Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

anatomy/physiology term 1 > muscles > Flashcards

muscles Flashcards

1
Q

what are the four general muscle functions?

A
  1. movement of bones or fluids
  2. maintaining posture and body positions
  3. stabilizing joints
  4. heat generation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the special characteristics of muscle tissue?

A

excitability, contractility, extensibility, elasticity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is excitability?

A

ability to receive and respond to stimuli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is contractility?

A

ability to shorten when stimulated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is extensibility?

A

ability to be stretched

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is elasticity?

A

ability to recoil to resting length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

muscle fiber=

A

muscle cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

my/o, mys/o, sarc/o

A

used to reference muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

sarcolemma

A

plasma membrane of muscle fiber

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

sarcoplasm

A

cytoplasm of muscle fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are the 2 myofilaments?

A

actin and myosin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

fascicles

A

a muscle made up of densely packed groups of elongated cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

muscle fibers

A

smaller units in a fascicle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

myofibrils

A

a muscle fiber made into even smaller units

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

sacromeres

A

myofibril made fo repeating units which are made up of two types of filaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are the structures of a skeletal muscle big to small?

A

muscle, fascicles, muscle fiber, myofibrils, sarcomere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

epimysium

A

dense regular connective tissue surrounding entire muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

perimysium

A

fibrous connective tissue surrounding groups of muscle fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

endomysium

A

fine loose connective tissue surrounding fascicles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

sarcoplasmic reticulum

A

surrounds myofibrils and stimulates muscle contractions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

each myofibril is made up of repeating units called _____________

A

sarcomeres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

a sarcomere is a functional unit of a ____________

A

muscle fiber

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

the sarcomere is composed of which two types of myofilaments?

A

thick and thin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

_______ is a thick filament

A

myosin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

__________ is a thin filament

A

actin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what does. myosin look like?

A

it has globular heads coming off of it, each head is attached to ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what does actin look like?

A

a twisted molecule with binding sites for myosin heads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

A band:

A

contains only actin filaments giving them a lighter appearance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Z-line:

A

anchors the actin filaments and connects myofibrils to one another, represents edges of sarcomeres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

H zone:

A

region where you find only myosin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

M line:

A

line of protein that anchors myosin filaments together during a muscle contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

how does skeletal muscle contract?

A

the movement of actin and myosin bands over eachother

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

which theory explains how a muscle contracts?

A

sliding filament theory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what does the sliding filament theory state?

A

that thin filaments slide across thick filaments, thereby shortening the sarcomere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what are the two requirements for skeletal muscle contractions?

A

activation and excitation-contracting coupling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what is activation?

A

neural stimulation at a neuromuscular junction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what is excitation-contraction coupling?

A

generation and propagation of an action potential along the sarcolemma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

what is the final trigger in excitation-contraction coupling?

A

a brief rise in intracellular calcium levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

in order for muscles to contract they have to receive a ________ from the nervous system

A

stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

the place a muscle receives a stimulus from is the ______________

A

neuromuscular junction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

skeletal muscles are stimulated by?

A

motor neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

where do axons of motor neurons travel?

A

from the central nervous system to skeletal muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

the place where an axon enters a muscle is called?

A

a motor end plate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

4 steps to activation of skeletal muscle contraction:

A
  1. nerve impulse is sent to the neuromuscular junction
  2. calcium channels open and calcium enters the axon terminal, stimulating synaptic vesicles to release the neurotransmitter acetylcholine into the synaptic cleft
  3. acetylcholine binds to receptors on the motor end plate
  4. this causes the action potential to be sent through the muscle tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

7 steps of excitation contraction coupling of skeletal muscle contraction:

A
  1. as the action potential is sent through the muscle tissue it passes through the T-tubules and into the sarcoplasmic reticulum
  2. calcium ions are released from the sarcoplasmic reticulum and invade the sarcolemma
  3. calcium ions bind to the troponin on actin and cause it to change shape
  4. tropomyosin now moves, which exposes the binding sites on the actin filaments
  5. the myosin kicks off the hydrolyzed ATP which allows the ADP to bond to actin
  6. the myosin heads pull the actin toward the m-line, shortening the sarcomere
  7. when calcium levels decrease the contraction stops and sarcomere lengthens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

how long does acetylcholine continue to stimulate action potentials?

A

until it is destroyed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

what destroys acetylcholine?

A

acetylcholinesterase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

what is acetylcholinesterase?

A

enzyme released into the synaptic cleft that destroys acetylcholine and prevents continued muscle fiber contraction

49
Q

what is a motor unit?

A

a motor neuron and all muscle fibers it innervates

50
Q

small motor units

A

found in muscles that control fine units

51
Q

what are examples of small motor units?

A

fingers and eyes

52
Q

what are large motor units?

A

found in large weight-bearing muscles

53
Q

what are examples of large motor units?

A

thighs and biceps

54
Q

motor units in a muscle usually contract _____________

A

asynchronously

55
Q

why do motor units contact asynchronously?

A

to prevent muscle fatigue

56
Q

what is a muscle twitch?

A

a motor unit’s response to a single electrical impulse sent through the motor neuron

57
Q

what does a muscle twitch cause?

A

muscle fibers to quickly contract then relax

58
Q

muscle twitches can be recorded in the lab on a _________

A

myogram

59
Q

what are the 3 phases of a twitch?

A

latent period, period of contraction, period of relaxation

60
Q

what is the latent period?

A

events of excitation-contraction coupling

61
Q

what is the period of contraction?

A

cross-bridge formation; tension increases

62
Q

what is the period of relaxation?

A

calcium re-entry into SR; tension declines to a zero

63
Q

what are graded muscle responses?

A

variations in the degree of muscle contraction

64
Q

what are graded muscle responses required for?

A

proper control of skeletal movement

65
Q

what are the 2 graded muscle responses?

A
  1. changing the frequency of a stimulation
  2. changing the strength of a stimulus
66
Q

what does a response to change in stimulus frequency do?

A

a single stimulus results in a single contractile response- a muscle twitch

67
Q

if the frequency of stimuli is ________ the muscle doesn’t have to completely relax between stimuli

A

increased

68
Q

what is a temporal (wave) summation?

A

calcium release stimulates further

69
Q

what is an infused (incomplete) tetanus?

A

a further increase in stimulus frequency

70
Q

if stimuli are given quickly enough, _________ occurs

A

fused tetany

71
Q

what is response to change in stimulus strength?

A

each muscle fiber has a threshold stimulus

72
Q

what is a threshold stimulus?

A

stimulus strength at which the first observable muscle contraction occurs

73
Q

a muscle contracts more vigorously as stimulus strength is increased above threshold due to more ________ being stimulated

A

motor units

74
Q

what is contraction force and what does it do?

A

it is precisely controlled by the recruitment of motor units, which brings more muscle fibers into action

75
Q

what is size principle?

A

motor units with larger and larger fibers that are recruited as stimulus intensity increases

76
Q

the constant state of slight contraction is called what?

A

muscle tone

77
Q

isotonic

A

muscle contracts and shortens

78
Q

what is an example of isotonic?

A

occurs when we walk or lift objects

79
Q

isometric

A

tension increases but muscle doesn’t shorten

80
Q

what is an example of isometric?

A

tensing the abdominal muscles

81
Q

our ___________ can change in size depending on our level of activity

A

muscle fibers

82
Q

atrophy

A

the shrinking of muscles from not using them

83
Q

hypertrophy

A

enlarged muscles due to overuse or over-excercise

84
Q

when muscles get bigger they increase in size, and there is/is not an increase in the number of muscle cells

A

is not

85
Q

___ is the only source of energy used to power muscle contractions

A

ATP

86
Q

how fast are available stores of ATP depleted?

A

4-6 seconds

87
Q

what are the 3 ways ATP is regenerated by?

A
  1. direct phosphorylation by creating phosphate
  2. anaerobic pathway
  3. aerobic respiration
88
Q

anaerobic pathway is at __% of maximum contractile activity

A

70

89
Q

what compresses blood vessels?

A

bulging muscles

90
Q

in an anaerobic pathway oxygen delivery is __________

A

impaired

91
Q

in anaerobic pathway which acid is converted into lactic acid?

A

pyruvic acid

92
Q

what are 3 traits of lactic acid?

A
  1. diffuses into the bloodstream
  2. used as a fuel by the liver, kidneys, and heart
  3. converted back into pyruvic acid by the liver
93
Q

aerobic pathway produces __% of ATP during rest and light to moderate excercise

A

95%

94
Q

what are some fuels of aerobic pathway?

A
  1. stored glycogen
  2. blood borne glucose
  3. pyruvic acid from glycolysis
  4. free fatty acids
95
Q

what is muscle fatigue?

A

physiological inability to contract due to overuse of the muscle

96
Q

what is muscle fatigue caused by?

A

oxygen reserves, glycogen stores, ATP and CP reserves, conversion of lactic acid back to pyruvic acid

97
Q

what are some effects of training on muscle efficiency?

A
  • improved motor unit/ muscle coordination
  • improved functioning of the respiratory and circulatory system
  • elimination or reduction of excess fat
  • improved joint movement
98
Q

what are some effects of training on muscle strength?

A
  • increase in muscle size
  • improved muscle coordination
  • improved functioning in the cortical brain region
99
Q

muscles only ______

A

pull

100
Q

what attaches muscles to bones?

A

tendons

101
Q

what is the part of the skeletal muscle attached to a fixed bone?

A

orgin

102
Q

what part of a muscle does not move during a muscle contraction?

A

the orgin

103
Q

what part of a muscle is attached to a moveable part?

A

insertion

104
Q

what part of the muscle moves during muscle contraction?

A

insertion

105
Q

the ______ produces movement in a singe direction

A

prime mover

106
Q

the muscle being contracted is an example of which pair?

A

prime mover

107
Q

the ______ moves bone in opposite direction

A

antagonist

108
Q

what is an example of an antagonist?

A

muscle that relaxes

109
Q

_________ help to steady a movement or stabilize joint activity

A

synergists

110
Q

how are muscles named by location?

A

some names indicate the bone that the muscle is attached to

111
Q

how are muscles named by shape?

A

some refer to the shape of the muscle

112
Q

how are muscles named by size?

A

some refer to maximus and minimus

113
Q

______ muscles have muscle fibers that run parallel to the midline

A

rectus

114
Q

_____ muscles have muscle fibers that run perpendicular to the midline

A

transverse

115
Q

______ muscles have muscle fibers that run diagonally

A

oblique

116
Q

how are skeletal muscles name by number of orgin?

A

biceps vs triceps vs quadriceps

117
Q

how are muscles named according to the point of attachments?

A

named according to point of origin and insertion

118
Q

how are muscles named due to muscle action?

A

named for the type of movement they produce

anatomy/physiology term 1 (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions