Muscular System Flashcards
1
Q
Three basic muscle types
A
Skeletal
Cardiac
Smooth
2
Q
What is different about muscle cells?
A
They’re elongated
3
Q
Muscle cells are known as
A
Muscle fibers
4
Q
Contraction of muscles is due to the movement of
A
Microfilaments
5
Q
Prefix myo refers to
A
Muscle
6
Q
Prefix mys refers to
A
Muscle
7
Q
Prefix sarco refers to
A
Flesh
8
Q
Skeletal muscles are attached to bones by?
A
Tendons
9
Q
How many nucleus do skeletal muscle cells have?
A
They are multinucleate
10
Q
Are skeletal muscles straited?
A
Yes
11
Q
What does it mean to be straited?
A
To have visible banding
12
Q
Are skeletal muscles voluntary?
A
Yes
13
Q
What does it mean when a muscle is voluntary?
A
It is subject to conscious control
14
Q
What are skeletal muscle cells surrounded and bundled by?
A
Connective tissue
15
Q
What is the connective tissue which wraps around a single skeletal muscle fiber?
A
Endomysium
16
Q
What is the connective tissue which wraps are a fascicle (bundle) of skeletal muscle fibers?
A
Perimysium
17
Q
What is the connective tissue which covers the entire skeletal muscle?
A
Epimysium
18
Q
The connective tissue on the outside of the epimysium
A
Fascia
19
Q
What connective tissue wrapping blends into a connective tissue attachment
A
Epimysium
20
Q
Cord-like structure
Connective tissue attachment
A
Tendon
21
Q
Sheet-like structure
Connective tissue attachment
A
Aponeuroses
22
Q
Sites of muscle attachments
A
Bones
Cartilages
Connective tissue coverings
23
Q
How much striation to smooth muscles exhibit?
A
None
24
Q
What is the cell shape of smooth muscles?
A
Spindle-shaped
25
How many nucleus do cells of smooth muscle contain?
One
26
Are smooth muscles voluntary or involuntary?
Involuntary
27
A muscle with no conscious control is
Involuntary
28
Where are smooth muscles mainly found?
The walls of hollow organs
29
Do cardiac muscles have striations?
Yes
30
How many nucleus do cardiac muscles have?
Usually one
31
Where are cardiac muscle cells joined?
Intercalated disc
32
Cardiac muscles are involuntary or voluntary?
Involuntary
33
Where are cardiac muscles found?
The heart only
34
Functions of muscles
Produce movement
Maintain posture
Stabilize joints
Generate heat
35
Where are nuclei located in skeletal muscle cells?
Sacrolemma
36
Specialized plasma membrane
Sacrolemma
37
Specialized smooth endoplasmic reticulum
Sacroplasmic reticulum
38
Bundles of myofilaments
Myofibrils
39
What is aligned to give muscles distinct bands?
Myofibrils
40
The light band of striated muscle is the
I band
41
The dark band of striated muscles is the
A band
42
Contractile unit of a muscle fiber
Sarcomere
43
Thick filaments =
Myosin filaments
44
What are myosin filaments composed of?
The protein myosin
45
What do myosin fibrils contain?
ATPase enzymes
46
Thin filaments =
Actin filaments
47
What are actin filaments composed of?
The protein actin
48
Which filaments have heads?
Myosin
49
Examples of myosin filament heads
Extensions
| Cross bridges
50
Do myosin and actin overlap?
Somewhat
51
What types of body movements are muscles responsible for?
All of them
52
At rest, what does the bare zone lack?
Actin filaments
53
What does the sacroplasmic reticulum (SR) store?
Calcium
54
Ability to receive and respond to stimulus
Irritability
55
Ability to shorten when an adequate stimulus is received
Contractility
56
What needs to stimulate skeletal muscles in order for them to contract?
Nerves
57
A motor unit is composed of
One neuron
| The muscle cells stimulated by that neuron
58
Association sure of nerve and muscle
Neuromuscular junctions
59
Gap between nerve and muscle
Synaptic cleft
60
How much contact is there in a synaptic cleft?
None
61
In a synaptic cleft, what is the area between the nerve and muscle filled with?
Interstitial fluid
62
Chemical released by nerve upon arrival of nerve impulse
Neurotransmitter
63
The neurotransmitter for skeletal muscle is
Acetylcholine
64
Neurotransmitter attaches to receptors of the
Sacrolemma
65
During transmission of nerve impulses the sacrolemma becomes permeable to
Sodium
66
What does sodium rushing into a cell generate?
Actin potential
67
Can muscle contraction be stopped after being started?
No
68
In the sliding filament theory of muscle contraction activation by nerve causes ____ to attach to binding site on the ____
Myosin heads
| Thin filaments
69
In the sliding filament theory of muscle contraction, a continuation of action causes what of myosin along the actin?
Sliding
70
What is the result of the sliding filament theory?
The muscle is shortened/contracted
71
Muscle fiber contraction is
"All or none"
72
Not all skeletal muscle fibers may be ____ durning the same ____
Stimulated
| Interval
73
What muscle fiber contractions five different responses?
Different combinations
74
Different degrees of skeletal muscle shortening
Graded responses
75
Single, brief contraction
| Not a normal muscle function
Twitch
76
One contraction is immediately followed by another
Tetanus
77
The muscle does not completely return to a resting state
Tetanus
78
Summing of contractions
Tetanus
79
Incomplete tetanus
Unfused
80
Some relaxations occurs between contractions
Unfused
81
Results are summed
Unfused
82
Complete tetanus
Fused
83
No evidence of relaxation before the following contractions
Fused
84
The result is a sustained muscle contraction
Fused
85
Muscle force depends on
Number of fibers stimulated
86
More fibers contracting results in
Greater muscle tension
87
Muscles can continue to contract unless
They run out of energy
88
What do muscles initially use for energy?
Stored ATP
89
How is energy from ATP released?
Bonds are broken
90
How much ATP is stored by muscles?
About 4-6 seconds worth
91
After the initial use of ATP, what must be utilized to produce ATP?
Other pathways
92
Energy for muscle contraction comes from what?
Direct phosphorylation
93
Muscle cells contain
Creatine phosphate
Aerobic respiration
Anaerobic glycolysis
94
High-energy molecule
CP
95
After ATP is depleted, what is left?
ADP
96
CP transfers energy to
ADP
97
Why does CP transfer energy to ADP?
To regenerate ATP
98
Series of metabolic pathways that occur in the
Mitochondria
99
What is broken down to CO2 and H2O, to release energy?
Glucose
100
Anaerobic glycolysis reactions breakdown glucose without
Oxygen
101
During anaerobic glycolysis, glucose is broken down to ____ to produce some ____
Pyruvic acid
| ATP
102
Which energy reaction is efficient but not fast?
Anaerobic glycolysis
103
In anaerobic glycolysis, huge amounts of what are needed?
Glucose
104
Lactic acid produces
Muscle fatigue
105
When a muscle is fatigued, it is unable to
Contract
106
What is the most common reason for muscle fatigue?
Oxygen debt
107
How can oxygen debt be removed?
Oxygen must be "repaid"
108
Oxygen is required to get rid of
Lactic acid
109
Increasing acidity and lack of ATP causes muscles to contract
Less
