muscles Flashcards
1
Q
What happens to a muscle when it is used? (4)
A
gets larger, stronger, more resistant to fatigue and more efficient
2
Q
What happens to a muscle when it is not used? (2)
A
muscle weakness and atrophy (wasting)
3
Q
Give 4 common examples of aerobic or endurance exercises.
A
walking, jogging, biking and swimming
4
Q
Give 3 changes that happen to a muscle when a person does aerobic or endurance exercises.
A
more capillaries, more mitochondria, and more myoglobin
5
Q
What type of exercise results in muscle hypertrophy?
A
high intensity, resistance exercise
6
Q
Give 2 common examples of resistance exercise.
A
weight lifting - low rep and heavy or isometric exercises
7
Q
What happens within a muscle to make muscles hypertrophy?
A
increased size of individual fibers - more myofibrils, more mitochondria, more glycogenalso increased CT between fibers (possibly some splitting or tearing and regrowth using satellite cells - controversial)
8
Q
What is a common term for someone who doesen’t work antagonistic muscle pairs evenly and they become awkward and inflexible?
A
muscle-bound
9
Q
Why should a hard workout be followed by a day of rest?
A
to prevent overuse injuries
10
Q
a degeneration and loss of mass in muscles from inactivity
A
disuse atrophy
11
Q
How much muscle strength can be lost each day with disuse atrophy?
A
5% per day
12
Q
What is lost or damaged muscle tissue replaced with?
A
fibrous CT - scar tissue
13
Q
What are the 4 factors that determine the force of a muscle contraction?
A
- number of fibers
- size of the fibers
- frequency of stimulation
- degree of muscle stretch
14
Q
What is the term for an enlargement of a muscle?
A
hypertrophy
15
Q
What is the term for the force generated by the cross bridges in a muscle?
A
internal tension
16
Q
What is the term for the force generated on the load or resistance by the entire muscle at the insertion?
A
external tension
17
Q
What is the term for an increase in the force of contraction due to an increased frequency of stimulation?
A
summation of twitches or wave summation
18
Q
the degree of overlap between thick and thin myofilaments can permit more or less sliding and therefore more or less force
A
length-tension relationship
19
Q
What are two ways muscle fibers are classified?
A
- speed of contraction
2. how they make ATP
20
Q
What are the two main types of fibers based upon speed of contraction, and what makes them different speeds?
A
fast twitch - ATPase works fast and Ca2+ is pumped quickly
slow twitch - ATPase works more slowly and Ca2+ isn’t pumped as quickly
21
Q
What do we call the fibers that rely more on oxygen and aerobic respiration?
A
oxidative fibers
22
Q
What do we call the fibers that rely more on anaerobic respiration?
A
glycolytic fibers
23
Q
What are the three types of fibers based upon both speed and ATP generation?
A
slow oxidative
fast oxidative
fast glycolytic
24
Q
Which muscle fiber is resistant to fatigue and has a high endurance but not a lot of power?
A
slow oxidative
25
Which muscle fiber tires quickly but has power?
fast glycolytic
26
Which muscle fiber is the most rare and has some traits of the other two?
fast oxidative (intermediate)
27
What determines which fibers predominate in a muscle?
Most muscles are mixtures that are genetically determined but can be altered by conditioning.
28
Who needs more fast glycolytic fibers, a marathon runner or sprinter?
sprinter
29
Who needs more slow oxidative fibers, a marathon runner or a sprinter?
marathoner
30
What is another name for the resistance to contraction?
load
31
How does load affect contraction speed?
more load makes contraction slower.
32
the inability to contract even when the muscle receives stimuli
fatigue
33
states of continuous contractions because the crossbridges don't detatch when there is no ATO
contractures
34
What is a common example of a contracture that most people have experienced?
writer's cramp
35
How long can a typical muscle work on its ATP reserves?
4-6 seconds
36
What is ATP?
adenosine triphosphate, usable energy in a cell made by respiration, the only energy used directly for cell activities
37
After the stored ATP is used, what are three ways it can be regenerated?
1. creatine phosphate rephosphorylating ADP
2. glygolysis (anaerobic respiration)
3. aerobic respiration
38
a high energy molecule that stores phosphate to quickly phosphorylate ADP to ATP
CP - creatine phosphate
39
How much CP can be stored in a muscle? How long will the CP stored in a muscle last?
Muscle cells can store 2-3 times as much CP as ATP. It will last an additional 10 seconds for a total of 14-16 seconds with the ATP stored.
40
what is the term for the initial breakdown of glucose? What is glucose broken into? How much energy is produced?
glycolysis - 2 pyruvic acids makes 2 ATP
41
What is the difference between aerobic and anaerobic respiration?
aerobic uses oxygen and is more efficient (makes more energy or ATP) Aerobic is slower than anaerobic
42
What about muscle activity slows oxygen delivery?
Bulging muscles compress blood vessels.
43
What is the byproduct of anaerobic respiration, and what does it do to muscles?
lactic acid makes muscles tired and sore - some muscles are more tolerant of lactic acid buildup
44
What is the advantage of anaerobic respiration?
It is faster so when large amounts of energy are needed in a short time, it works best.
45
Where in the muscle does anaerobic respiration occur?
cytoplasm
46
Where in the muscle does aerobic respiration occur?
mitochondrion
47
What are the chemical products of aerobic respiration? How much energy is made?
carbon dioxide and water and 32 ATP per glucose
48
When exercise demands exceed the ability of muscle a muscle to do reactions to keep it supplied with energy and the muscle converts to anaerobic glycolysis, what has been reached?
anaerobic threshold
49
What three things must occur for a muscle to recover?
1. breathe hard to recycle lactic acid and pay back the oxygen debt
2. sweat to release excess heat
3. pump ions like sodium, potassium, and calcium back to their resting locations
50
How is the CT component of smooth muscle different from that of skeletal muscle?
Smooth has much less CT, just a little endomysium
51
What are the two layers of smooth muscle? What does each do?
longitudinal - shortens and dilates the organand circular lengthens and constricts the organ
Together they mix and push materials through the lumen.
52
What is the name for the propulsive movement of smooth muscle?
peristalsis
53
What is the result of unwanted smooth muscle contraction in the stomach? the airways?
cramping - asthma
54
What portion of the nervous system innervates smooth muscle?
autonomic
55
How are the connections between autonomic fibers and smooth muscle different from the neuromuscular junctions of motor neurons and skeletal muscles? Give 5 differences.
called diffuse junctions
1. numerous varicosities -large bulbous swellings
2. wide cleft
3. less developed SR
4. no t-tubules - caveolae instead
5. calcium comes from caveolae not SR
56
Give 6 ways smooth muscle is different from skeletal muscle.
1. no striations
2. no sarcomeres
3. fewer thick myofilaments but they have myosin heads along their entire length so it can still be as powerful
4. no troponin complex - calmodulin instead
5. thick and thin myofilaments are arranged diagonally - spiral
6. have non-contractile intermediate filaments with dense bodies attached to sarcolemma
57
How is the contraction of smooth muscle different from that of skeletal muscle? Give 7 ways
1. slower - 30 times longer
2. synchronized by gap junctions
3. some cells act as pacemakers and set the rythm
4. self-excitatory but can be modified by nerves and hormones
5. can last much longer with much less energy used
6. uses different neurotransmitters with different outcomes
7. can contract without neural stimulation at all
58
How is the contraction of smooth muscle similar to the contraction of skeletal muscle? Give 3 ways.
1. sliding filaments of actin and myosin
2. calcium is the trigger
3. ATP provides the energy
59
Sarcoplasmic Reticulum
The ER of a muscle cell or fiber
60
Skeletal muscle
Cylindrical, multinucleate, striated, voluntary muscle found attached to bones
61
Sliding filament theory
The explanation of how muscle contracts, think myofilaments pull and slide along thin myofilaments
62
Smooth muscle
Fusiform (tapered at both ends), uninucleate, non-striated, involuntary muscle found in hollow internal structures that move other than the heart
63
Striated
Banded or striped in appearance due to alteration of thick and thin filaments
64
the study of muscles
myology
65
the four characteristics of muscle
contractility, excitability, elasticity, extensibility
66
the ability of a muscle to shorten
contractility
67
the ability of a muscle to respond to a nerve
excitability
68
the ability of a muscle to stretch
extensibility
69
the recoil ability of muscle to snap back to its original position
elasticity
70
the muscles that work in opposition to one another - give examples
antagonists - biceps and triceps and quadriceps and hamstrings
71
the striped or banded appearance of some muscle tissue
striations
72
What causes muscle to appear striated
alternating thick and thin myofilaments
73
the protein that builds thick myofilaments
myosin
74
What is the shape of a myosin molecule
golf club
75
the protein that builds the majority of the thin myofilaments
actin
76
What is the shape of the actin molecule?
G actin - globular (spherical)
| F actin - filaments (threads) of G actin
77
What are the two regulatory proteins on the thin myofilaments?
troponin and tropomyosin
78
Which regulatory protein is the site of calcium binding?
troponin
79
What happens when calcium lands on the troponin?
The troponin bends and moves the tropomyosin
80
the contractile unit of skeletal muscle, goes from z-line to z-line
sarcomere
81
the line of protein fibers that holds thick myofilaments together
M-line
82
the protein filaments that hold the thin myofilaments together
Z-line
83
the length of the thick myofilaments, darker
A band
84
the region between the thick myofilaments
I band
85
the elastic protein that holds the thick myofilaments to the Z-line
titin
86
the lighter region of the A band on either side of the M-line
H-zone
87
the three different types of muscle tissue
skeletal cardiac and smooth
88
the muscle tissue with long cylindrical, striated, multinucleate fibers - attached to bone and voluntary
skeletal muscle
89
the muscle tissue with branched, striated, uninucleate cells - involuntary with intercalated discs and gap junctions
cardiac muscle
90
the torpedo shaped, involuntary, uninucleate muscle cells with gap junctions
smooth muscle
91
large movements
gross
92
small, precise movements
fine
93
Give 5 functions of muscle.
1. produce movement
2. posture
3. guarding entrances and exits
4. produce body heat
5. support soft tissue
94
What percent of the body heat is produced by skeletal muscles?
85%
95
a sheet of fibrous CT directly beneath the skin
superficial fascia
96
a layer of CT around muscles and organs
deep fascia
97
the outer layer of CT around the entire skeletal muscle
epimysium
98
the innerlayer of CT around individual muscle fibers
endomysium
99
a bundle of muscle fibers
fascicle
100
the CT layer around the fascicles
perimysium
101
an immature muscle cell that fuses
myoblast
102
a myoblast that doesn't fuse - what is the purpose
satellite cells - healing
103
the cell membrane of a muscle fiber
sarcolemma
104
the cytoplasm of a muscle fiber
sarcoplasm
105
the ER of a muscle fiber
sarcoplasmic reticulum
106
the expanded tubes of SR that store calcium for muscle contraction
terminal cisternae
107
the tubes that go perpendicularly from the sarcolemma deeper into the muscle fiber
t-tubule
108
2 terminal cisterns and 1 t-tubule
triad
109
when a muscle grows directly into the periosteum
direct attachment
110
when a muscle is connected to a bone by a tendon or aponeurosis
indirect attachment
111
What is the difference between a tendon and an aponeurosis?
tendon - a cord
| aponeurosis - a sheet-like tendon
112
a tube of synovial membrane and fluid through which a tendon slides
tendon sheath
113
a condition created by repetitive movements of the wrist, the wrist tendons swell and crush the median nerve
carpal tunnel syndrome
114
a connection between a nerve and a muscle
neuromuscular junction
115
another name for a nruromuscular junction
myoneural
116
the gap between a nerve and another nerve or muscle
synaptic cleft
117
the chemicals that communicate for nerves
neurotransmitters
118
the neurotransmitter that works on skeletal muscle
ACh acetylcholine
119
the enzyme that breacks down acetylcholine
AChE acetylcholinesterase
120
the sacks that hold neurotransmitter chemicals
synaptic vesicles
121
the feature that increases the surface area of the sarcolemma
junctional folds
122
the enlarged end of the nerve where it attaches to the muscle
synaptic knob or synaptic bulb
123
the ion that enters the synaptic knob to trigger the release of ACh
calcium
124
the organelle in a muscle fiber that is made of thick and thin myofilaments arranged in units called sarcomeres
myofibril
125
the idea that explains how muscles contract by thick and thin fibers moving past one another
sliding filament theory
126
the region of a sarcomere where there are both thick and thin myofilaments are found
zone of overlap
127
the place on the myosin that reaches out to grap the thin filament
cross bridge or myosin head
128
a group of inherited diseases where the muscle fibers are built improperly causing progressive muscular weakness
muscular dystrophy
129
the most common type of muscular dystrophy
Duchenne
130
the nerve that sends messages to a skeletal muscle
motor neuron
131
the place on the sarcolemma where the nerve meets up to it
motor end plate
132
when there is a difference in charge across a muscle cell membrane
polarized
133
the nerve message
action potential
134
when the muscle cell membrane loses its charge difference
depolarization
135
the active transport system that created the charge difference by pumping ions across the membrane
sodium-potassium pump
136
when the membrane is restored to its orignal state of charge difference
repolarization
137
the period of time it takes for the membrane to get back to its original state when it can't respond
refractory period
138
a single contraction/relaxation sequence caused by one action potential
muscle twitch
139
a graph of a muscle contraction
myogram
140
the period where the muscle builds tension
contraction phase
141
the period where the muscle loses tension
relaxation
142
the period on a myogram where the muscle can't respond
latent period
143
What is necessary for the cross bridges to relax?
ATP
144
Whar happens after death due to a lack of ATP
rigor mortis
145
food poisoning that prevents the release of ACh
botulism
146
an inherited autoimmune condition where the ACh receptors are damaged
myasthenia gravis
147
one motor neuron and all the muscle fibers it innervates
motor unit
148
getting more motor units involved to have a stronger contraction
recruitment
149
firm muscles because some fibers are contracted at any given time
muscle tone
150
when a muscle fiber is stimulated, it contracts completely or not at all
all-or-none principle
151
muscle fibers with power but little endurance
fast glycolytic fibers
152
muscle fibers with endurance but not much power
slow oxidative fibers
153
intermediate fibers with some power and some endurance
fast oxidative fibers
154
variations in the degree of contraction that allows for muscle control
graded muscle response
155
when muscle tension climbs due to receiving additional stimuli before relaxation
wave summation
156
when a contraction reaches maximal tension but still allows some relaxation
incomplete (unfused) tetanus
157
when a muscle contraction reaches maximal tension without any sign of relaxation
complete (fused) tetanus
158
the minimum stimulus necessary to cause a response
threshold stimulus
159
any stimulus that is lower than what is needed to cause a response
subthreshold stimulus
160
a bacterial infection that causes sustained muscle contractions
tetanus
161
what kind of bacteria causes tetanus and what kind of wound results in these bacteria
anaerobic - puncture wound
162
one end of a muscle on the less movable bone
origin
163
one end of a muscle on the more movable bone
insertion
164
what a muscle does
action
165
the nerve supply for a muscle
innervation
166
a contraction that actually shortens a muscle
isotonic
167
a contraction that can't shorten a muscle
isometric
168
an isotonic contraction that shortens a muscle
concentric
169
an isotonic contraction that lengthens a muscle
eccentric
170
three factors that help a muscle return to its original position
1. gravity
2. elasticity
3. opposing muscles
171
stored glycogen in muscles
glycosomes
172
the chemical that glucose splits into by glycolysis
pyruvic acid
173
the chemical that stores oxygen in muscles
myoglobin
174
how long a muscle lasts
endurance
175
how much tension a muscle can create
power
176
What determines how fast a muscle fiber can contract
the myosin ATPases
177
Which muscle fibers are called white meat, and which are called dark meat?
white meat - no blood, - powerful but less endurance
| dark meat - good blood supply - more endurance but less power
178
the opposing force to muscle tension, what tension has to overcome to cause movement
load
179
What determines the types of muscle fibers in a muscle?
genetics
180
the enlargement of a muscle
hypertrophy
181
What kind of exercise causes muscles to hypertrophy?
resistance exercise
182
the replacement of muscle with scar tissue
fibrosis
183
Furrows brow
Frontalis
184
Blinking muscle
Orbicularius oculi
185
Kissing muscle
Orbicularius oris
186
Smiling muscle
Zygomaticus
187
Tenses lip
Orbicularius oris
188
Frowning muscle
Depressor anguli oris
189
Muscle needed to play a horn
Buccinator
190
Flares nostrils
Nasalis
191
Raises upper lip
Levator labii
192
Whistling muscle
Buccinator
193
Chewing muscle
Massetor
194
Synergist for chewing
Temporalis
195
Moves tongue
Glossal
196
Opens jaw
Digastric
197
Swallowing muscle
Mylohyoid
198
Flexes neck or turns it side to side
Sternocleidomastoid
199
Below the hyoid
Infrahyoid
200
What do the pharyngeal constrictors allow?
Swallowing
201
What is good posture a result of?
Equal contraction of back muscles
202
How are abdominal muscles named?
By the direction their fibers run
203
Abducting arm muscles
Trapezius and deltoid
204
Adducting arm muscles
Lattisimus dorsi and terres muscles
205
Shrugging muscle
Levator scapuli
206
Knee flexor
Hamstring
207
Knee extensor
Quadriceps
208
Allows you to sit cross-legged
Sartorius
209
Abducting muscle of leg
Tensor fascai late
210
Adducting muscle of leg
Adductors
211
Muscles involved in plantar flexion
Gastrocnemius and soleus
212
Muscle involved in dorsi flexion
Tibialis anterior
