Muscular System Flashcards
1
Q
Three types of muscle
A
Skeletal, smooth, and cardiac
2
Q
Large, cigar-shaped, and multinucleated cells that cover our bone and cartilage framework
A
Skeletal
3
Q
Skeletal, striated, and voluntary
A
Skeletal
4
Q
Visceral, non striated, and involuntary
A
Smooth
5
Q
Spindle shaped and uni nucleate
A
Smooth
6
Q
Surrounded by scant endomysium
A
Smooth
7
Q
Arranged in layers where one runs circularly and the other longitudinally.
A
Smooth
8
Q
As the two layers of smooth muscles contract and relax, they change in ___ and ___ of the organ.
A
size, shape
9
Q
How do you describe smooth muscle contraction?
A
Slow and sustained
10
Q
Cardiac, striated, and involuntary
A
Cardiac
11
Q
Arranged in spiral or figure eight shaped bundles
A
Cardiac
12
Q
What do you call a special gap junction?
A
Intercalated discs
13
Q
How do cardiac muscle contract at a steady rate?
A
It was set by a heart’s in-house pacemaker
14
Q
Six muscle functions
A
Produce movement
Maintain posture and stabilized joints
Support and protection
Generate heat
Circulation and fluid movement
Communication
15
Q
Long cylindrical multinucleated cells
A
Muscle fiber
16
Q
Plasma membrane of muscle fiber
A
Sarcolemma
17
Q
Cytoplasm that contains organelles glycogen and myoglobin
A
Sarcoplasm
18
Q
For energy
A
Glycogen
19
Q
For oxygen storage
A
Myoglobin
20
Q
Cylindrical organelles that runs the length of the muscle fiber and responsible for contraction
A
Myofibrils
21
Q
Structural and functional unit of a myofibril
A
Sarcomere
22
Q
Thin filaments or protein filaments that are anchored to the z line which is involved in contraction
A
Actin
23
Q
Thick filaments or protein filaments with head that bind to actin and pull during contraction
A
Myosin
24
Q
Defines the boundaries of a sarcomere and anchors actin
A
Z line
25
Center of the sarcomere which anchors myosin
M line
26
Light region containing only actin filaments
I band
27
Dark region containing the full length of myosin filaments
A band
28
The central part of the a band with only myosin that disappears during contraction
H zone
29
Projections at the end of thick filaments
Myosin heads
30
Attachment of a myosin head to an active site of actin in the thin filaments
Cross bridges
31
Elastic filaments that run through the core of the thick filament
Titin
32
Specialized smooth endoplasmic reticulum that surrounds myofibrils
Sarcoplasmic reticulum
33
Stores and releases calcium ions which are crucial for muscle contraction
Sarcoplasmic reticulum
34
Four special functional properties of muscle fibers
Irritability
Contractility
Extensibility
Elasticity
35
The ability to receive and respond to a stimulus
Irritability
36
The ability to forcibly shorten when adequately stimulated
Contractility
37
Ability of muscle fibers to stretch
Extensibility
38
Ability to recoil and resume their resting length after being stretched
Elasticity
39
A signal sent by a motor neuron to stimulate a muscle fiber
Nerve stimulus
40
Carries an electrical signal from the brain or spinal cord to the muscle
Motor neuron
41
The point where the motor neuron meets the muscle fiber. This is where the nerve signal is transmitted to the muscle.
Neuromuscular junction
42
When the nerve signals reaches the end of the neuron it triggers the release of a chemical messenger
Release of neurotransmitter
43
Chemical messenger
Acetylcholine
44
The space between the neuron and the muscle fiber
Synaptic cleft
45
An electrical impulse generated in the muscle fiber in response to the nerve stimulus
Action potential
46
Ach binds to receptors on a muscle fibers plasma membrane which triggers ion channels to open
Binding of acetylcholine
47
Sodium ions rush into the muscle fiber which causes the inside to become less negative
Sodium influx
48
Less negative
Depolarization
49
Change in electrical charge that travels along the sarcolema and into the muscle fiber
Propagation
50
The action potential triggers the sarcoplasmic reticulum to release calcium ions into the muscle fiber
Calcium release
51
Calcium initiates the interaction between actin and myosin
Contraction
52
When does the sliding begins?
When the nervous system activates muscle fibers and the myosin heads attached to binding sites on the thin filaments.
53
The formation of cross bridges requires?
Calcium ions and atp
54
A single nerve impulse that stimulates the muscle which leads to quick contraction and complete relaxation
Single twitch
55
Basic response of a muscle fiber when stimulated once
Single twitch
56
Second nerve stimulus arrives before the muscle has fully relaxed from the first contraction and the second contraction is stronger than the first.
Wave summation
57
The muscle does not fully relax between contractions with faster stimulation. The contractions begin to add together which creates a smoother and more forceful response instead.
Incomplete or unfused tetanus
58
There is still some visible relaxation between contradictions which gives a slightly wavering tension
Incomplete or unfused tetanus
59
If stimulation continues for a long time then the muscle eventually runs out of energy or accumulates waste products like lactic acid that impaired ability to contract.
Fatigue
60
The muscle becomes weaker and may eventually stop contracting altogether even if the nerve signals continue
Fatigue
61
When the stimulation frequency becomes so high that there is no relaxation at all then the muscle reaches a state of complete tetanus.
Complete or fused tetanus
62
It produces the strongest and smoothest contraction possible for the muscle
Complete or fused tetanus
63
Consists of a single motor neuron and all the muscle fibers it innervates.
Motor unit
64
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Small motor units control fine movements while large motor units generate more force.
The more motor units that are activated then the stronger the muscle contraction is.
65
The muscle contraction strength increases as the intensity of the stimulus increases
Graded muscle response
66
The weakest stimulus that can cause a contraction
Threshold stimulus
67
A moderate stimulus recruits more motor units which increase contraction strength
Submaximal stimulus
68
The strongest stimulus activates all available motor units in the muscle
Maximal stimulus
69
The muscle cannot contract beyond its maximum capacity
Supramaximal stimulus
70
Methods of generating atp and their duration
Direct phosphorylation - 10-15 seconds
Anaerobic pathway - 30-60 seconds
Aerobic pathway - hours
71
Anaerobic pathway mechanism
Anaerobic glycolysis and lactic acid formation
When oxygen supplies and sufficient glucose is broken down into pyruvate via glycolysis
72
Aerobic pathway mechanism
Aerobic cellular respiration and oxidative phosphorylation
During prolonged activity muscles rely on oxygen to break down glucose glycogen fatty acid and amino acids in the mitochondria
73
Unable to contract even though being stimulated still because of working without rest
Muscle fatigue
74
A person is not able to take in oxygen fast enough to keep the muscles supplied with all the oxygen they need
Oxygen deficit
75
Early occurs but it is when people literally collapse when their muscles become fatigue and could no longer work
True muscle fatigue
76
Two types of muscle contraction
Isometric and isokinetic
77
Muscle generates tension without changing length and no movement occurs
Isometric contraction
78
The muscle changes left at constant speed and the tension can vary. It requires specialized equipment to maintain constant velocity.
Isokinetic
79
Four interactions of skeletal muscles in the body
Prime mover
Antagonist
Synergists
Fixators
80
Muscle that has the major responsibility for causing a particular movement
Prime mover
81
Muscles that oppose or reverse a movement
Antagonists
82
Help prime movers
Synergists
83
Hold a bone still or stabilize the origin of a prime mover
Fixators
84
Seven factors to consider in naming skeletal muscles
Direction
Relative size
Location
Number of origin
Location of origin or insertion
Shape
Action
85
Covers the frontal bone which allows to raise your eyebrows and wrinkle your forehead
Frontalis
86
Covers the posterior of the skull and pulls the scalp posteriorly
Occipitalis
87
Run in circles around the eyes which allows to close squint blink and wink
Orbicularis oculi
88
Kissing muscle
Orbicularis oris
89
Flattens the cheek and the chewing muscle
Buccinator
90
Extends from the corner of the mouth to the cheekbone. The smiling muscle.
Zygomaticus
91
Closest the jaw by elevating the mandible.
Masseter
92
Synergist of the masseter and a fan shaped muscle overlying the temporal bone
Temporalis
93
Sad clown face muscle as it pulls the corners of the mouth inferiorly
Platysma
94
They flex the neck
Sternocleidomastoid
95
Covers the upper part of the chest and forms the anterior wall of the armpit. Acts to adduct and flex the arm.
Pectoralis major
96
Deep muscles found between the ribs
Intercostal muscles
