Chp 12 -- Skeletal Muscle Flashcards
(111 cards)
1
Q
Because the cells of skeletal muscle are relatively large and cylindrical in shape, they are also known as ____.
A
fibers
2
Q
Over each Z disc, the SR forms the thickened areas called the __________.
A
terminal cisternae
3
Q
the force generated by whole muscle reflects the # of active ______ at a given time
A
motor units
4
Q
Name parts #4-6
A
4: Z-disc
5: H Zone
6: Z-disc
5
Q
What type of force is produced by the physiological contraction of a muscle rather than by elastic recoil?
A
active
6
Q
a process that when the # of active motor units increases, there is a steady increase in muscle force produced
A
motor unit recruitment
7
Q
Name parts #10-12
A
10: triad
11: mitochondria
12: myofibrils
8
Q
Name parts #13-16
A
13: tubules of sarcoplasmic reticulum
14: terminal cisterna of the sarcoplasmic reticulum
15: T tubule
16: myofibril
9
Q
Name parts #1-3
A
1: sarcolemma
2: mitochondrion
3: myofibril
10
Q
Name parts #4-6
A
4: bone
5: perimysium
6: fascicle (wrapped by perimysium)
11
Q
The movable attachment site of a muscle is called ___.
A
insertion
12
Q
The junction between an axon and a muscle fiber is called a ____.
A
neuromuscular junction
13
Q
Fascicles are covered by a connective tissue sheath called the ___________.
A
perimysium
14
Q
If we place a muscle under more load than it can lift and stimulate it, what type of contraction will we produce?
A
isometric
15
Q
contractile of unit of muscle
A
sacromere
16
Q
isolated skeletal muscle resulting in an increase in force produced by the whole muscle
A
stimulus frequency
17
Q
actin- or myosin-containing structure
A
myofilament
18
Q
Identify the indicated region of the sarcomere.
A
H-zone
19
Q
Motor neurons release the neurotransmitter ________ onto the sarcolemma.
A
acetylcholine
20
Q
Name parts #10-12
A
10:
11:
12:
21
Q
Name parts #4-6
A
4: I band
5: Z disc
6: H zone
22
Q
as the ______ to a muscle is increased beyond the threshold voltage, the amount of force produced by the whole muscle also increases
A
stimulus voltage
23
Q
superficial sheath that covers the entire muscle
A
epimysium
24
Q
If we place a muscle under a load than it can lift and stimulate it, what type of contraction will we produce?
A
isotonic
25
sum of passive and active forces
total force
26
when muscle fibers that are developing tension are stimulated again before the fibers have relaxed
wave summation
27
The three phases of a muscle twitch are the contraction period, the relaxation period, and the:
latent phase
28
The endoplasmic reticulum of a muscle cell is called
sarcoplasmic reticulum (SR)
29
plasma membrane of the muscle fiber
sarcolemma
30
From what cellular organelle is calcium released during the latent period of a muscle twitch?
sarcoplasmic reticulum
31
Each muscle fiber is surrounded by thin connective tissue called the \_\_\_\_.
endomysium
32
Identify the indicated structure.
sarcoplasmic reticulum
33
What type of force is produced by the elastic recoil of a stretched muscle?
passive
34
In what way is the stimulation of a muscle to produce treppe different from stimulation to produce summation?
treppe
35
Membrane potential changes from the _______ travel along the T tubules to the _____ and signals the release of calcium from the SR, which initiates \_\_\_\_\_\_\_.
sarcolemma; triads; contraction
36
The absence of what molecule is involved in the phenomenon of rigor mortis?
ATP
37
a skeletal muscle produces what when nervous or electrical stimulation is applied
tension (a.k.a. muscle force)
38
bundle of muscle fibers
fascicle
39
if the muscle shortens as the load moves, the contraction is called
isotonic concentric contraction
40
\* failure of a muscle fiber to produce tension because of previous contractile activity;
\* a decline in the muscle's ability to maintain a constant force of contraction after prolonged, repetitive stimulation
fatigue
41
when stimuli frequency reaches a value beyond which no further increases in forces are generated by the muscle
maximal tetanic tension
42
In sarcomeres, what corresponds to the light striations?
I band
43
Identify the indicated region of the sarcomere.
A-band
44
What experimental factor do we increase to produce tetany rather than simple wave summation?
frequency of stimulation
45
In sarcomeres, what corresponds to the dark striations?
A band
46
Immovable attachment site of a muscle is called the \_\_\_\_\_
origin
47
a long organelle with a banded appearance found within muscle fibers
myofibril
48
maximal tension in the whole muscle occurs when all the muscle fibers have been activated by a sufficiently strong stimulus
maximal voltage
49
What phenomenon is considered an extreme form of wave summation in which a steady, sustained contraction is achieved?
tetanus, tetany
50
Flat sheets of the tendon are called \_\_\_\_\_\_\_\_\_.
aponeuroses
51
isometric
same length
52
Identify the indicated layer of connective tissue.
endomysium
53
Identify the indicated structure.
muscle fiber
54
rise in muscle tension but no observable movement of the weight
latent period
55
maximum possible from each stimulus will eventually reach a plateau
unfused tetanus
56
a single stimulated contraction of the whole skeletal muscle
muscle twitch
57
In skeletal muscle, the signal that initiates contraction is always \_\_\_\_\_\_\_\_, meaning it comes from the \_\_\_\_\_\_\_.
neurogenic; motor neuron
58
the mechanical response to a single action potential
muscle twitch
59
In sarcomeres, what anchors to the proteins of the Z disc on one end?
thin filaments
60
a graph relating the three forces generated and the fixed length of the muscle
isometric length-tension relationship
61
Muscles contain ______________ and ___________ tissues.
skeletal muscle; regular connective
62
Name parts #1-3
1: Part of skeletal muscle fiber (cell)
Left image 2: sarcolemma
Right image 2: I band
3: A band
63
a process where the end-plate potential triggers a series of events that results in the contraction of the muscle cell
excitation-contraction coupling
64
What type of force is produced by the elastic recoil of a stretched muscle?
passive
65
The SR surrounds each _____ so that calcium can reach the \_\_\_\_\_\_\_\_\_\_\_.
myofibril; contractile machinery
66
Name parts #1-3
1: Z disc
2: M line
3: Z disc
67
cord of collagen fibers that attaches a muscle to a bone
tendon
68
What type of force is produced by the physiological contraction of a muscle rather than by elastic recoil?
active
69
Name parts #7-9
7: blood vessel
8: endomysium
9: muscle fiber (cell)
70
A cordlike structure that connects a muscle to another muscle or bone is \_\_\_\_\_.
a tendon
71
Individual muscles are \_\_\_\_\_\_.
Organs
72
Name parts #4-6
4: thin (actin) filament
5: elastic (titin) filaments
6: thick (myosin) filament
73
thin aerolar connecive tissue surrounding each muscle fiber
endomysium
74
Name parts #1-3
1: tendon
2: epimysium
3: endomysium (between fibers)
75
Name parts #7-9
7: M line
8: Z disc
9: sarcolemma
76
Name parts #7-9
7: thin (actin) filament
8: thick (myosin) filament
9: I band
77
skeletal muscle length changes and load moves a measurable distance
isotonic contraction
78
Identify the indicated structure.
fascicle
79
the rate of stimulus delivery to the muscle
stimulus frequency
80
stimuli applied with greater frequency which have twitches beginning to twitch and fuse so peaks and valleys of each twitch become indistinguishable from one another
complete (fused) tetanus
81
A \_\_\_\_\_\_\_\_\_\_\_, which is continuous with the sarcolemma, also runs along each myofibril at the Z disc.
transverse tubule (T tubule)
82
The SR stores ______ and release them whenever a change in the membrane potential signals the start of a muscle contraction.
calcium ions
83
If we place a muscle under a load than it can lift and stimulate it, what type of contraction will we produce?
isotonic
84
In sarcomeres, what forms the thin filaments that overlap the thick filaments?
actin
85
Name parts #10-12
10: A band
11: I band
12: sarcomere
86
Identify the indicated region of the sarcomere.
A-band
87
Blood vessels and nerves travel through the \_\_\_\_\_\_\_\_.
perimysium
88
The contractile unit of muscle is \_\_\_\_\_\_.
sacromere
89
Name #13-15.
13: dark A band
14: Light I band
15: nucleus
90
the smallest stimulus required to induce an action potential in a muscle fiber's plasma membrane
threshold voltage
91
connective tissue covering a bundle of muscle fibers
perimysium
92
List two of the seven criteria listed in your lab manual that are used to name muscles?
direction of muscle fibers
relative size
location
number of origins
location of origin and insertion
shape
action
93
Identify the type of muscle tissue shown?
Smooth
94
What neurotransmitter do motor neurons use to stimulate muscle cells?
acetylcholine
95
If a muscle contracts against a load that it is able to lift, what type of contraction is the muscle demonstrating?
isotonic
96
If we stimulate a muscle, and then stimulate it again immediately after it has been allowed to relax, we observe that the second contraction of the muscle is slightly greater than the first. What do we call this phenomenon?
treppe
97
If a muscle contracts against a load that is too heavy for the muscle to lift, what type of contraction is the muscle demonstrating?
isometric
98
What do we call muscles that oppose or reverse a particular movement?
antagonists
99
If we stimulate a muscle, and then stimulate it again immediately after it has been allowed to relax, we observe that the second contraction of the muscle is slightly greater than the first. What do we call this phenomenon?
treppe
100
What do we call muscles that immobilize the origin of another muscle so that all of the tension is exerted at the insertion?
fixators
101
Name one action of the semitendinosus muscle.
extension of thigh
flexion of leg
medial rotation of leg
102
Name one action of the trapezius muscle.
extension of head
elevation of scapula
rotation of scapula
adduction of scapula
103
Name one action of the biceps brachii muscle.
flexion of forearm
supination of forearm
104
Name one insertion of the supraspinatus muscle.
greater tubercle of humerus
105
Name one insertion of the biceps brachii muscle.
radial tuberosity
106
Name one insertion of the orbicularis oculi muscle.
eyelid
107
Name one insertion of the flexor carpi radialis muscle.
base of metacarpals II and III
108
Name one origin of the gastrocnemius muscle.
medial and lateral condyles of femur
109
Name one origin of the supraspinatus muscle. Name one origin of the supraspinatus muscle.
supraspinous fossa of scapula
110
Identify the indicated muscle.
semimembranosus
111
Identify the indicated muscle.
extensor digitorum longus
peroneus
