Musculoskeletal System Flashcards
1
Q
Slow, Oxidative Fibers (Type 1) mitochondria, capillaries, myoglobin content, and glycogen content
A
Mitochondria: Numerous
Capillaries: Numerous
Myoglobin content: High (red fibers)
Glycogen content: Low
2
Q
Fast, Oxidative-Glycolytic Fibers (Type 2a) mitochondria, capillaries, myoglobin content, and glycogen content
A
Mitochondria: Numerous
Capillaries: Numerous
Myoglobin content: High (red fibers)
Glycogen content: Intermediate
3
Q
Fast, Glycolytic Fibers (Type 2b) mitochondria, capillaries, myoglobin content, and glycogen content
A
Mitochondria: Sparse
Capillaries: Sparse
Myoglobin content: Low (white fibers)
Glycogen content: High
4
Q
Slow, Oxidative Fibers (Type 1) rate of fatigue, speed of contraction, and major locations
A
Rate of fatigue: Slow
Speed of contraction: Slow
Major location: Postural muscles of back
5
Q
Fast, Oxidative-Glycolytic Fibers (Type 2a) rate of fatigue, speed of contraction, and major locations
A
Rate of fatigue: Intermediate
Speed of contraction: Fast
Major location: Major muscles of legs
6
Q
Fast, Glycolytic Fibers (Type 2b) rate of fatigue, speed of contraction, and major locations
A
Rate of fatigue: Fast
Speed of contraction: Fast
Major location: Extraocular muscles
7
Q
Red fibers
A
Well vascularized and have lots of myoglobin, which stores oxygen. Myoglobin is an iron- and oxygen-storage protein found in cardiac and skeletal muscle.
Red fibers contract slowly and resist fatigue.
8
Q
White fibers
A
Low in myoglobin; they contract quickly, but tire easily.
9
Q
Three different motor units in the human body
A
Type 1, type 2a, type2b
10
Q
Type 1 motor unit
A
Highly fatigue resistant, has a lower activation threshold, contains fewer muscle fibers, and has low force generation during contraction.
11
Q
Type 2 motor unit
A
Resistant to fatigue, has a higher activation threshold, and the force produced is higher compared to type 1
12
Q
Type 2b motor unit
A
Fatigable, has a high activation threshold, innervates the most muscle fibers, and generates the greatest force during contraction
13
Q
The structural unit of a muscle is a _______
A
muscle fiber
14
Q
The functional unit of a muscle, consisting of a motor neuron and the muscle fibers it controls, is a _______
A
motor unit
15
Q
Fascia
A
A band or sheet of connective tissue, that attaches, encloses, and separates muscles and other internal organs. It interpenetrates and
surrounds the muscles, bones, nerves, and blood vessels of the body.
16
Q
How is fascia classified?
A
Fascia is classified by layer as superficial fascia, deep fascia, and visceral or
parietal fascia, or by its function and anatomical location.
17
Q
Deep fascia
A
Associated with, bone (periosteum and endosteum), cartilage (perichondrium), blood vessels (tunica externa), muscles (epimysium, perimysium, and endomysium), nerves (epineurium, perineurium, and endoneurium)
High density of elastin fiber for extensibility and resilience
18
Q
Fascia function
A
Often surrounds groups of muscles, forming compartments.
Fasciae also reduce friction between muscles and blood vessels and nerves.
19
Q
Muscle functions (broad sense)
A
Prime mover or agonist, fixators, synergist, antagonist
20
Q
Prime mover or agonist
A
The main muscle responsible for producing a specific movement of the body (e.g., concentric contraction).
21
Q
Fixators
A
Steady the proximal parts of a limb while movements are occurring in distal parts.
22
Q
Synergist
A
Complements the action of prime movers—for
example, by preventing movement of the intervening joint when a prime mover passes over more than one joint.
23
Q
Antagonist
A
A muscle that opposes the action of a prime mover. As a prime mover contracts, the antagonist progressively relaxes, producing a smooth movement.
24
Q
Functions (narrow sense)
A
Flexors and extensors, abductors and adductors
25
What muscles shorten the most during contraction?
When muscles contract, the fibers shorten to about 70% of their resting length. Muscles with a long parallel fascicle arrangement shorten the most, providing considerable range of movement at a joint, but are not powerful.
26
Muscle power
Muscle power increases as the total number of muscle cells increases. Therefore, the shorter, wide pennate muscles that “pack in” the most fiber bundles shorten less but are most powerful.
This statement is not quite correct in a biomechanical sense.
27
Muscle origin
The origin is usually the proximal end of the muscle, which remains fixed.
28
Muscle insertion
The insertion is usually the distal end of the muscle, which is movable.
29
Types of skeletal muscle contraction
Reflexive contraction, tonic contraction, and phasic contraction
30
Reflexive contraction
A type of skeletal muscle contraction automatic and not voluntarily controlled—for example, respiratory movements of the diaphragm. Muscle stretch evokes reflexive contraction produced by tapping a tendon with a reflex hammer.
31
Tonic contraction
A type of skeletal muscle contraction which is a slight contraction (muscle tone) that does not produce movement or active resistance but
gives the muscle firmness, assisting the stability of joints and the maintenance of posture.
32
Phasic contraction
A type of skeletal muscle contraction.
Two types of phasic contraction: Isometric and isotonic
33
Isometric contractions
A type of phasic contraction where the muscle length remains the same—no movement occurs but muscle tension is increased above tonic levels (e.g., the deltoid holds the arm in abduction).
Force = Mass
34
Isotonic contraction
A type of phasic contraction where the muscle changes length to produce movement.
Two types:
Concentric contraction: Muscle shortening, Force \> Mass
Eccentric contraction: Muscle lengthening/relaxation of a contracted muscle, Force \< Mass
35
Muscular hydrostat
A biological machine
consisting mainly of muscles with no skeletal support.
Ex. human pharynx (throat), elephant trunk
36
Joint classification
Joints can be classified as synarthroses or diarthroses.
37
Diarthroses (synovial joints)
Joints that allow free
movement of the attached bones, such as knuckles, knees, and elbows.
38
Synarthrosis
Permits only limited movement.
Synostoses, syndesmoses, and symphyses
39
Synostoses
A type of synarthroses joint that allows essentially no movement between bones. In older adults synostoses unite the skull bones, which in children and young
adults are held together by sutures.
40
Syndesmoses
A type of synarthroses joint that joins bones by dense connective tissue only. E.g., the interosseous ligament of the inferior tibiofibular joint and the posterior
region of the sacroiliac joints.
41
Symphyses
A type of synarthroses joint that have a thick pad of fibrocartilage between the thin articular cartilage covering the ends of the bones. Examples include
intervertebral discs and the pubic symphysis.
42
Diarthroses (synovial joints) components
Articular capsule: Composed of fibrous layer and synovial membrane.
Synovial membrane lines the capsule and produces synovial fluid. Continuous with a ligament inserting into the periosteum of both bones;
Joint cavity containing synovial fluid lubricant
43
Rheumatoid arthritis
Chronic inflammation of the
synovial membrane of the joint causes thickening of
this connective tissue and stimulates the macrophages to release collagenases and other
hydrolytic enzymes.
44
Articular Cartilage
Proteoglycan aggregates bound to hyaluronan
form a hydrated megacomplex that acts as a biomechanical spring. This spring distributes forces evenly through the cartilage, and also causes movement of water within the cartilage.
When pressure is applied a small amount of water is forced out of the cartilage matrix into the synovial fluid. When pressure is released
water is attracted back into the interstices of the matrix. Such movements of water occur constantly with normal use of the joint, and are also important for nutrition of the cartilage, and for gas and metabolite exchange.
45
Intervertebral Disc
The disc consists of
concentric layers of fibrocartilage that form the annulus fibrosus, which surrounds the nucleus
pulposus.
The intervertebral discs function primarily as shock absorbers within the spinal column and allow greater
mobility within the spinal column.
46
Herniated Disc
Within an intervertebral disc, collagen loss or other degenerative changes in the annulus fibrosus are often accompanied by
displacement of the nucleus pulposus, a condition variously called a slipped or herniated disc. This occurs most frequently on the posterior region of the intervertebral disc where there are fewer collagen bundles.
47
Carpal tunnel syndrome
```
Results from any lesion that significantly reduces the size of the carpal tunnel or, more commonly, increases
the size of some of the structures (or their coverings) that pass
through it (e.g., inflammation of the synovial sheaths).
```
48
Force generated by a muscle is proportional to its \_\_\_\_\_\_\_\_
cross-sectional area
(the number of fibers
being fired).
49
What does contraction distance and rate of shortening depend on?
The number of sarcomeres. The contraction distance depends on the number of
sarcomeres. However, the number of sarcomeres
does not affect the contraction time of the muscle—each sarcomere contracts in the same unit of time.
50
Parallel muscles
Generate greater velocity but less force, because of smaller cross-sectional area.
But both parallel and pinnate muscles produce approximately the same amount of power.
P = W/t = F \* d/t = F \* V
51
Pinnate muscles
Have more force, less velocity.
But both parallel and pinnate muscles produce approximately the same amount of power.
P = W/t = F \* d/t = F \* V
52
Movement of a hinge joint is \_\_\_\_\_\_\_
uniaxial
53
Articular cartilage does not have a \_\_\_\_\_\_\_\_\_\_\_
perichondral covering
54
Which has higher muscle tension (force generated), isometric contraction or isotonic contraction?
Isometric contraction
55
The breast meat of a chicken is very white in color, whereas the breast meat of a wild duck is dark red. Why is the reason or reasons for this difference?
The difference reflects both function and the effects of breeding. Ducks fly long distances and so the meat has a higher percentage of Type I fibers, whereas chickens don't fly much and their breast muscle is mainly Type IIb. A second reason is that chickens are bred to have "whiter" white meat.
56
Which type of muscle fibers experience the most rapid fatigue?
Fast glycolytic (type 2b)
57
An entire skeletal muscle is enclosed within a thick layer of dense connective tissue called the \_\_\_\_\_\_\_\_\_
Epimysium
58
Muscles perform different classes of functions. A ________________ steadies the proximal parts of a limb while movements happens distally.
fixator
59
The distance that a muscle contracts depends on \_\_\_\_\_\_\_\_\_\_\_\_
The arrangement (parallel, pinnate, etc) and length of the muscle fibers.
60
Deltoid muscle has a ______ structural type
Multipennate
61
Sartorius muscle has a ______ structural type
Thin parallel
62
Biceps brachii muscles have a ______ structural type
Fusiform
63
Extensor digitorum longus muscles have a ______ structural type
Unipennate
64
Orbicularis oris muscle has a ______ structural type
Circular
65
Rectus femoris muscle has a ______ structural type
Bipennate
66
Pectoralis major muscle has a ______ structural type
Convergent
67
Rectus abdominis muscles have a ______ structural type
Quadrate
68
External oblique muscles have a ______ structural type
Flat parallel muscle with aponeurosis
69
Omohyoid muscle has a ______ structural type
Digastric
70
Supination of the wrist
During the motion of supination, the joint between the humerus and ulna maintains its position, while the head of the radius rotates on the distal condyle of the humerus.
71
# Reversed prompt
Mitochondria: Numerous
Capillaries: Numerous
Myoglobin content: High (red fibers)
Glycogen content: Low
Slow, Oxidative Fibers (Type 1) mitochondria, capillaries, myoglobin content, and glycogen content
72
# Reversed prompt
Mitochondria: Numerous
Capillaries: Numerous
Myoglobin content: High (red fibers)
Glycogen content: Intermediate
Fast, Oxidative-Glycolytic Fibers (Type 2a) mitochondria, capillaries, myoglobin content, and glycogen content
73
# Reversed prompt
Mitochondria: Sparse
Capillaries: Sparse
Myoglobin content: Low (white fibers)
Glycogen content: High
Fast, Glycolytic Fibers (Type 2b) mitochondria, capillaries, myoglobin content, and glycogen content
74
# Reversed prompt
Rate of fatigue: Slow
Speed of contraction: Slow
Major location: Postural muscles of back
Slow, Oxidative Fibers (Type 1) rate of fatigue, speed of contraction, and major locations
75
# Reversed prompt
Rate of fatigue: Intermediate
Speed of contraction: Fast
Major location: Major muscles of legs
Fast, Oxidative-Glycolytic Fibers (Type 2a) rate of fatigue, speed of contraction, and major locations
76
# Reversed prompt
Rate of fatigue: Fast
Speed of contraction: Fast
Major location: Extraocular muscles
Fast, Glycolytic Fibers (Type 2b) rate of fatigue, speed of contraction, and major locations
77
# Reversed prompt
Well vascularized and have lots of myoglobin, which stores oxygen. Myoglobin is an iron- and oxygen-storage protein found in cardiac and skeletal muscle.
Red fibers contract slowly and resist fatigue.
Red fibers
78
# Reversed prompt
Low in myoglobin; they contract quickly, but tire easily.
White fibers
79
# Reversed prompt
Type 1, type 2a, type2b
Three different motor units in the human body
80
# Reversed prompt
Highly fatigue resistant, has a lower activation threshold, contains fewer muscle fibers, and has low force generation during contraction.
Type 1 motor unit
81
# Reversed prompt
Resistant to fatigue, has a higher activation threshold, and the force produced is higher compared to type 1
Type 2 motor unit
82
# Reversed prompt
Fatigable, has a high activation threshold, innervates the most muscle fibers, and generates the greatest force during contraction
Type 2b motor unit
83
# Reversed prompt
muscle fiber
The structural unit of a muscle is a \_\_\_\_\_\_\_
84
# Reversed prompt
motor unit
The functional unit of a muscle, consisting of a motor neuron and the muscle fibers it controls, is a \_\_\_\_\_\_\_
85
# Reversed prompt
A band or sheet of connective tissue, that attaches, encloses, and separates muscles and other internal organs. It interpenetrates and
surrounds the muscles, bones, nerves, and blood vessels of the body.
Fascia
86
# Reversed prompt
Fascia is classified by layer as superficial fascia, deep fascia, and visceral or
parietal fascia, or by its function and anatomical location.
How is fascia classified?
87
# Reversed prompt
Associated with, bone (periosteum and endosteum), cartilage (perichondrium), blood vessels (tunica externa), muscles (epimysium, perimysium, and endomysium), nerves (epineurium, perineurium, and endoneurium)
High density of elastin fiber for extensibility and resilience
Deep fascia
88
# Reversed prompt
Often surrounds groups of muscles, forming compartments.
Fasciae also reduce friction between muscles and blood vessels and nerves.
Fascia function
89
# Reversed prompt
Prime mover or agonist, fixators, synergist, antagonist
Muscle functions (broad sense)
90
# Reversed prompt
The main muscle responsible for producing a specific movement of the body (e.g., concentric contraction).
Prime mover or agonist
91
# Reversed prompt
Steady the proximal parts of a limb while movements are occurring in distal parts.
Fixators
92
# Reversed prompt
Complements the action of prime movers—for
example, by preventing movement of the intervening joint when a prime mover passes over more than one joint.
Synergist
93
# Reversed prompt
A muscle that opposes the action of a prime mover. As a prime mover contracts, the antagonist progressively relaxes, producing a smooth movement.
Antagonist
94
# Reversed prompt
Flexors and extensors, abductors and adductors
Functions (narrow sense)
95
# Reversed prompt
When muscles contract, the fibers shorten to about 70% of their resting length. Muscles with a long parallel fascicle arrangement shorten the most, providing considerable range of movement at a joint, but are not powerful.
What muscles shorten the most during contraction?
96
# Reversed prompt
Muscle power increases as the total number of muscle cells increases. Therefore, the shorter, wide pennate muscles that “pack in” the most fiber bundles shorten less but are most powerful.
This statement is not quite correct in a biomechanical sense.
Muscle power
97
# Reversed prompt
The origin is usually the proximal end of the muscle, which remains fixed.
Muscle origin
98
# Reversed prompt
The insertion is usually the distal end of the muscle, which is movable.
Muscle insertion
99
# Reversed prompt
Reflexive contraction, tonic contraction, and phasic contraction
Types of skeletal muscle contraction
100
# Reversed prompt
A type of skeletal muscle contraction automatic and not voluntarily controlled—for example, respiratory movements of the diaphragm. Muscle stretch evokes reflexive contraction produced by tapping a tendon with a reflex hammer.
Reflexive contraction
101
# Reversed prompt
A type of skeletal muscle contraction which is a slight contraction (muscle tone) that does not produce movement or active resistance but
gives the muscle firmness, assisting the stability of joints and the maintenance of posture.
Tonic contraction
102
# Reversed prompt
A type of skeletal muscle contraction.
Two types of phasic contraction: Isometric and isotonic
Phasic contraction
103
# Reversed prompt
A type of phasic contraction where the muscle length remains the same—no movement occurs but muscle tension is increased above tonic levels (e.g., the deltoid holds the arm in abduction).
Force = Mass
Isometric contractions
104
# Reversed prompt
A type of phasic contraction where the muscle changes length to produce movement.
Two types:
Concentric contraction: Muscle shortening, Force \> Mass
Eccentric contraction: Muscle lengthening/relaxation of a contracted muscle, Force \< Mass
Isotonic contraction
105
# Reversed prompt
A biological machine
consisting mainly of muscles with no skeletal support.
Ex. human pharynx (throat), elephant trunk
Muscular hydrostat
106
# Reversed prompt
Joints can be classified as synarthroses or diarthroses.
Joint classification
107
# Reversed prompt
Joints that allow free
movement of the attached bones, such as knuckles, knees, and elbows.
Diarthroses (synovial joints)
108
# Reversed prompt
Permits only limited movement.
Synostoses, syndesmoses, and symphyses
Synarthrosis
109
# Reversed prompt
A type of synarthroses joint that allows essentially no movement between bones. In older adults synostoses unite the skull bones, which in children and young
adults are held together by sutures.
Synostoses
110
# Reversed prompt
A type of synarthroses joint that joins bones by dense connective tissue only. E.g., the interosseous ligament of the inferior tibiofibular joint and the posterior
region of the sacroiliac joints.
Syndesmoses
111
# Reversed prompt
A type of synarthroses joint that have a thick pad of fibrocartilage between the thin articular cartilage covering the ends of the bones. Examples include
intervertebral discs and the pubic symphysis.
Symphyses
112
# Reversed prompt
Articular capsule: Composed of fibrous layer and synovial membrane.
Synovial membrane lines the capsule and produces synovial fluid. Continuous with a ligament inserting into the periosteum of both bones;
Joint cavity containing synovial fluid lubricant
Diarthroses (synovial joints) components
113
# Reversed prompt
Chronic inflammation of the
synovial membrane of the joint causes thickening of
this connective tissue and stimulates the macrophages to release collagenases and other
hydrolytic enzymes.
Rheumatoid arthritis
114
# Reversed prompt
Proteoglycan aggregates bound to hyaluronan
form a hydrated megacomplex that acts as a biomechanical spring. This spring distributes forces evenly through the cartilage, and also causes movement of water within the cartilage.
When pressure is applied a small amount of water is forced out of the cartilage matrix into the synovial fluid. When pressure is released
water is attracted back into the interstices of the matrix. Such movements of water occur constantly with normal use of the joint, and are also important for nutrition of the cartilage, and for gas and metabolite exchange.
Articular Cartilage
115
# Reversed prompt
The disc consists of
concentric layers of fibrocartilage that form the annulus fibrosus, which surrounds the nucleus
pulposus.
The intervertebral discs function primarily as shock absorbers within the spinal column and allow greater
mobility within the spinal column.
Intervertebral Disc
116
# Reversed prompt
Within an intervertebral disc, collagen loss or other degenerative changes in the annulus fibrosus are often accompanied by
displacement of the nucleus pulposus, a condition variously called a slipped or herniated disc. This occurs most frequently on the posterior region of the intervertebral disc where there are fewer collagen bundles.
Herniated Disc
117
# Reversed prompt
```
Results from any lesion that significantly reduces the size of the carpal tunnel or, more commonly, increases
the size of some of the structures (or their coverings) that pass
through it (e.g., inflammation of the synovial sheaths).
```
Carpal tunnel syndrome
118
# Reversed prompt
cross-sectional area
(the number of fibers
being fired).
Force generated by a muscle is proportional to its \_\_\_\_\_\_\_\_
119
# Reversed prompt
The number of sarcomeres. The contraction distance depends on the number of
sarcomeres. However, the number of sarcomeres
does not affect the contraction time of the muscle—each sarcomere contracts in the same unit of time.
What does contraction distance and rate of shortening depend on?
120
# Reversed prompt
Generate greater velocity but less force, because of smaller cross-sectional area.
But both parallel and pinnate muscles produce approximately the same amount of power.
P = W/t = F \* d/t = F \* V
Parallel muscles
121
# Reversed prompt
Have more force, less velocity.
But both parallel and pinnate muscles produce approximately the same amount of power.
P = W/t = F \* d/t = F \* V
Pinnate muscles
