Muscles Flashcards
(117 cards)
1
Q
Myo
A
Muscle
2
Q
Myology
A
The study of muscles
3
Q
The human body has ______ skeletal muscles
A
600+
4
Q
How many skeletal muscles are in the face and neck
A
162
5
Q
4 functions of the muscular system
A
Movement
Posture
Joint stability
Heat production
6
Q
Type of muscle tissue that is attached to bone and skin
A
Skeletal
7
Q
Type of muscle tissue that appears striated
A
Skeletal muscle
8
Q
Type of muscle tissue that is very powerful
A
Skeletal muscle
9
Q
Type of muscle tissue that is voluntary
A
Skeletal muscle
10
Q
Type of muscle tissue that is multinucleated
A
Skeletal muscle
11
Q
Type of muscle tissue that is found in the heart
A
Cardiac muscle
12
Q
Type of muscle tissue that appears striated and branched
A
Cardiac muscle tissue
13
Q
Type of muscle tissues that are involuntary
A
Cardiac and smooth
14
Q
Type of muscle tissues that have a single nuclei
A
Cardiac and smooth
15
Q
Type of muscle tissue that is found in the wall of hollow organs
A
Smooth muscle
16
Q
Type of muscle tissue that appears stratified squamous, NO striations
A
Smooth
17
Q
5 rules of skeletal muscles
A
- All muscles cross at least one point
- Most of the muscle lies proximal to the joint crossed
- All muscles have two attachments: origin and insertion
- Muscles only pull NEVER push
- During contraction the insertion moves towards origin
18
Q
Less movable attachment site or muscle attachment to stationary bone
A
Origin
19
Q
More movable attachment site or muscle attachment to moveable bone
A
Insertion
20
Q
Primary mover responsible for causing a movement (joint action)
A
Agonist
21
Q
Muscle that opposes movement of the agonist; provides precision and control
A
Antagonist
22
Q
Muscles that assist the agonist by producing the same movement at the same time. Makes a more effective movement
A
Synergist
23
Q
Example of an agonist
A
Biceps brachii is the main flexor of the elbow joint
24
Q
Example of an antagonist is
A
Triceps brachii performs the opposite function of the biceps brachii in the elbow joint
25
Example of a synergist
Brachialis assists the biceps brachii in flexion of the elbow
26
Thick filaments of a muscle fiber
Myosin
27
Type of muscle that connects to bones, voluntary
Skeletal
28
Stores neurotransmitters
Vesilles
29
Neurotransmitter used to cause muscle contraction
Acetylcholine
30
Connects muscle to bone
Tendon
31
Organelle that provides the energy needed for muscle contractions
Mitochondria
32
Connects bones to other bones
Ligament
33
Surrounds fascicles
Perimysium
34
Thin filaments of a muscle fiber
Actin
35
Minimal level of stimulus to cause a contraction
Threshold
36
Section of myofibril from one Z line to the next Z line
Sarcomere
37
Bundle of muscle fibers
Fascille
38
Theory that explains how muscle contraction works; sliding _____ theory
Filament
39
Outermost layer, surrounds entire muscle
Epimysium
40
Describes muscles that are striped in appearance
Striated
41
Muscle fiber membrane
Sarcolemma
42
Space between a neuron and the muscle, synaptic ____
Cleft
43
Overlapping patterns of actin and myosin; I and A _______
Bands
44
Membranous channels that surround the myofibrils; sarcoplasmic _________
Reticulum
45
When muscles become tired
Fatigue
46
Type of muscle found in the digestive tract, involuntary
Smooth
47
Type of muscle that makes up the heart
Cardiac
48
The space where the nerve and muscle meet
Neuromuscular junction
49
Carries messages towards myofibril
Axon
50
Stores acetylcholine
Synaptic vesticles
51
Gap between axon and muscle fiber
Synaptic cleft
52
Specialized area of sarcolemma that receives messages
Motor end plate
53
Chemical that causes a contraction
Acetylcholine
54
What is the name of the stimulus that travels down the axon to the muscle fiber?
An action potential
55
Does the terminal end of the axon enter the muscle fiber
No there is a gap between the two
56
Does acetylcholine enter the muscle fiber
No
57
What chemical enters the muscle fiber, resulting in an action potential through the muscle fiber
Sodium
58
____ is bound to myosin side arm
ATP
59
ATP _______ into ADP + P (high energy)
Cleaves
60
What are the steps for muscle movement?
```
Action potential
Myosin-actin binding
Power stroke
ATP Binding actin-myosin released
ATP Cleavage
```
61
What happens in step one (action potential)
A nerve action potential releases acetylcholine into the synaptic cleft opening the Na+ channels
Action potential spreads across sarcolemma releasing Ca into sarcoplasma
62
What happens in step two (myosin actin binding)
1. Ca binds to troponin
2. A shape change in troponin moves tropomyocin out of the way of actin binding site
3. Actin and myosin bind using energy from cleaved ATP
63
What happens in step 3 (power stroke)
1. Side arm pivots so myosin and actin slide by each other shortening the sarcomere
2. ADP and P released low energy
64
What happens in step 4 (actin-myosin release)
1. A different ATP molecule binds to active site
| 2. Actin released
65
Step 5 (ATP cleavage)
1. Return to high energy state
| 2. Cycle will repeat if Ca still available
66
If a muscle is contracted what happens if a new molecule of ATP is not available
Muscle stays contracted -cramps
67
Why does rigor mortis occur
ATP is not available to control Ca release so contractions are continuous 6-8 hours after death. Body relaxes 16-24 hours as enzymes break down contractive structures
68
What happens to the length of the sarcomere during a contraction
The sarcomere shortens
69
What chemical exposes the binding site for actin and myosin
Calcium
70
What is the source of energy for a contraction?
ATP
71
What is the name of the step in which the actin filament is actively contracted
Powerstroke
72
During muscle contraction the muscle becomes ________
Tense
73
During muscle contraction the muscle ______ in length
Shortens
74
During muscle contraction the diameter of the muscle _______
Expands
75
A muscle that provides the major force for producing a specific movement is called
An agonist
76
A muscle group that works with and assists the action of a prime mover is a
Synergist
77
In flexing the forearm at the elbow, the triceps brachii acts as
An antagonist
78
In skeletal muscle contraction, calcium apparently acts to
Remove the blocking action of tropomyosin
79
Calcium ions bind to the ________ molecule in skeletal muscles
Troponin
80
An elaborate network of membranes and skeletal muscle cells that functions in calcium storage is the
Sarcoplasmic reticulum
81
A sarcomere is
The area between two Z discs
82
The major function of the sarcoplasmic reticulum in muscle contraction is to
Regular intracellular calcium concentration
83
The sliding filament model of contraction involves
Actin and myosin sliding past each other and partially overlap
84
During vigorous exercise there maybe insufficient oxygen available to completely break down pyruvic acid for energy. As a result, the pyruvic acid is converted to
Lactic acid
85
The role of calcium ions in muscle contraction is to
Bind to regulatory sites on troponin, changing the configuration
86
One functional unit of a skeletal muscle is
A sarcomere
87
The contractile units of skeletal muscles are
Myofibrils
88
Rigor mortis occurs because
No ATP is available to release attached actin and myosin molecules
89
During muscle contraction, myosin cross bridges attach to which active sites?
Actin filaments
90
Which of the following are composed of myosin?
Thick filaments
91
The striations of skeletal muscle cells are produced, for the most part, by
The arrangement of myofilaments
92
Muscle that opposes and reverses the action of another muscle
Antagonist
93
Muscle that aids another by promoting the same movement
Synergist
94
Muscle that is primarily responsible for bringing about a particular movement
Agonist
95
Which type of muscle generally remains in a state of partial contraction when you're keeping your legs straight
Skeletal muscle
96
Where is cardiac muscle tissue located in the body?
Heart
97
Moves your eyeball
Skeletal muscle
98
A ___________ is a single skeletal muscle cell
Muscle fiber
99
Muscle fibers are made up of fiber bundles of that contain hundreds of ________
Myofibrils
100
Composed of a T-tubule, the terminal cisternae, and gaps
Longitudinal tubules
101
Cylindrical structures that carry out contraction
Myofibril
102
Extensions of the sarcolemma that separate the sarcomeres
Transverse tubules
103
Specialized plasma membrane of the skeletal muscle cell; forms membrane connections between each of the sarcomeres
Sarcolemma
104
The specialized endoplasmic reticulum of the muscle cell
Sarcoplasmic reticulum
105
Units of the myofibrils
Mitochondria
106
The bands that mark the sarcomere's borders
Z line
107
The bands that mark the middle of the sarcomere
M line/ M disc
108
Under a micrograph they are the lightest and least dense structures; composed of actin, troponin, tropomyosin
Thin filaments
109
Much more dense than think filaments; composed of myosin
Thick filaments
110
The distance between the ends of the thin filaments known as
H zone
111
The distance between the thick filaments of one sarcomere and the thick filaments of an adjacent sarcomere was known as the
I Band
112
The length of the thick filaments was known as the
A band
113
The _______ and ______ shortens, but the ______ does not shorten during muscle contraction
I band
H zone
A band
114
Chemically, muscle contraction is driven by ___________ and triggered by the release of ______ from the sarcoplasmic reticulum
ATP hydrolysis
Ca2+
115
Ca2+ binds to __________ in the thin filaments, exposing the myosin binding sites on actin
Troponin
116
The movement where the myosin head pulls the thin filaments inward is called the
Power structure
117
What is the order of chemicals in a muscle contraction
1. Electrochemical signal causes release of Ca2+ from sarcoplasmic reticulum
2. Ca2+ binds troponin causing a conformational change of the thin filament
3. Myosin heads bind to actin
4. Power stroke (ADP and P dissociate from myosin)
5. ATP binds myosin head
6. Thin filament returns to relaxed state
