come into play?
a. Only at longer lengths
169
7. What is total tension?
a. The tension developed when a muscle is stimulated to contract at different preloads
b. It is the sum of active tension developed by the cross-bridge cycling in the sarcomeres and the passive tension caused by stretching the muscle
170
8. What is active tension?
a. Represents the active force developed during cross-bridge cycling
171
9. How is active tension determined?
a. By subtracting the passive tension from the total tension
172
10. As the muscle is continuously stretched ___ tension decreases.
a. Active
173
11. As we stretch the muscle, ___ tension increases.
a. Passive
174
12. In the force-velocity relationship, if the load is increased, the velocity is___.
a. Decreased
| i. Cross-bridges cannot cycle as rapidly against higher resistance
175
13. Why is the maximal velocity the same at all three initial muscle lengths?
a. When the load is at zero, the velocity of shortening will be at its max
176
14. Why is it that the maximum amount of force at a shorter length is only 2 kg (not much)?
a. The shorter the length (too short), less contraction, less force
177
15. The speed of contraction is determined by the ___ of myosin ATPase.
a. Vmax
178
16. _____ are fast and white.
a. High Vmax (think speed of light)
179
17. ____ are slow and red.
a. Low Vmax
180
18. Which type of fiber has a rapid rate of shortening?
a. High Vmax
181
19. Which type of fiber has a rapid cross bridge cycling?
a. High Vmax(fast)
182
20. Which type of fiber has slow cross bridge cyclinig?
a. Low Vmax (slow)
183
21. True/False: most muscles contain both fiber types but proportions differ.
a. True
184
22. True/False: all fibers in a particular motor unit will be of the same type.
a. True
185
23. Slow fibers are also known as ___.
a. Type I
186
24. Fast fibers are also known as ___.
a. Type II
187
25. Which type of fiber is glycolytic?
a. Fast twitch/ type II
188
26. Which type of fiber is oxidative?
a. Slow twitch/ type I
189
27. Which type of fiber has a high myoglobin content?
a. Slow twitch fibers
190
28. Which type of fiber has a low capillary density?
a. Fast twitch fibers
191
29. Which type of fiber does not have a lot of mitochondria?
a. Fast twitch
192
30. Which type of fiber has a low content of glycolytic enzymes?
a. Slow twitch
193
31. All fibers are ____ type in a given motor unit.
a. The same
194
32. Small motor units are used for?
a. Precise control
| b. Rapid reacting
195
33. What are large motor units used for?
a. Coarse control
| b. Slower reacting
196
34. Motor units overlap, which provides ____.
a. Coordination
197
35. What is force summation?
a. Increase in contraction intensity as a result of the additive effect on individual contractions
i. If we stimulate a muscle, we get a single twitchh
ii. If we keep stimulating the muscle at a faster rate-- tetanization
iii. ONLY changing the rate of the stimulus which increases the force of contraction
198
36. What are two ways to increase the force of contraction with increase the amplitude of the stimulus?
a. Multiple fiber summation
| b. Frequency summation
199
37. What is multiple fiber summation?
a. Results from an increase in the number of motor units contracting simultaneously (fiber recruitment)
i. Contributes to an increase in force contraction
200
38. What is the size principle?
a. The smaller motor units respond first and then the large motor units
i. The small motor units are more excitable and therefore respond first
201
39. What is the frequency summation?
a. Results from an increase in the frequency of contraction of a single motor unit
202
40. What is the staircase effect?
a. Increasing overall Ca++ availability in the myoplasm
i. If the muscle is stimulated before complete relaxation has occurred the new twitch will sum with the previous one
ii. If the action potential frequency is sufficiently high, the individual contractions are not resolved and a 'fused tetanus' contraction is recorded/
203
41. What is hypertrophy?
a. Caused by near maximal force development
b. Increase in actin and myosin
c. Myofibrils split
i. This is why we take protein after we workout
204
42. What is hyperplasia?
a. Very rare
b. Formation of new muscle fibers
c. Can be caused by endurance training
205
43. In both hypertrophy and hyperplasia, there in an increase in ____ but there I no change in ____ or _____ of contraction.
a. Force generation
b. Shortening capacity
c. Maximum velocity of contraction
206
44. During hypertrophy and hyperplasia the sarcomeres are added in ____.
a. parallel
207
45. In lengthening, there is no change in ____.
a. Force development
208
46. In lengthening, there is an increase in ___ and ____.
a. Shortening capacity
| b. Maximum contraction velocity
209
47. What are the causes of atrophy?
a. Denervation/neuropathy
b. Tenotomy
i. Muscle is no longer attached to the bone
c. Sedentary life style
d. Plaster cast
e. Space flight (zero gravity)
210
48. What are the consequences to muscle performance?
a. Degeneration of contractile proteins
b. Decreased max force of contraction
c. Decreased velocity of contraction
