Chp 12 -- Skeletal Muscle Flashcards Preview

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Flashcards in Chp 12 -- Skeletal Muscle Deck (111)
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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
Q

sum of passive and active forces

A

total force

26
Q

when muscle fibers that are developing tension are stimulated again before the fibers have relaxed

A

wave summation

27
Q

The three phases of a muscle twitch are the contraction period, the relaxation period, and the:

A

latent phase

28
Q

The endoplasmic reticulum of a muscle cell is called

A

sarcoplasmic reticulum (SR)

29
Q

plasma membrane of the muscle fiber

A

sarcolemma

30
Q

From what cellular organelle is calcium released during the latent period of a muscle twitch?

A

sarcoplasmic reticulum

31
Q

Each muscle fiber is surrounded by thin connective tissue called the ____.

A

endomysium

32
Q

Identify the indicated structure.

A

sarcoplasmic reticulum

33
Q

What type of force is produced by the elastic recoil of a stretched muscle?

A

passive

34
Q

In what way is the stimulation of a muscle to produce treppe different from stimulation to produce summation?

A

treppe

35
Q

Membrane potential changes from the _______ travel along the T tubules to the _____ and signals the release of calcium from the SR, which initiates _______.

A

sarcolemma; triads; contraction

36
Q

The absence of what molecule is involved in the phenomenon of rigor mortis?

A

ATP

37
Q

a skeletal muscle produces what when nervous or electrical stimulation is applied

A

tension (a.k.a. muscle force)

38
Q

bundle of muscle fibers

A

fascicle

39
Q

if the muscle shortens as the load moves, the contraction is called

A

isotonic concentric contraction

40
Q

* 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

A

fatigue

41
Q

when stimuli frequency reaches a value beyond which no further increases in forces are generated by the muscle

A

maximal tetanic tension

42
Q

In sarcomeres, what corresponds to the light striations?

A

I band

43
Q

Identify the indicated region of the sarcomere.

A

A-band

44
Q

What experimental factor do we increase to produce tetany rather than simple wave summation?

A

frequency of stimulation

45
Q

In sarcomeres, what corresponds to the dark striations?

A

A band

46
Q

Immovable attachment site of a muscle is called the _____

A

origin

47
Q

a long organelle with a banded appearance found within muscle fibers

A

myofibril

48
Q

maximal tension in the whole muscle occurs when all the muscle fibers have been activated by a sufficiently strong stimulus

A

maximal voltage

49
Q

What phenomenon is considered an extreme form of wave summation in which a steady, sustained contraction is achieved?

A

tetanus, tetany

50
Q

Flat sheets of the tendon are called _________.

A

aponeuroses

51
Q

isometric

A

same length

52
Q

Identify the indicated layer of connective tissue.

A

endomysium

53
Q

Identify the indicated structure.

A

muscle fiber

54
Q

rise in muscle tension but no observable movement of the weight

A

latent period

55
Q

maximum possible from each stimulus will eventually reach a plateau

A

unfused tetanus

56
Q

a single stimulated contraction of the whole skeletal muscle

A

muscle twitch

57
Q

In skeletal muscle, the signal that initiates contraction is always ________, meaning it comes from the _______.

A

neurogenic; motor neuron

58
Q

the mechanical response to a single action potential

A

muscle twitch

59
Q

In sarcomeres, what anchors to the proteins of the Z disc on one end?

A

thin filaments

60
Q

a graph relating the three forces generated and the fixed length of the muscle

A

isometric length-tension relationship

61
Q

Muscles contain ______________ and ___________ tissues.

A

skeletal muscle; regular connective

62
Q

Name parts #1-3

A

1: Part of skeletal muscle fiber (cell)

Left image 2: sarcolemma

Right image 2: I band

3: A band

63
Q

a process where the end-plate potential triggers a series of events that results in the contraction of the muscle cell

A

excitation-contraction coupling

64
Q

What type of force is produced by the elastic recoil of a stretched muscle?

A

passive

65
Q

The SR surrounds each _____ so that calcium can reach the ___________.

A

myofibril; contractile machinery

66
Q

Name parts #1-3

A

1: Z disc
2: M line
3: Z disc

67
Q

cord of collagen fibers that attaches a muscle to a bone

A

tendon

68
Q

What type of force is produced by the physiological contraction of a muscle rather than by elastic recoil?

A

active

69
Q

Name parts #7-9

A

7: blood vessel
8: endomysium
9: muscle fiber (cell)

70
Q

A cordlike structure that connects a muscle to another muscle or bone is _____.

A

a tendon

71
Q

Individual muscles are ______.

A

Organs

72
Q

Name parts #4-6

A

4: thin (actin) filament
5: elastic (titin) filaments
6: thick (myosin) filament

73
Q

thin aerolar connecive tissue surrounding each muscle fiber

A

endomysium

74
Q

Name parts #1-3

A

1: tendon
2: epimysium
3: endomysium (between fibers)

75
Q

Name parts #7-9

A

7: M line
8: Z disc
9: sarcolemma

76
Q

Name parts #7-9

A

7: thin (actin) filament
8: thick (myosin) filament
9: I band

77
Q

skeletal muscle length changes and load moves a measurable distance

A

isotonic contraction

78
Q

Identify the indicated structure.

A

fascicle

79
Q

the rate of stimulus delivery to the muscle

A

stimulus frequency

80
Q

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

A

complete (fused) tetanus

81
Q

A ___________, which is continuous with the sarcolemma, also runs along each myofibril at the Z disc.

A

transverse tubule (T tubule)

82
Q

The SR stores ______ and release them whenever a change in the membrane potential signals the start of a muscle contraction.

A

calcium ions

83
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

84
Q

In sarcomeres, what forms the thin filaments that overlap the thick filaments?

A

actin

85
Q

Name parts #10-12

A

10: A band
11: I band
12: sarcomere

86
Q

Identify the indicated region of the sarcomere.

A

A-band

87
Q

Blood vessels and nerves travel through the ________.

A

perimysium

88
Q

The contractile unit of muscle is ______.

A

sacromere

89
Q

Name #13-15.

A

13: dark A band
14: Light I band
15: nucleus

90
Q

the smallest stimulus required to induce an action potential in a muscle fiber’s plasma membrane

A

threshold voltage

91
Q

connective tissue covering a bundle of muscle fibers

A

perimysium

92
Q

List two of the seven criteria listed in your lab manual that are used to name muscles?

A

direction of muscle fibers

relative size

location

number of origins

location of origin and insertion

shape

action

93
Q

Identify the type of muscle tissue shown?

A

Smooth

94
Q

What neurotransmitter do motor neurons use to stimulate muscle cells?

A

acetylcholine

95
Q

If a muscle contracts against a load that it is able to lift, what type of contraction is the muscle demonstrating?

A

isotonic

96
Q

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?

A

treppe

97
Q

If a muscle contracts against a load that is too heavy for the muscle to lift, what type of contraction is the muscle demonstrating?

A

isometric

98
Q

What do we call muscles that oppose or reverse a particular movement?

A

antagonists

99
Q

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?

A

treppe

100
Q

What do we call muscles that immobilize the origin of another muscle so that all of the tension is exerted at the insertion?

A

fixators

101
Q

Name one action of the semitendinosus muscle.

A

extension of thigh

flexion of leg

medial rotation of leg

102
Q

Name one action of the trapezius muscle.

A

extension of head

elevation of scapula

rotation of scapula

adduction of scapula

103
Q

Name one action of the biceps brachii muscle.

A

flexion of forearm

supination of forearm

104
Q

Name one insertion of the supraspinatus muscle.

A

greater tubercle of humerus

105
Q

Name one insertion of the biceps brachii muscle.

A

radial tuberosity

106
Q

Name one insertion of the orbicularis oculi muscle.

A

eyelid

107
Q

Name one insertion of the flexor carpi radialis muscle.

A

base of metacarpals II and III

108
Q

Name one origin of the gastrocnemius muscle.

A

medial and lateral condyles of femur

109
Q

Name one origin of the supraspinatus muscle. Name one origin of the supraspinatus muscle.

A

supraspinous fossa of scapula

110
Q

Identify the indicated muscle.

A

semimembranosus

111
Q

Identify the indicated muscle.

A

extensor digitorum longus

peroneus