Unit 2 PPT Flashcards
(125 cards)
1
Q
What does a extensibility and elasticity do
A
Enabled the muscle to be stressed and return the normal length
2
Q
What are tendons continuations of
A
Muscles connective tissue and also possess extensibility and elasticity
3
Q
Contractility
A
The ability to shorten and produced tension
4
Q
Muscle functions
A
Flexibility
Strength
Power
Endurance
5
Q
What does muscle fiber consist of
A
Myofibrils held together by sarcolemma that can propagate nerve impulses
6
Q
How are myofibrils arranged
A
in parallel formation
7
Q
what are myofibrils made up of
make appearance
A
alternating dark and light bands that give muscle fiber their striated appearance
8
Q
what is myofibrils enclosed in
A
endomysium
9
Q
what does actin do when stimulated
A
slides over myosin
10
Q
cross bridges
A
projections of myosin attached to actin
11
Q
what is a myofibril
A
any of the elongated contractile threads found in striated muscle cells.
consists of a series of sarcomeres
12
Q
Concentric contractions
A
Oppose gravity
Action as indicated
Muscles shortens under tension
13
Q
eccentric contractions
A
with gravity
action of opposite muscle group
muscle lengthens under tesion
14
Q
type I muscle fiber
A
slow oxidative
15
Q
type IIa muscle fiber
A
fast oxidative glycolytic
16
Q
type IIb muscle fiber
A
fast glycolytic
17
Q
type 1 slow twitch
characteristics
A
smaller, red greater blood supply more myoglobin more resistant to fatigue aerobic
18
Q
type IIb
characteristics
A
large, pale less blood supply less myoglobin fatigue easier anaerobic
19
Q
what do most limb muscles contain
A
relatively equal distribution of each muscle fiber
20
Q
what do postural muscles contain more of
A
slow twitch fibers
21
Q
sarcomere
A
contractile unit of skeletal muscle
22
Q
hyperplasia
A
increase number of fibers
23
Q
hypertrophy
A
fibers get larger in size
24
Q
Reverse muscle action
A
Occurs when the distal bone is stabilized and the proximal bone moves
25
Shows what muscle action will occur
Attachment location
Angle of pull
Number of articulations crossed
26
What determines movement
Type of joint
| Spatial relationships
27
Classification by movement muscles
flexors, extensors
abductors, adductors
rotators
28
fusiform
| classification by fiber arrangement
muscle fibers parallel to long axis
29
what can fusiform include
longitudinal, quadrate, trianglur
30
pennate
| classification by fiber arrangement
fibers extend from central tendon
31
what can pennate include
unipenniform
bipenniform
multipenniform
32
Longitudinal muscle
long, strap like muscle with fibers in parallel to its axis
33
example of longitudinal muscle
sartorius
34
quadrate or quadrilateral
four sided and usually flat
35
example of quadrate muscle
rhomboids
36
triangular
fibers radiate from a narrow attachment at one end to a broad attachment at the other end
37
example of triangular muslce
pectoralis major
38
fusiform or "spindle"
rounded muscle that tapers at either end
39
example of fusiform muscle
brachioradialis
40
unipennate
a series of short, parallel, feather like fibers extends diagonally from the side of a long tendon
41
example of unipennate muslce
tibialis posterior
42
bipennate
long central tendon with fibers extending diagonally in pairs from either side of the tendon
43
example of bipennate muscle
rectus femoris
44
multipennate
several tendons are present, with fibers running diagonally between them
45
example of multipennate muslce
middle deltoid
46
mechanical advantage of fusiform
longer fibers
greater ROM
less force production
47
mechanical advantage of pennate
shorter fibers
less ROM
greater force production
48
What is proportional two its physiological cross section
Force a muscle can exert
49
do broad, thick, longitudinal muscle or thin muscle exert more force
broad, thick, longitudinal muslces
50
does a pennate muscle or a longitudinal muscle of same thickness exert a greater force
pennate muscle
51
why does a pennate muscle exert more force than a longitudinal muscle of same thickness
the oblique arrangement of the fiber allows for a larger number of fibers
52
how much can a muscle shorten to
approximately half its resting length
53
what long muscles with fibers longitudinally arranged along the long axis do
exert force over a longer distance
54
what can pennate muscles with their oblique fiber arrangement and short fibers do
exert superior force through only a short range
55
Types of muscle contractions
```
Concentric
eccentric
isometric
isotonic
isokinetic
```
56
concentric
muscle shortens with tension
| weight against gravity
57
eccentric
muscle lengthens with tension
| weight with gravity
58
isometric
| occurs
tension but no movement
| tension is developed in the muscle without any appreciable change in length
59
isotonic
constant tension through ROM
| equal tension
60
isokinetic
maximum tension through ROM
| equal or same motion
61
example of isokinetic
cybex, biodex, nautilis
62
example of isotonic
free weights
63
what does contract mean literally
draw together
64
when does muscle contraction occur
whenever muscle fibers generate tension which may occur while the muscle is actually shortening, remaining the same length, or lengthening
65
when does concentric or shortening contraction occur
when tension by the muscle is sufficient to overcome a resistance and move the body segment
66
how does eccentric or lengthening contractions occur
when a muscle slowly lengthens as it gives in to an external force that is greater than the contractile force it is exerting
67
what does a muscle act like during eccentric contraction
a brake
68
when does isometric contraction occurs under what 2 conditions
antagonistic muscles contract with equal strength
| muscle is held against another force
69
how does isotonic contraction occur
tension remains constant while muscle shortens or lengthens
70
how does a isokinetic contraction occcur
maximum muscle effort at the same speed
| accomodating resistance
71
movement to gravity
```
in same direction (downward)
opposing gravity (upward)
perpendicular to gravity (horizontal)
```
72
is horizontal motion affected by gavity
no
73
what kind of contraction does lifting against gravity require
concentric contraction
74
what kind of contraction does slowly lowering with gravity require
eccentric contraction
75
what does forceful downward motion use
agonist muscles in concentric contraction
76
tension length relationship
optimum length at which a muscle can exert maximum tension is generally slightly longer than the resting length of that muscle
77
relationship to angle of pull in length tension relationship
physiological advantage
| 90 degree angle of pull
78
force velocity relationship concentric contraction
as speed of a muscular contraction increases, the force it is able to exert decreases, as the speed of the contraction decreases, more force can be exerted
79
what do both muscle and tendon posses
elastic properties
80
what happens when concentric contraction is preceded by a phase of active stretching
elastic energy stored in the stretch phase is available for use in the contractile phase
81
movers or agnonists
directly responsible for producing movement
82
prime movers
large impact on movement
83
assistant movers
only help when needed
84
contralateral muscle
antagonist
| opposite side of joint
85
stabilizing muscles
fixators, support
86
true synergy
joint stabilization
antagonist
two joint muscles
87
helping synergy
joint movement
agonist
one joint or two joint muslces
88
synergists
cooperative muscle function
| stablizing, fixator and support muscles
89
neutralizers
prevent undesired action
90
antagonists
have an effect opposite to that of movers, or agonists
91
2 things antagonists do
relax to permit movement
| act as a brake at completion of movement
92
cocontraction
simultaneous contraction of movers and antagonists
93
what do neutralizers and stabilizers need
cocontract to counteract the additional function of a mover
94
is spurt or shunt muscle more active
spurt
95
spurt muscle
rotary
96
shunt muscle
stabilizing
97
origin 1 > insertion 1
spurt
98
origin 2 < insertion 2
shunt
99
pulley action
transmits tension from one muscle to the opposite muscle
100
2 major advantages of two joint muscle
ability to exert force without losing tension
| can exert tension without shortening due to pulley action of tendons
101
action of bi-articular muscles
muscles that pass over and act on two joints
whether muscles flex joints in the same direction or opposite directions, they are not long enough to permit complete movement in both joints at the same time
resulting tension in one muscle is transmitted to the other
102
what can bi articular muscles do
continue to exert tension without shortening
103
concurrent movement
same action occurs at both joints of the two joint muscle
104
counterconcurrent movement
opposite action occurs at both joints of the two joint muscle
105
example of concurrent movement
hip extension and knee extension
106
example of counterconcurrent movement
hip flexion and knee extension
107
concurrent action
no net change in length of either muslce
108
countercurrent action
one muscle shortens at both joints as the antagonists lengthens correspondingly and thereby gains tension at both ends
109
ballistic movement
movements that are initiated by vigorous contraction and completed by momentum
110
example of ballistic movement
throwing, striking, kicking
111
what should you do in the early stages of learning ballistic movement
concentrate on form rather than accuracy
112
3ways termination of ballistic action occurs
by contracting antagonist muscle
by passive resistance of ligaments or other tissues at limits of motion
by the interference of an obstacle
113
example of contracting antagonist muscles
forehand drive in tennis
114
example of passive resistance of ligaments or other tissues at limits of motion
throwing motion
115
example of interference of an obstacle
chopping wood
116
methods of studying actions of muscle
```
conjecture & reasoning
dissection
inspection & palpation
models & gadgets
muscle stimulation
electromyography (EMG)
```
117
conjecture & reasoning
using an educated guess
118
dissection
meaningful basis for visualization of muscle's potential movement
119
inspection & palpation
valuable method for superficial muscles
120
models
used for demonstration
121
muscle stimulation
contraction of individual muscles
| uses outside source of electrical stimulation
122
electromyography
based on the fact that contracting muscles generate electrical impules
reveals both intensity and duration of muscle activity
cannot indicate nature of contraction or muscle action
123
if angle of attachment is very shallow,
most of the tendon will produce a force alone the bone
124
if angle of attachment is fairly large
will have a much larger rotary component of force
125
what happens if angle of attachment has many muscles
| in many muscles
the angle changes throughout ROM
| what muscle generates tension at 90 degree angle to the bone, it i the most efficient at producing joint motion
