Muscular System Flashcards
(166 cards)
1
Q
process or the state of changing place or position of the body or a body part from one position to another
A
movement
2
Q
three types of movement
A
- amoeboid movement
- ciliary and flagellar movement
- muscular movement
3
Q
- involves the formation of pseurodpodia (false feet)
- result from localized contraction brought about by actin and myosin
- crawling motion
A
amoeboid movement
4
Q
organisms with amoeboid movement
A
- microorganisms and cells (amoeba)
- white blood cells
5
Q
- hairlike and has motile processes
- moves back and forth like oars, generating force in a direction perpendicular to its axis
A
cilia
6
Q
where are cilia found
A
- ciliate protist
- trachea
- reproductive system
7
Q
- whiplike; present singly or in small numbers
- moves with a whipping motion creating a force in the same direction as its axis
A
flagella
8
Q
organisms with flagella
A
- unicellular eukaryotes
- sperm cell
9
Q
- when muscles contract, they pull on skeletal elements, causing movement
- muscles work in pairs
A
muscular movement
10
Q
organisms with muscular movement
A
all animals, except sponges
11
Q
insects have strong, fast-beating flight muscles
A
invertebrate muscles (fibrillar muscle)
12
Q
- supply force for movement
- restrain motion
- act on the viscera to affect their actiity
- heat production
A
vertebrate muscles
13
Q
mechanism of muscular contraction
A
sliding filament theory
14
Q
explains how muscle fibers contract
A
sliding filament theory
15
Q
proposed the sliding filament theory
A
- Andrew Huxley
- Rolf Niedergerke
1954
16
Q
two types of filaments
A
- actin
- myosin
17
Q
actin
A
thin filaments
18
Q
myosin
A
thick filaments
19
Q
- organized contractile units
- basic unit of muscle contraction, spanning from one Z-line to another
A
sarcomere
20
Q
regions in the sarcomere
A
- A-band
- I-band
- H-zone
21
Q
where actin and myosin overlap
A
A-band
22
Q
actin only
A
I-band
23
Q
myosin only
A
H-zone
24
Q
regulatory proteins in action potential
A
- tropomyosin
- troponin
25
blocks muscle contraction
tropomyosin
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promotes muscle contraction
troponin
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what happens during action potential in muscles
1. influx of Ca2+
2. binds with troponin molecules
3. causes change to actin that exposes myosin binding sites
28
Steps in Sliding Filament Theory
1. detachment
2. hydrolysis
3. cross bridge
4. power stroke
5. repeat
29
- ATP binds to myosin head
- myosin detached from actin
detachment
30
what happens in detachment
- ATP binds to myosin head
- myosin detached from actin
31
- ATP splits into ADP+Pi
- causes myosin head to change to the ready position
hydrolysis
32
what happens during hydrolysis
- ATP splits into ADP+Pi
- causes myosin head to change to the ready position
33
myosin binds to actin
cross-bridge formation
34
what happens during cross-bridge formation
myosin binds to actin
35
- lose ADP+Pi
- myosin head performs power stroke
power stroke
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what happens during power stroke
- lose ADP+Pi
- myosin head performs power stroke
37
cycle continues as long as calcium ions are present and ATP is available, resulting in the shortening of sarcomeres and muscle contraction
repeat
38
Factors where the force generated during muscular contraction depends on
1. no. of cross-bridges formed
2. frequency of stimulation (rate coding)
3. initial length of muscle fibers (length-tension relationship)
39
muscles contract faster when ligher loads are applied and slower under heavier loads due to increased resistance against contraction
shortening velocity
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shortening velocity in ligher loads
faster
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shortening velocity in heavier loads
slower
42
Functions of the Muscular System
1. movement of the body
2. maintainance of posture
3. respiration
4. production of body heat
5. constriction of organs and vessels
6. contraction of the heart
43
contraction of muscle is responsible for overall movement
movement of the body
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keep you sitting and standing upright
postural muscles
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keep you breathing
respiratory muscles
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continuously pumps
heart muscles
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muscles constantly maintain tone
maintainance of posture
48
muscles of the thorax carry out breathing movements
respiration
49
when muscles contract, heat is given off as by-product
production of body heat
50
General Properties of Muscle Tissue
1. contractability
2. excitability/irritability
3. extensibility
4. elasticity
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- ability of the muscle to shorten forcefully/contract
- causes the strutures to which they are attached to move
- some forces oppose contraction that cause muscle to lengthen
contractability
52
contraction = ?
resting phase + shortening of muscles
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capacity of muscles to respond to a stimulus
excitability/irritability
54
stimulus to contract is from nerves that we consciously control
skeletal muscle
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- muscle fibers contract spontaneously
- also receive involuntary neural signals and hormonal signals to modulate force/rate of contraction
smooth and cardiac muscle
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- muscle can be stretched beyond its normal resting length and still be able to contract
extensibility
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- ability of muscle to recoil to its original resing length after it has been stretched
- recoil of muscle to go back to resting phase
elasticity
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muscle fibers that are capable of contracting when stimulated by nerve impulses
muscle tissue
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Two General Types of Muscles
1. striated
2. non-striated
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What are the different muscle tissues
1. skeletal
2. cardiac
3. smooth
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- fibers: striated, tubular and multi nucleated
- voluntary
- usually attached to skeleton
skeletal muscle
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skeletal muscle fiber
- striated
- tubular
- multi nucleated
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- fibers: non-striated, spindle-shaped, and uninucleated
- involuntary
- usually covering wall of internal organs
smooth muscle
64
smooth muscle fiber
- non-striated
- spindle-shaped
- uninucleated
65
- fibers: striated, branched and uninucleated
- involuntary
- only covering walls of the heart
cardiac muscle
66
cardiac muscle fiber
- striated
- irregular branched
- uninucleated
67
what is the striation due to
organization of actin and myosin filaments
68
Parts of skeletal muscle tissue
1. fascicles
2. perimysium
3. endomysium
4. epimysium
5. myofibrils
6. sarcolemma
7. sarcoplasm
69
group of muscle fibers is "bundled" as a unit within the whole muscle
fascicles
70
surrounds the fascicles
perimysium
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encases each muscle fiber inside each fascicle
endomysium
72
the outer layer of dense, irregular connective tissue around the whole muscle
epimysium
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repeating untis of sarcomeres
myofibrils
74
plasma membrane surrounding skeletal muscle fibers
sarcolemma
75
- cytoplasm of striated muscle cells
- contains myofibrils
sarcoplasm
76
functions of skeletal muscle tissue
1. chewing and swallowing
2. expanding and contracting your chest cavity
3. maintaining body posture
4. moving the bones in different parts of your body
5. protecting joints and holding them in place
77
synaptic connection between the terminal end of a motor neuron and a muscle
neuromuscular junctions
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Parts of the neuromuscular junctions
1. motor neuron
2. axon terminal
3. sarcolemma
4. acetylcholine (ACh)
5. synaptic cleft
79
stimulate muscles to contract
motor neuron
80
presynaptic membrane
axon terminal
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postsynaptic membrane
sarcolemma
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neurotransmitter
acetylcholine
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space betweent the presynaptic terminal and muscle fiber membrane
synaptic cleft
84
condition wherein the receptors are blocked by antibodies, reducing muscle contraction
Myasthenia gravis
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Types of Skeletal Muscle Fibers
1. slow oxidative fibers
2. fast oxidative fiber
3. fast glycolytic fiber
86
- red muscles
- for slow, sustained contractions without fatigue
- contain extensive blood supply
- abundant stored myoglobin
- important in maintaining posture in terrestrial vertebrates
slow oxidative fibers (red muscles)
87
slow oxidative fibers are abundant in what
stored myoglobin
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importance of slow oxidative fibers (red muscles)
maintaining posture in terrestrial vertebrates
89
- extensive blood supply
- high density of mitochondria and myoglobin
- function aerobically
- for rapid, sustained activities
fast oxidative fiber
90
fast oxidative fiber have high density of what?
- mitochondria
- myoglobin
91
function of fast oxidative fiber
aerobically, rapid sustained activities
92
involves continuous movement fueled by oxygen from the air you breathe
Aerobic exercise
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- lacks efficient blood supply
- pale in color
- function anaerobically
- fatigue rapidly
fast glycolytic fiber (white muscles)
94
function of fast glycolytic fiber (white muscles)
anaerobically
95
results from a single action potential in a motor neuron
muscle twitch
96
muscle twitch diagram
1. latent period
2. contraction period
3. relaxation period
97
- gradual increase in muscular contraction due to rapidly repeated stimulation
- occurs when the muscle is stimulated a second time immediately after the relaxation phase has ended
treppe
98
results mainly from the inability of the contractile and metabolic processes of muscle fiber to continue supplying the same work output
fatigue
99
- specialized, organized type of tissue that only exists in the wall of heart
- under the control of the autonomic nervous system
- consists of cells called cardiomyocytes
- syncytium
cardiac muscle tissue
100
controls the cardiac and smooth muscle tissue
autonomic nervous system
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cells in the cardiac muscle tissue
cardiomyocytes
102
all muscle cells are connected and behave as a single unit
syncytium
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- specialized junctions between cardiac muscle fibers (cardiomyocytes) that allow for rapid electric transmission, called an action potential, and nutrient exchange
- are important because they allow for the cells in our hearts to beat as one
Intercalated discs
104
creates the striation in cardiomyocytes
- myofibrils
- sarcomere
105
muscle of the heart
myocardium
106
helps spread action potential from the surface to deep inside the cells making the excitation-coupling contraction faster
T-tubules
107
what do specialized junction in the cardiac muscle fibers allow
- rapid electrical transmission (action potential)
- nutrient exchange
108
Three components of the intercalated disc
1. Fascia adherens
2. Desmosomes
3. Gap junctions
109
- considered as anchoring junctions
- anchor cells firmly by lingking the cell membrane to the actin cytoskeleton
- protects the heart tissue and allows the heart to beat as one unit
Fascia adherens
110
fascia adheres are considered as what?
anchoring junctions
111
how does fascia adherens anchor cells
linking the cell membrane to the actin cytoskeleton
112
what does the fascia ahderens protect and allow
- protect heart tissue
- allow heart to beat as one unit
113
- also called Macula adherens
- prevent separation during contraction by binding intermediate filaments, anchoring the cell membrane to the intermediate filament network, joining the cells together
Desmosomes
114
other term for desmosomes
Macula adherens
115
how do desmosomes prevent separation during contraction
by binding intermediate filaments
116
how do desmosomes bind intermediate filament
anchoring cell membrane to the intermediate filament network
117
- considered as communicating junctions
- allow impulses to spread from one cardiac muscle cell to another, allowing sodium, potassium, and calcium ions to flow between adjacent cells, propagating the action potential, and ensuring coordinated contractions
Gap junctions
118
Gap junctions are considered as what?
communicating junctions
119
function of gap junctions
1. allow impulses to spread, allowing sodium, potassium, and calcium ions to flow between adjacent cells
2. propagate action potential
3. ensure coordinated contractions
120
involved in force transmission between cardiac muscle cells
Fascia adherens
121
responsible fo mechanical stability and preventing cell separation
Desmosomes
122
enable electrical coupling for synchronized contraction
Gap junctions
123
Two Types of Cardiac Muscle Cells
1. conducting cells
2. contractile cells
124
- responsible for generating and transmitting electrical impulses that initiate and coordinate heart contractions
- found in specialized areas of the heart, such as the sinoatrial (SA) node, the atrioventricular (AV) node
- make up a small percentage of cardiac muscle cells
conducting cells
125
conducting cells are responsibe for what?
generating and transmitting electrical impulses
126
where are conducting cells found
- sinoatrial (SA) node
- atrioventricular (AV) node
127
- make up the majority of cardiac muscle cells
- responsible for the actual contraction of the heart muscle
contractile cells
128
contractile cells are responsible for what?
actual contraction of heart muscle
129
Two types of Syncytium
1. Atrial syncytium
2. Ventricular syncytium
130
makes the wall of atria
atrial syncytium
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makes the wall of ventricles
ventricular syncytium
132
- separates the two syncytium in the heart
- non-conductve to electrical impulse
atrioventricular ring
133
- point where the impulse are passed from the atria to the ventricle
- takes impulase from the SA node to ventricle after a delay to initiate ventricular contraction after the atria emptied their blood to the ventricle
A-V bundle
133
how do cardiac muscle fibers contract
via excitation-contractoin coupling
134
mechanism unique to cardiac muscle
calcium-induced calcium release
135
describes the process of converting an electrical stimulus (action potential) into a mechanical response (muscle contraction)
excitation-contraction coupling
136
process whereby calcium can trigger release of further calcium from the muscle sarcoplasmic reticulum
calcium-induced calcium release
137
where are calcium further released from
muscle sarcoplasmic reticulum
138
Pathway of Cardiac Muscle Contraction
1. Action potential is conducted to contractile cardiomyocytes through gap junctions
2. As action potential travels between sarcomeres, it activates calcium channels in T-tubules, resulting in influx of calcium ions into the cardiomyocyte
3. Calcium in cytoplasm binds to troponin-C which moves the troponin complex away from actin freeing the actin and allowing to be bound by myosin and initiates contraction
139
where does the calcium in cytoplasm bind to
cardiac troponin-C
140
- found throughout the body
- under the control of the autonomic nervous system
- contract more slowly than skeletal muscle when stimulated by neurotransmitter from nervous system
smooth muscle tissue
141
location of smooth muscles
1. Skin
2. Tracks found in reproductive, respiratory, and urinary systems
3. Organs that are hollow
4. Vessels
5. Eyes
142
smooth muscle nuclei
one, central portion
142
skeletal muscle nuclei
multiple, around peripheral
143
cardiac muscle nuclei
one or two, central portion
144
Smooth muscle layers of intestine
1. longitudinal layer
2. circular layer
3. oblique layer
145
runds along the whole length in a long way of the organ as the outermost smooth muscle layer, helping it become shorter during contraction
longitudinal layer
146
- runs in a perpendicular direction and forms around the organ circumference in a circular direction
- narrow or constrict the organ during contraction
circular layer
147
helps to further break down food before it reaches the intestine
oblique layer
148
why does smooth muscle not contain striations
abscence of sarcomeres and myofibrils
149
attach to the sarcolemma, which is the smooth muscle cells outer sheath, and they work much like the z discs in the sarcomere
dense bodies
150
dense bodies also allow for the attachment of what intermediate filaments
- desmin
- vimentin
151
Subtypes of Smooth Muscle Tissue
1. single-unit smooth muscle
2. multi-unit smooth muscle
152
- also called as unitary smooth muscle, innervated by one or very few nerve fibers per bundle
- can contract an entire sheet of smooth muscle in unison due to the presence of gap junctions, which allow the electrical signal to spread rapidly to all of the adjoining smooth muscle cells
- primarily found in the hollow organ such as the intestines
single-unit smooth muscle
153
gap junctions in single-unit smooth muscle
many, allowing electrical signal to spread rapidly
154
- contain fewer gap junctions, electrical impulses spread less efficiently between individual cells
- multiple nerve fibers found here to deliver that impulse
- found more in the skin, eyes, blood vessels
multi-unit smooth muscle
155
Skeletal Muscle Disorders
1. arthritis
2. tetanus
156
refers to inflammation of the joints that can cause pain and stiffness, affecting mobility
arthritis
157
serious bacterial infection caused by _Clostridium_ _tetani_ that affects the nervous system and leads to painful muscle stiffness and spasms
tetanus
158
causes tetanus
_Clostridium_ _tetani_
159
Cardiac muscle disorders
1. myocardial infarction (heart attack)
2. stress cardiomyopathy (broken heart syndrome)
160
occurs when blood flow to a part of the heart is blocked, causing damage to heart muscle tissue
myocardial infarction (heart attack)
161
temporary heart condition often triggered by extreme emotional or physical stress that mimics a heart attack
stress cardiomyopathy
162
Smooth Muscle Disorders
1. irritable bowel syndrome (IBS)
2. gastroesophageal reflux disease (GERD)
163
gastrointestinal disorder characterized by chronic abdominal pain and changes in bowel habits, including diarrhea and constipation
irritable bowel syndrome (IBS)
164
chronic digestive condition where stomach acid flows back into the esophagus, causing irritation
gastroesophageal reflux disease (GERD)
