Chp 12 -- Skeletal Muscle Flashcards Preview

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Flashcards in Chp 12 -- Skeletal Muscle Deck (111)
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1

Because the cells of skeletal muscle are relatively large and cylindrical in shape, they are also known as ____.

fibers

2

Over each Z disc, the SR forms the thickened areas called the __________.

terminal cisternae

3

the force generated by whole muscle reflects the # of active ______ at a given time

motor units

4

Name parts #4-6

4: Z-disc

5: H Zone

6: Z-disc 

5

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

active

6

a process that when the # of active motor units increases, there is a steady increase in muscle force produced

motor unit recruitment

7

Name parts #10-12

10: triad

11: mitochondria

12: myofibrils

8

Name parts #13-16

13: tubules of sarcoplasmic reticulum

14: terminal cisterna of the sarcoplasmic reticulum

15: T tubule

16: myofibril

9

Name parts #1-3

1: sarcolemma

2: mitochondrion

3: myofibril

10

Name parts #4-6

4: bone

5: perimysium

6: fascicle (wrapped by perimysium)

11

The movable attachment site of a muscle is called ___.

insertion

12

The junction between an axon and a muscle fiber is called a ____.

neuromuscular junction

13

Fascicles are covered by a connective tissue sheath called the ___________.

perimysium

14

If we place a muscle under more load than it can lift and stimulate it, what type of contraction will we produce?

isometric

15

contractile of unit of muscle

sacromere

16

isolated skeletal muscle resulting in an increase in force produced by the whole muscle

stimulus frequency

17

actin- or myosin-containing structure

myofilament

18

Identify the indicated region of the sarcomere. 

H-zone

 

19

Motor neurons release the neurotransmitter ________ onto the sarcolemma.

acetylcholine

20

Name parts #10-12

10: 

11:

12:

 

21

Name parts #4-6

4: I band

5: Z disc

6: H zone

22

as the ______ to a muscle is increased beyond the threshold voltage, the amount of force produced by the whole muscle also increases

stimulus voltage

23

superficial sheath that covers the entire muscle

epimysium

24

If we place a muscle under a load than it can lift and stimulate it, what type of contraction will we produce?

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