Midterm Flashcards
(166 cards)
1
Q
What does an Enzyme increase?
A
The rate of chemical reactions
2
Q
What does an enzyme and mitochondria increase with?
A
Aerobic training
3
Q
Mitochondria
A
Contains enzyme involved in aerobic metabolism
4
Q
Actin
A
Thin myofilament
5
Q
Myosin
A
Thick myofilament
6
Q
Z-Disk
A
Thick structures perpendicular to actin
7
Q
Sarcomere
A
Arrangement of actins and myosins bordered by z-disks
8
Q
I-Band
A
Area that contains only actin
9
Q
A-Band
A
Dark area that contains myosin
10
Q
Tropomyosin
A
Protein that blocks the binding site for myosin and actin
11
Q
Troponin
A
Calcium binds to this causing troponin to lift the tropomyosin off the actin allowing myosin to bind to actin
12
Q
Actin and Myosin are what kind of proteins?
A
Contractile - Interact to form cross bridges to cause a contraction
13
Q
Troponin and Tropomyosin are what kind of proteins?
A
Regulatory - Regulate whether or not myosin and actin will form cross bridges
14
Q
Why is a larger muscle able to produce more force than a smaller muscle?
A
Large would have more actin and myosin which means there would be a greater number of cross bridges produced. There would also be more enzymes to produce more force output from the muscle
15
Q
Myofilament
A
Another name for actin and myosin
16
Q
Glycogen
A
The main storage form of carbohydrate in a muscle
17
Q
ATP
A
The main energy currency of a cell
18
Q
A motor neuron and all the muscle fibers it innervates
A
Motor Unit
19
Q
What shortens during a contraction?
A
I-Band -because actin slides over myosin
Sarcomere -because the z-disks get closer
20
Q
Composition of Myosin
A
- 2 heads that interact with actin (one forms cross bridges and one anchors)
- The type of heavy chain determines ATPase activity
21
Q
3 types of Myosin Heavy Chains
A
1) Type I- Slow Twitch
2) Type IIa- Intermediate Twitch
3) Type IIx- Fast Twitch
22
Q
Where is calcium stored in a muscle fiber?
A
Sarcoplasmic Reticulum
23
Q
The proteins that are found in a sarcomere:
A
- Actin
- Myosin
- ATPase
- Tropomyosin
- Troponin
24
Q
The proteins involved in a muscle contraction:
A
- Actin
- Myosin
- ATPase
- Tropomyosin
- Troponin
25
Proteins that can prevent muscle contraction:
- Tropomyosin
| - Troponin
26
ATPase
Enzyme involved in muscle contraction
27
How can fiber types be determined?
By genetics
28
Can fiber types change?
Yes, depending on your physical activity status
29
Change of fiber types during: Endurance Training
Type IIx- Type IIa- Type I
30
Change of fiber types during: Strength Training
Type I- Type IIa- Type IIx
31
Change of fiber types during: Lack of Training (detraining)
Type I- Type IIa- Type IIx
32
How will muscle fiber change from birth to the time a toddler learns to walk?
Type IIx- Type I
33
How can a muscle return to a relaxed state?
If tropomyosin is put over actin and by myosin releasing from actin. You will also need another ATP molecule to come in and bind to release it and remove calcium
34
Where is ATPase found?
In the Sarcoplasmic reticulum membrane in the muscle fiber
35
What fiber type has the highest amount of ATPase in the Sarcoplasmic Reticulum?
Type IIx
36
Steps for Muscle Contraction to occur:
1. Impulse is sent from a motor neuron in the spinal cord to the muscle fiber membrane
2. Electrical impulse travels down the muscle fiber membrane and down the transverse tubules
3. Calcium is released from the sarcoplasmic reticulum
4. Calcium binds to troponin
5. Troponin lifts tropomyosin off actin
6. Actin and myosin form cross-bridges
37
What protein has the greatest influence on the speed of muscle contraction?
Myosin heavy chains
38
What happens when myosin and actin interact?
They form cross bridges
39
Where do you get expenditure of energy? and what happens when you stop exercising?
In the membrane of the sarcoplasmic reticulum and after you stop exercising energy is still being expended because it is still pumping energy across the sarcoplasmic reticulum
40
2 types of muscle contraction
1) Isotonic
| 2) Isokinetic
41
Isotonic
Constant force
42
Isokinetic
Constant velocity
43
Concentric Contraction
Muscle is shortening, least amount of force
| ex) lifting weight, running up a hill
44
Isometric Contraction
Muscle stays the same length, 2nd most force
| ex) holding weight in one place, standing at top of hill
45
Eccentric Contraction
Muscle is lengthening, greatest force
| ex) lowering weight, running down the hill
46
D.O.M.S
Delayed Onset Muscle Soreness
47
What is delayed onset muscle soreness
- Soreness peaks at 24-48 hours after exercise which causes inflammation
- Soreness decreases after the peaks of repeated sessions
48
What causes muscle relaxation?
The pumping of calcium into the sarcoplasmic reticulum and binding of ATP to the actin-myosin cross bridge
49
What causes muscle contraction?
Binding of calcium to troponin and lifting of tropomyosin off actin
50
An important determinant of contraction velocity:
Myosin ATPase
51
What is important in achieving a high frequency of contractions?
Sarcoplasmic reticulum ATPase
52
Can you achieve a greater force output with isometric or dynamic concentric contractions?
Isometric because there are more stronger bonds between actin and myosin and a faster velocity
53
An advantage to training with eccentric contractions
Hypertrophy
54
A disadvantage to training with eccentric contractions
D.O.M.S
55
What happens to the Creatine Kinase levels in the blood after an intense workout?
They are elevated
56
How often should eccentric training be done?
Every 3 days because of D.O.M.S
57
T-Tubule
Structure that is part of muscle fiber membrane
58
Sarcolemma
Another name for the muscle fiber membrane
59
Characteristics of Exertional Rhabdomyolysis
Muscle damage, kidney damage, elevated creatine kinase levels in the blood (muscle damage)
60
Change of fiber types during: Spinal Cord Injury (Paralysis of the muscle)
Type I - Type IIa - Type IIx
61
Which motor neuron is the largest? Fast Twitch or Slow Twitch?
Fast Twitch
62
The force your muscles can exert at different muscle lengths depends on what?
The amount of actin-myosin overlap
63
Motor Unit
- A neuron and all the muscle fibers its connected to
- Contains only one type of muscle fiber
- Receives input from higher brain centers
64
Why would a boflex be good for training bench press or squat but not for training bicep curls?
Because the strength curve for bench press and squat require more resistance at the end of the ROM. The strength curve for bigger curve requires less resistance at the end of the ROM. The boflex provides more resistance at the end of the ROM and is weakest at the start.
65
What does attaching a chain to each end of a barbell while doing squats do?
As you lift up on the squat, you are lifting the chains adding additional weight/resistance. Therefore the ROM will be weakest when the chains are on the ground.
66
Is it more difficult to pedal a bike if your seat is to low or to high?
To low because it is the beginning of your ROM where you are the weakest and you don't have optimal actin and myosin cross bridges overlap. If you are higher up, you are more intermediate in you ROM so you are stronger here.
67
Force Summation
Happens when a muscle is repetitively stimulated
68
Tetanus
Happens in the nervous system, the force will plateau at maximal level
69
What is force summation caused by?
A constant release of calcium then absorbed to cause the repetitive stimulus. Before the muscle is fully relaxed, more calcium is released to cause a stronger contraction due to the calcium left from previous stimulus.
70
What is tetanus caused by?
All of the troponin being taken out and bound with calcium
71
Will summation occur more easily in a slow or fast twitch fiber?
Slow because it takes longer to relax. Fast twitch takes up calcium faster and has a longer relaxation period
72
Fast Twitch (Type IIa)
- Have a shorter time to peak tension compared to slow twitch fibers
- Have a slower reaction time than fast (IIx) fibers
- Have less endurance than slow twitch fibers
73
Axon
Extends from the nerve cell and branches to muscle fibers
74
How many types of fibers can a single motor unit have?
One
75
What type of response does a muscle fiber have when contracted?
All-or-None
76
Would gross motor units (walking) have a greater number of muscle fibers or would fine movement (finger actions)?
Walking
77
Electromyography (EMG)
Records electrical activity
78
Surface Electrodes
Activity from groups of motor units
79
Needle Electrodes
Through skin- read activity from individual motor units
80
Median Frequency
Determines the frequency of firing
81
Mean Absolute Value (MAV)
Determines the amplitude of the signal
82
Is EMG highest during stable or unstable exercise?
Unstable because motor unit recruitment is greater for stabilizing muscles
83
Which is better for activating/recruiting muscles: Free Weights or the Smith Machine?
Free Weights
84
What type of muscle fiber would a muscle with a low frequency of EMG burst have?
Type I
85
Would you be able to train with a greater velocity of movement when doing bicep curls on a swiss ball or standing on the ground?
Standing on the ground (velocity x force=max power)
86
Would you be able to lift a heavier weight while doing bicep curls on a swiss ball or standing firmly on the ground?
Standing on the ground
87
Which would involve a greater motor unit activation of stabilizer muscles: Doing bicep curls standing on the ground or while on a swiss ball?
Bicep curl while on a swiss ball
88
What detects ATPase?
Myosin heavy chains
89
Advantage of breaking down carbohydrates
Energy forms carbohydrates quickly
90
Disadvantage of breaking down carbohydrates
Lasts a short amount of time
91
Oxidative Enzymes
Slow twitch- have a lot of good endurance
92
Slow Twitch Fibers
- Greater capillarization
- More mitochondria
- Dark in color (red)-has myoglobin
93
Fast Twitch Fibers
- Larger
- Easier to hypertrophy
- Have more glycogen
94
Action Potential
Located along the axon of a motor neuron
95
Myelin Sheath
Covers the axon (insulator of charge)
96
Nodes of Ranvier
Gaps in the myelin that allows maintenance of action potential strength
97
What causes faster conduction velocity of axon?
The more myelin or thicker the axon
98
What type of muscle fiber has the thickest axons?
Fast Twitch
99
Summary of action potential from axon to muscle:
1) Action potential opens calcium channels
2) Calcium diffuses into axon
3) Vesicles release ACh into synaptic cleft
4) ACh binds on receptor membrane opening channel (allows Na in and K out)
100
Contraction Steps:
1) Action potential travels down the axon
2) ACh vesicles merge with the axon membrane
3) ACh is released into synaptic cleft
4) Sodium enters the muscle fiber
5) Potassium leaves the muscle fiber
6) Action potential travels down the t-tubule
7) Calcium is released from sarcoplasmic reticulum
8) Calcium binds with troponin
9) Tropomyosin is lifted off actin
10) Myosin binds with actin
101
What is the membrane of the cell permeable to?
Potassium
102
What is the charge of the inside of the cell relative to the outside?
Negatively charged
103
What is the opening of sodium channels due to?
ACh binding and the change in charge
104
Depolarization
Entry of Sodium (positive)
105
Repolarization
Exit of Potassium (negative)
106
Where does depolarization and repolarization occur?
In both the muscle cell membrane and the nerve cells and their axon
107
Acetylcholine
Chemical messenger between axons and muscle fibers
108
Transverse Tubule
Indentation of the muscle fiber membrane (sarcolemma)
109
Sodium and Potassium
These are exchanged across the sarcolemma during contraction
110
Motor Cortex
Part of the brain where voluntary contraction originates
111
Hyperpolarize Change
Membrane potential changes from -70mV to -90mV
112
Depolarize Change
Membrane potential changes from -90mV to 40mV
113
Repolarize Change
Membrane potential changes from 40mV to -70mV
114
Where do motor units receive their information from?
The brain center, specifically the motor cortex and sensory neurons
115
What determines whether an action potential is generated in a motor neuron or not?
The sum of the excitatory and inhibitory post-synaptic potentials
116
Input from one neuron to another can be:
1) Inhibitory
| 2) Excitatory
117
An action potential can be generated by:
1) One of few neurons delivering repetitive stimuli over a short period of time to the motor neuron
2) A bunch of excitatory post synaptic potentials can be delivered from different neurons to a motor neuron
118
How does motor unit recruitment change as someone goes from a slow walk to a jog to a sprint?
By recruiting slow twitch fibers from the walk to the jog. From the jog to the sprint, fast twitch fibers are recruited.
119
What type of fiber is usually recruited first, second and third?
Slow, intermediate then fast
120
If all of your motor units are active, you can increase your force of muscle contraction by:
1) Increasing the frequency of firing rates
- summation and tetnus
2) Increasing the number of motor units recruited
121
What is the purpose of having inhibitory input to a motor neuron?
To prevent injury by inhibiting antagonist muscle group
122
What are the 2 main muscle receptors?
1) Muscle spindle
| 2) Golgi Tendon Organ
123
Golgi Tendon Organ
- Activated by tension
- Inhibits muscle contraction
- Found at the junction between tendons and muscle fibers
124
How can you override the Golgi tendon inhibition of motor units?
Using your higher brain centers
125
Muscle Spindles
- Sensitive to stretch
- Responsive to rate and amount of stretch
- Causes muscle contraction
126
How does static stretching a muscle affect the muscle spindle?
By contracting the muscle to improve flexibility
127
How long is recommended to hold a static stretch? Why?
10-15 seconds because it allows the muscle spindle to fatigue
128
What is the goal of static stretching?
To fatigue the muscle spindles
129
How can you relieve a muscle cramp?
By stretching it
130
Why is the muscle spindle more active during a muscle cramp?
Because it is firing like crazy
131
Why might your stretch be impaired after you perform long duration stretching?
Because the muscle spindle is fatigued
132
Concentric contraction is enhanced because of:
1) Stretch Reflex
| 2) Elastic rebound of muscle
133
How can you improve vertical jump performance?
By doing box jumps
134
How can you enhance strength and power by doing a stretch reflex?
By doing a clap push-up
135
Why is the Golgi tendon organ activated?
To protect the muscle from injury as a result of forceful muscle contraction
136
How can you improve flexibility by stretching?
Inhibit Muscle spindle
| Activate Golgi tendon organ
137
How can you exert maximal power?
Inhibit Golgi tendon organ
| Activate muscle spindle
138
Training by using plyometrics allows you to:
- Increase your ability to activate the stretch reflex
- Increase your ability to use stored elastic energy from muscle
- Increase your ability to inhibit the Golgi tendon organ
139
What causes a muscle cramp during or after intense exercise?
- Abnormal activation of muscle spindle
- Electrolyte imbalances
- Dehydration
140
Bilateral Deficit: What is it?
The sum of the unilateral strengths is greater than bilateral strengths
141
Causes of Bilateral Deficit
- Inhibition at higher brain centers
- Sensory input from one limp causing inhibition on motor neuron innervating muscles of opposite limb
- Biomechanical factors
142
What happens with Bilateral Deficit?
- Disappears with bilateral training
| - Increases with unilateral training
143
A rower should use what kind of training?
Bilateral Contractions
144
How can a beginner weight training gain muscle mass fast?
By training with unilateral contractions
145
Cross Education: What is it?
- Neural phenomenon
- Increase in strength of untrained contralateral limb after unilateral training
- Hypertrophy of trained limb
146
Magnetic Resonance Imaging
Detects hemoglobin status change
147
How can you apply cross education with rehabilitation?
By training an uninjured limb and it would help to train your injured limb
148
Central Nervous System
Brain and Spinal Cord
149
Peripheral Nervous System
All nerves that extend from the brain and spin (GTO, spindles)
150
Afferent
Nerves that carry information to the central nervous system
151
Efferent
Nerves that carry information away from the central nervous system
152
3 Controls of Movements
1) Voluntary Movements
2) Reflexes
3) Rhythmic Movements
153
Voluntary Movements
- Muscle memory
- Integrated at cerebral cortex
ex) throwing a javelin
154
Reflexes
- Sensory input
- Involved in posture
- Modulated in higher-brain centers
ex) Regaining your balance after tripping
155
Rhythmic Movements
- Voluntary and reflex
- Initiated by cerebral cortex
- Sustained without input from brain
ex) Walking, running
156
Inhibitory
Type of feedback transmitted to the agonist motor neuron when the Golgi tendon organ is activated
157
Excitatory
Type of feedback transmitted to the antagonist motor neuron when the Golgi tendon organ is activated
158
Cerebellum
Involved in the fine tuning or coordination of movements
159
Cerebral Cortex
Involved in planning and initiation of movement
160
Proprioreceptors
Senses the position of your limbs
161
Brain Stem
```
-Located at the base of the brain
Involved in:
-Maintaining balance
-Focusing on sensory inputs
-Posture and hand-eye movements
```
162
Vestibular Receptors
Located in the inner ear
163
Afferent or Efferent: Your eyes transmit a signal to your brain about the position of a soccer ball
Afferent
164
Afferent or Efferent: Voluntary contraction of your biceps by recruitment of motor neurons in the spinal cord
Efferent
165
Afferent or Efferent: Golgi tendon is activated, sending inhibitory signal to the spinal cord
Afferent
166
Afferent or Efferent: Vestibular sensors send a message to your brain to correct your balance
Afferent
