Muscular system Flashcards
(195 cards)
1
Q
what are the two types of muscles
A
smooth and striated
2
Q
what type of muscle are skeletal and cardiac
A
striated
3
Q
what is the reason for the striation
A
sarcomere
4
Q
what is the order of organization of skeletal muscle
A
tendon –> muscle –> fascicles –> myofibers –> myofibrils –> filaments
5
Q
what is the outermost layer of the muscle
A
epimysium
6
Q
what is the outermost layer of the fascicles
A
perimysium
7
Q
what is the outermost layer of the muscle fiber/lays in between fibers
A
endomysium
8
Q
what is the distinct feature of the skeletal muscle
A
it it multi-nucleated
9
Q
why does the skeletal muscle cell have multiple nuclei
A
the myoblasts - which each have a nucleus fuse together to form the muscle cell
10
Q
why is the myofibril super long
A
the muscle cells fusing together
11
Q
what is the outermost contractile layer of the muscle fiber
A
sarcolemma
12
Q
what does the sarcolemma enclose
A
sarcoplasm
13
Q
what are T-tubules integrated through
A
sarcoplasm
14
Q
what travels through the T-tubules
A
action potentials
15
Q
what is the sarcoplasmic reticulum filled with
A
Calcium
16
Q
which receptors in the sarcoplasm are voltage gated
A
dihydropyridine
17
Q
what do ryanodine receptors do
A
they let Ca2+ pass through the sarcoplasmic reticulum (SR)
18
Q
what are myofibrils made of
A
sarcomeres
19
Q
what is the structural and functional unit of the striated muscle
A
sarcomere
20
Q
what makes the muscle contract (in the simplest term)
A
thin filaments sliding over the thick filaments
21
Q
what band causes dark bands
A
A bands
22
Q
what band causes light bands
A
I bands
23
Q
what is the A band
A
thick and thin filaments overlap
24
Q
what is the I band
A
thin filaments only
25
what is the M line
where all the thick filaments stem from/connect
26
what makes up the thick filament
myosin molecules
27
what characteristics does the myosin contain
2 heads and a tail
28
which way does the myosin tail face
toward the A band
29
how does the myosin "power stroke" forward
ATP binds and gives myosin head energy to move forward
30
when does myosin go forward
when it binds to actin
31
what are the thin filaments composed of
actin
32
what controls actin and myosin interactions
regulatory proteins
33
what is tropomyosin
a long protein that spans actin
34
what is it called when tropomyosin overlaps
head to tail overlap region
35
what protein is at the overlap region of the actin and myosin
troponin
36
what are the subunits of troponin
TnC, TnI, TnT
37
what does TnC do
binds calcium
38
TnI
inhibits by binding to actin to prevent myosin from binding
39
TnT
teathers TnC and TnI to tropomyosin
40
how will actin and myosin interact
there has to be changes in complex
41
What happens when calcium binds to TnC
hydrophobic pocket is revealed; TnI moves away and interacts with TnC instead of actin
42
what happens during structural changes of troponin complex
tropomyosin moves along actin which allows for actin and myosin to interact
43
what causes the cross bridge to move from blocked to just closed
Ca2+ binds to TnC
44
what causes tropomyosin to be pushed away
cross-bridges binding
45
what causes troponin complex to be moved to open state
cross bridges pushing tropomyosin further away
46
what causes weakly bound cross bridge to go to strongly bound
inorganic phosphate is released
47
what happens when myosin pulls back on actin (thin filament)
sarcomere contracts
47
what causes myosin and actin to detach
ATP kicks out ADP
48
where does an efferent neuron carry signals to and from
carries them from CNS to neuromuscular junction
49
what does the signal being carried to neuromuscular junction result in
depolarization
50
in excitation-contraction coupling what causes threshold to be reached
Na channels open
51
what do the vesicles contain in excitation contraction coupling
acetylcholine
52
in excitation-contraction coupling what causes the vesicle to release Ash
SNARE complex
53
what does the ACh travel through in excitation and relax. coupling
ligand-gated channels
54
in excitation-contraction coupling what does the binding of ACh cause
sodium enters muscle cell
55
in excitation-contraction coupling what does the influx of Na+ lead to in the cell
depolarization
56
in excitation-contraction coupling what causes Na+ channel to close
inactivation gate closes
57
in excitation-contraction coupling what channels open after Na+ channels close
K+ channels
58
in excitation-contraction coupling what is the result of K+ channels opening
K+ flows out which leads to rapid depolarization
59
in excitation-contraction coupling what causes hyperpolarization
K+ channels closing slowly
60
what activates the dihydropyridine receptors
action potential traveling down T-tubule
61
what do dihydropyridine receptor interacts with
ryanodine
62
what is the result of dihydropyridine receptors interacting with ryanodine receptors
Calcium is released from S.R.
63
What happens to calcium after it is released from S.R.
it binds to TnC in the troponin complex
64
what are the three things that cause sarcomere/muscle relaxation
ACh isn't present because it is broken down, myosin detaches from actin via ATP, calcium is moved back into SR via SERCA pump
65
main feature of smooth muscle
involuntary control
66
where is smooth muscle found
body cavities and blood vessels
67
what is the shape and size of smooth muscle
spindle and small
68
what is the difference in nuclei between smooth and striated
striated has multiple, smooth has one
69
what is the main difference in strained and smooth muscle
smooth doesn't have sarcomeres, t-tubules, myofibrils, etc.
70
how are thick filaments organized in smooth muscle
they're scattered
71
where do thin and thick filament overlap
dense bodies
72
how does smooth muscle contract without sarcomeres
thick and thin filaments slide over each other
73
how does the entire tissue contract
one muscle cell pulls on the neighboring one
74
what are bulges in smooth muscle called
varocosities
75
where are the bulges in smooth muscle found
in axons that innervate smooth muscle cells
76
what do ligand gated channels in smooth muscle activate
voltage gated calcium channels
77
what do the neurotransmitters from the varicosities bind to
ligand gates ion channels
78
what does the opening of voltage gates Ca2+ channels in smooth muscle result in
Calcium moves in to smooth muscle cells --> contraction
79
two types of smooth muscle cells
multiunit and visceral (single unit)
80
how do multiunit smooth muscle cells work
each motor neuron innervates its own smooth muscle cell
81
how does a single unit smooth muscle cell work
motor neuron innervates just one cell
82
how are multiunit smooth m. cells regulated
by hormones ex) fight or flight
83
where are single unit smooth m. cells found
digestive/urinary tract
84
what are single unit smooth m. cells activated by
stretch
85
main similarity of cardiac muscle and skeletal muscle
myofibrils causing striation
86
differences of cardiac and skeletal muscle
cardiac muscle is smaller
87
what is the purpose of the cardiac muscle being small and branched
allows heart to contract and relax as a single unit
88
how are cardiomyocytes linked
intercalated discs
89
what are the types of cell junctions in intercalated discs
gap junctions and desmosomes
90
types of cells in the heart
contractile cells and autorhythmic cells
90
what is the purpose of desmosomes
mechanical support (destiny wants to be a mechanical engineer)
91
how does an AP move down heart
through contractile cells to gap junctions which results in contraction
92
what ion has a higher concentration inside the cell
K+ - which is why it leaves the cell during depolarization
93
types of metabolism
catabolism and anabolism
94
what is it called when molecules are broken down to extract energy
catabolism
95
what is it called when metabolic reactions synthesize building blocks to make new molecules
anabolism
96
what is the stored energy in muscles called
glycogen
97
what is the equation for photosynthesis
CO2 + water + energy from sun --> carbs + O2
98
where is chemical energy contained in photosynthesis
between bonds of atoms
99
what is the main idea of how our bodies get energy
they extract it from the carbon bonds to make ATP
100
what phosphate does ATP come from
The third/last phosphate
101
4 main pathways our body gets energy
glycolysis, pyruvate to acetyl coa, citric acid cycle, electron transport chain
102
what is glucose splitting
6-carbon glucose splits into two 3-carbon pyruvate molecules
103
what is the end products of glycolysis
2 pyruvate molecules and 4 ATP molecules
104
how many carbon atoms does pyruvate have
3
105
where does glycolysis take place
cytosol
106
what are the anaerobic pathways
glycolysis and pyruvate to acetyl coa or lactate
107
what does glycolysis require to take place
2 ATP molecules
108
what picks up electrons in glycolysis
NADH+
109
what can pyruvate convert to
acetyl CoA or lactate
110
what determines what pyruvate is converted into
amount of O2 available
111
where is lactate taken
liver
112
what happens to lactate in the liver
it's converted back into glucose
113
how much net ATP is generated when glucose converts to pyruvate
2 ATP
114
what does pyruvate convert to when oxygen is available
acetyl CoA
115
how many acetyl coa molecules are produced from the 2 pyruvate from glycolysis
2 molecules
116
What happens to the 3 carbons in pyruvate
1 goes towards CO2 and the other 2 are linked to co-enzyme A to form acetyl CoA
117
what do the carbons from pyruvate bind with to make acetyl CoA
enzyme A
118
what is the substrate and also an end product of the citric acid cycle
oxaloacetate
119
what happens to the carbons in the citric acid cycle
the two from acetyl CoA bind with 4 from oxaloacetate to form 6 in citric acid
120
what happens to the 2 carbons that moved from acetyl CoA to citric acid
the convert to CO2
121
what does the citric acid cycle produce
GTP, 1 ATP, 1 NADH, 2 FADH, oxaloacetate (regenerated)
122
how many times does the critic acid cycle occur
2 times
123
why does the critic acid cycle occur twice
because it starts with ONE acetyl CoA but glycolysis makes two pyruvate which makes TWO acetyl CoA
124
what depletes the electrons of energy in the ETC
oxygen baskets
125
What does oxygen do in the ETC
picks up E- and combines with H+ to make water
126
what would happen if there wasn't O2 in the ETC
ATP production would stop
127
how many complexes does the ETC have
4
128
where does NADH give its electrons to
complex 1
129
where does FADH2 give its electrons to
complex 2
130
how do electrons move energy levels when being passed down the ETC
they move from higher to lower energy levels as they release energy
131
how does H+ move into inter membrane space
as e- move from one complex to another, they pump H+ through
132
how does the electrochemical gradient occur
H+ being moved into intermembrane space means higher concentration of H+
133
what does the electrochemical gradient do to H+ ions
it moves it back into matrix
134
how do the H+ ions get back into matrix
atp synthase
135
what happens once H+ ions move back into matrix
they bond with O2 to make H2O
136
what is happening to the ATP synthase as H+ ions move through it
it rotates
137
what does the rotation of ATP synthase cause to happen
creates binding sites for ADP to bind to Pi to make ATP
138
what is the structure of lipids
glycerol backbone (3 carbon), each carbon is linked to a fatty acid
139
what is the function of lipase
breaks down glycerol backbone in to the 3 carbons
140
what happens to the 3 carbons that were broken down by lipase
they can enter glycolysis
141
what happens to the fatty acids that were broken down by lipase
they can be converted into acetyl-CoA
142
what is it called when acetyl CoA is made from fatty acids
beta oxidation
143
where does beta oxidation take place
mitochondria
144
what happens to the two end carbons that are cut off in beta oxidation
they link with CoA to make acetyl CoA
145
how does beta oxidation fuel ATP synthesis
acetyl-CoA enters critic acid cycle which goes to ETC
146
what is the function of carnitine
transports FFA across mitochondrial membrane to beta oxidation
147
when does the body make energy from proteins
starvation
148
what are proteins broken down into
amino acids
149
what happens to the amino group
deamination - strips off amino acid
150
what is left after deamination
carbon skeleton
151
what does the carbon skeleton enter
catabolic pathway
152
what determines how much ATP is created by the carbon skeleton
what pathway it enters
153
what does the breakdown of amino acids yield
urea, CO2, water, and ATP
154
How do we know what nutrient is being used to generate ATP
respiratory quotient
155
what is the equation for RQ
CO2 exhaled / O2 being used
156
what are the RQ values for the nutrients
carbs - 1, pro - 0.8, fat - 0.7
157
why does pro and fat have a smaller RQ
they require more O2 to make CO2 and water = denominator is smaller
158
how is creatine phosphate made
via amino acids
159
where is creatine phosphate created, stored, and excreted
made in the liver, stored in the muscles, excreted in the kidneys
160
what do the kidneys excrete in the creatine phosphate system
creatinine
161
what fuel are you using during rest
carbs and fat
162
what fuel are you using during an initial burst
creatine phosphate
163
what fuel are you using during anaerobic
carbs
164
what are you doing if your RQ level is at 0.8
resting
165
what type of muscle fiber for long distance
slow fibers
166
what type of muscle fiber for a sprint
fast fibers
167
167
what differentiates muscle fibers
size, blood vessels, how fuel is used, contraction speed, fatigue resistance
168
where does myoglobin mostly store O2
slow fibers
169
how to change muscle fibers
conditioning or genetics
170
what muscle fibers are in white meat
fast fibers to flee predators
170
what muscle fibers are in red meat
slow fibers to stand around
171
what is it called when the muscle can't perform any longer
muscle fatigue
172
what is the main reason for muscle fatigue
metabolic reserves are depleted
173
what are some characteristics of muscle fatigue
increase in lactic acid, decrease in enzyme activity (acetyl coa binding), decreases in Ca2+ binding to TnC
174
what are the 3 reasons for DOMS
1. tears in muscle tissue = loss of enzymes
2. muscle spasms
3. CT and tendon tears
175
what helps doms
stretching
176
what happens to muscle fibers as we age
decrease in size, elasticity, ability to recover
177
two main types of muscle contraction
isotonic and isometric
178
what are the two types of isotonic muscle contraction
concentric and and eccentric
179
how can we change the force produced by muscle
recruitment of motor units, twitch summation, force-length relationship
180
what is a motor unit
a motor neuron and all the fibers it innervates
181
characteristics of small motor units
few myofibers, slow twitch, fatigue resistant
182
characteristics of large motor units
few myofibers, fast twitch, fatigues quickly
183
why does force go back down in between twitches
Ca2+ goes back in to S.R.
184
what happens when the cardiac muscle is first stimulated
Na+ channels open causing depolarization
185
what causes plateau in cardiac muscle action potential
Ca2+ influx balanced by K+ efflux
186
what leads to repolarization of cardiac muscle action potential
K+ efflux and Ca2+ channels close
187
which muscle experiences summation
skeletal, not cardiac
188
what is force generated proportional to
of actin and myosin interactions
189
what limb does cardiac muscle experience force
ascending
190
what limb does skeletal muscle experience force
plateau
191
what type of muscle experiences a more dramatic increase in force with a sarcomere length change
cardiac - because the muscle is smaller
