Unit 3 Muscles Flashcards
1
Q
Groups of muscle are covered by…
A
deep fascia
2
Q
Muscle is covered by…
A
epimysium
3
Q
Fascicle is covered by…
A
perimysium
4
Q
Muscle fiber is covered by…
A
endomysium
5
Q
Which cells do muscle “fibers” arise from?
A
Myoblasts
6
Q
Hypertrophy
A
Increase in size
7
Q
Hyperplasia
A
Increase in number
8
Q
Can muscle fibers undergo mitosis?
A
No
9
Q
What performs the conduction of electrical signals?
A
Sarcolemma
10
Q
What controls muscle contraction?
A
Sacroplasmic reticulum
11
Q
What allows for muscle contraction?
A
Myofibrils inside muscle fibers
12
Q
Longitudinal bundles of protein filaments inside the muscle fiber
A
Actin and Myosin
13
Q
Highly organized into repeating units
A
Sarcomeres
14
Q
Contractile proteins
A
Actin and myosin
15
Q
Regulatory proteins
A
Troponin and tropomyosin
16
Q
Actin
A
- found in thin filaments
- has myosin binding sites for crossbridge formation
17
Q
Myosin
A
- motor protein found in thick filaments
- head of myosin binds to the binding site on actin during muscle contraction
18
Q
In which filament is actin found?
A
thin
19
Q
In which filament is myosin found?
A
thick
20
Q
Which part of myosin binds to the actin binding cite?
A
the head
21
Q
Sarcomeres
A
Functional unit of contraction
22
Q
The binding site on actin is covered by what?
A
regulatory proteins
23
Q
Which muscle protein gives muscles elasticity and extensibility?
A
Titin
24
Q
Which muscle protein helps the sarcomere return to its resting length?
A
Titin
25
What is a cytoskeletal protein that links thin filaments to the sarcolemma?
Dystrophin
26
Which muscle protein is attached to the extracellular proteins in the connective tissues surrounding the muscle fibers?
Dystrophin
27
Which muscle protein helps transmit tension from sarcomeres to tendons?
Dystrophin
28
Which muscle protein spans the length of the thin filament?
Nebulin
29
Which muscle protein anchors thin filaments to Z disc?
Nebulin
30
Which muscle protein is found in the Z disc?
α-actinin
31
Which muscle protein binds to actin molecules of the thin filament to titin?
α-actinin
32
Which muscle protein is found in the M line?
myomesin
33
Which muscle protein binds titin and thick filament to connect them together at the M line?
Myomesin
34
Myosin heads bind to actin to form a ________
crossbridge
35
Conformational change is energized by ________ to cause thin filaments to slide along thick filaments
ATP hydrolysis
36
As thick / thin filament overlap increases....
I band length decreases
A band length remains constant
H zone length decreases
Zone of overlap increases
37
the attached head group after the power stroke is called a _______
Rigor complex
38
Rigor mortis
the rigor of death because lack of ATP to detach the crossbridge
39
Functions of skeletal muscle
- locomotion
- facial expression
- heat production
40
Function of cardiac muscle
pump blood into systemic circulation
41
Functions of smooth muscle
- propel food
| - mix food
42
The immediate source of energy to support development of tension
ATP
43
Hydrolysis by the myosin head group fuels _________
tension generation
44
Hydrolysis by the Ca-pump of the SR supports ________
relaxation
45
What are three ways ATP re-synthesizes?
1. creatine phosphate
2. anaerobic glycolysis
3. aerobic metabolism
46
How long does ATP support force?
2 seconds
47
How long does creatine phosphate support force?
15 seconds
48
Creatine phosphate pool after a meal
ATP + C --> ADP + CP
49
Creatine phosphate pool during exercise
ADP + CP --> ATP + C
50
Small amino acid-like molecule
Creatine
51
Where is creatine synthesized?
Liver, kidney, and pancreas
52
Where is creatine transported?
Muscle fibers
53
In a relaxed muscle fiber what is 3-6x more plentiful than ATP
Creatine phosphate
54
How long does glycolysis support force?
2 minutes
55
Where does glycolysis occur?
Rapidly, cytoplasm
56
How long does aerobic respiration support contraction?
40 minutes to several hours
57
Fatigue is caused by
- glycogen depletion
- lactic acid buildup
- phosphate buildup from creatine phosphate metabolism
- potassium accumulation
58
What structural muscle protein spans the z disc to m line
Titin
59
Which structural protein stabilizes thick filament?
titin
60
Which muscle protein gives muscle its elasticity and extensibility?
Titin
61
Which structural muscle protein helps the sarcomere return to its resting length?
Titin
62
Which regulatory proteins are found in thin filaments?
Tropomyosin and troponin
63
Which regulatory protein covers the myosin binding sites on actin?
Tropomyosin
64
Which regulatory protein holds tropomyosin in place?
Troponin
65
During muscle contraction, what binds to troponin?
Calcium
66
Contraction cycle
1. Binding sites exposed
2. Myosin heads bind (crossbridges)
3. Myosin heads pivot
4. ATP binds --> detachment
5. ATP Hydrolyzed
BCMDH
67
Excitation
Electrical signal from neuron to muscle fiber
68
Excitation Contraction Coupling
Releases CA from SR
69
Contraction
Crossbridges form
70
Relaxation
removal of Ca
71
Pyruvic acid turns into what during anaerbic glycolysis
Lactic acid
72
At rest, myosin heads cannot bind because
Tropomyosin is covering the binding sites on actin
73
When ATP is hydrolyzed by the myosin ATPase, which immediate step occurs
The myosin head moves into a cocked position
74
In the cori cycle, lactic acid...
is converted into glucose in liver cells
75
Tetanus (tetanic contraction)
summation of individual twitches over time
76
Mechanism for increasing tension
Tetanus (temporal summation) is a mechanism for increasing tension
77
Motor Unit
A motor neuron and all of the muscle fibers it innervates
78
Spatial Summation
Activating increasing numbers of motor units to increase tension
79
The first motor units recruited are...
small
| innervate few fibers
80
As more force is required activate fibers...
larger motor units are recruited
81
Motor united are recruited in order from...
small to large
82
Standing required what size motor units?
Smallest motor units
83
Sprinting and jumping require what sized motor units?
Large to largest
84
Isometric means ...
same length
85
During isometric contraction ...
muscle generates tension but does not shorten
86
every contraction begins ...
isometrically
87
Isotonic means ...
same tension
88
During isotonic contraction ...
after sufficient tension is generated to move the load, the muscle changes length
89
What does creatine phosphate donate to?
Donates a phosphate to ADP to create ATP
90
Lactic acid can be transformed back into glucose where?
Liver
91
What does lactic acid inhibit
Glycolysis
92
Pyruvate --> lactic acid
anaerobic
93
pyruvate --> mitochondria
aerobic
94
How will capillary density change during exercise?
Increase
95
How does mitochondrial density change from exercise?
Increase
96
How does the cross sectional area change from exercise?
Increase
97
How long does increased capillary density take?
3-4 weeks
98
Increased mitochondria help improve...
aerobic capacity
99
How fast do slow fibers contract?
Slowly
100
Are small fibers slow in diameter?
no
101
What type of metabolism do slow fibers use?
Aerobic
102
What metabolism do fast fibers use?
Anaerobic
103
How fast do intermediate fibers move?
Relatively fast
104
What metabolism do intermediate fibers use?
Primarily anaerobic
105
Within a motor unit all the fibers are...
the same type
106
Slow fibers are which type
Type I
107
Type I fibers
1. Low ATPase speed
| 2. High resistance to fatigue
108
Slow oxidative type I fibers rely on which metabolism
aerobic
109
Slow oxidative fibers have a ____ myoglobin content
high
110
Slow oxidative fibers have a ____ capillary supply
dense (for O2)
111
Myoglobin is a protein that carries ______ through the cell
oxygen
112
Fast- glycolytic IIb fibers
1. High ATPase speed
| 2. Low resistance to fatigue
113
FG type IIb fibers rely on what metabolism?
anaerobic glycolysis
114
FG IIb fibers have _____ mitochondria
few
115
FG IIb fibers have _____ myoglobin content
low
116
FG IIb fibers have ______ glycolytic enzyme content
high
117
FG IIb has _____ creatine kinase content
high
118
Glycolytic and cratine kinase enzymes are used for
anaerobic
119
Intermediate, fast oxidative glycolytic, Type IIa fibers
1. Moderate ATPase speed
| 2. Intermediate resistance to fatigue
120
FOG type IIa fibers rely on what metabolism?
glycolysis but have a higher aerobic capacity compared to IIb
121
Myoglobin contains _____ that allows it to bind to oxygen
heme (iron)
122
What is responsible for muscles red color?
myoglobin
123
Slow oxidative fibers have more fat because
they have better aerobic respiration
124
Latent period can be compared to...
excitement- contraction coupling with no tension development
125
The more calcium is present.....
the more crossbridges form
126
The eye muscles twitch at which speed?
Fast twitch
127
What is the time course for the soleus?
Slow twitch
128
Muscles that slow twitch are more for which purposes....
posture
129
In a second class lever
the load is between the fulcrum and the effort
130
Nodding your head yes involves
flexion of the head at the first class lever
131
ATP binds to the myosin head and causes
the detachment of myosin from actin
132
The type of contraction that generates tension while they lengthen
eccentric
133
In skeletal muscle, what acts as ATPase during the contraction cycle?
myosin head groups
134
Characterization for intercalated discs
cardiac muscle
135
characterization for numerous large mitochondria
cardiac muscle
136
Which muscle allows for tubes like blood vessels to change in diameter?
smooth muscle
137
In which contraction is the effort greater than the load
Concentric
138
What are two common muscle themes?
Sliding filament
| Regulation of cytoplasmic Ca
139
Cardiac muscles compared to skeletal muscles have a _____ extensive T-tubule and SR system
less
140
gap junctions are...
channels that allow signals to pass between cells
141
Desmosomes help to...
keep cardiac cells together
142
For cardiac muscle SR Ca...
is not enough to support contraction
143
What initiates cardiac muscle contraction?
Cardiac muscle has its own signal... not the nervous system
144
Autorhythmicty
pacemaker cells ---> generation of APs
145
Cardiac muscle cells have no _____ ________
motor units
145
Cardiac muscle cells have no _____ ________
motor units
146
Twitch
the response of the cell of one electrical signal
147
Every cardiac muscle contraction is considered a _______
twitch
148
In skeletal muscle it is considered _______ not twitches
tetanus
149
Describe smooth muscles nucleus
small single nuclei
150
Describe the structure of smooth muscle
lacks a clearly organized structure
151
Does smooth muscle have sarcomeres
no
152
Describe smooth muscle t-tubule/SR system
has none
153
In smooth muscle Ca DOES NOT interact with....
regulatory proteins
154
In smooth muscle contraction what does Ca bind to
calmodulin
