Brainscape's Knowledge GenomeTM

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


See full index

FMS > MSCT Week 2: Skeletal Muscle > Flashcards

MSCT Week 2: Skeletal Muscle Flashcards

1
Q

Types of muscle

3 Listed

A
  • skeletal muscle
  • Cardiac Muscle
  • Smooth Muscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

In all three types of muscle, energy from ____________________________ is transformed into _________________ energy.

A
  • The hydrolysis of ATP
  • Mechanical
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Skeletal muscle Cell Properties

3 Listed

A
  • elongated
  • multi-nucleated
  • grouped in bundles surrounded by connective tissue sheaths that extend from proximal origin to distal attachment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Identify

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

Epimysium description

A

is a dense connective tissue that surrounds the entire muscle and is synonymous with the deep fascia

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

Perimysium Description

2 Listed

A
  • is the connective tissue that surrounds a group of fibers to form a fascicle.
  • it conveys the large blood vessels and nerves into the muscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Endomysium Description

A

a delicate connective tissue which surrounds individual muscle fibers.

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

Identify

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

Identify fiber type

A
  • Type II fast-twitch is light colored
  • Type I slow-twitch is dark colored
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Type I muscle fibers AKA

A

Slow-Twitch

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

Type II Muscle Fibers AKA

A

Fast-Twitch

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

Type I muscle fibers are more efficient for and are primarily used for?

A

slow twitch/red muscle fibers are more efficient over long periods of time and mainly used for postural maintenance or endurance exercise.

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

Type I muscle fiber speed of contraction and innervation

A

the speed of contraction is low and there are large motor units in the muscle (large numbers of muscle fibers are innervated by a single neuron

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

Type I muscle fiber ATP generation and contents

A

ATP is generated through oxidative phosphorylation and the cells contain high levels of myoglobin

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

Type II Muscle Fibers are better for? But can?

A

better for short bursts of speed although they fatigue more quickly

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

Type II Muscle Fibers AKA

A

Fast Twitch/White

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

Type II Muscle Fibers ATP Generation and Contents

A

ATP is generated by anaerobic glycolysis and the cells contain high levels of glycogen

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

Type II Muscle Fibers Speed of Contraction

A

The speed of contraction is high

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

Type II Muscle Fibers Innervation and motor units

A

There are small motor units in the muscle and small numbers of muscle fibers are innervated by a single neuron

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

Skeletal muscle cells are formed in the embryo by

A

the fusion of myoblasts that produce a postmitotic, multinucleated myotube

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

Myotube size

A

The myotube matures into a long muscle cell with a diameter of 10 to 100um and a length of up to many centimeters

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

The individual fibers of the sartorius muscle may reach up to what in length?

A

60 cm in length

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

The plasma membrane of muscle cells is referred to as the?

A

Sarcolemma

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

The sarcolemma is surrounded by a?

A

Basal Lamina

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

The sarcolemma invaginates finger-like projections to form the?

A

Transverse Tubule System (T-Tubules)

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

T-Tubules function

A

T-Tubules make contact with the sarcoplasmic reticulum and transmit the depolarization signal deep into the muscle cell

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

What is the Sarcoplasmic reticulum?

A

an internal membrane network that has no connection with the extracellular space

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

The Sarcoplasmic Reticulum junctions with T-Tubules forms membrane structures called?

A

Triads

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

The Sarcoplasmic Reticulum function

A

The SR is a site of intracellular Ca2+ storage and release, important in the regulation of muscle contraction

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

About 80% of the cytoplasm of muscle cells is occupied by?

A

myofibrils surrounded by ATP-producing mitochondria, the SR, and T-tubules

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

Myofibrils filaments

A
  • Thin filaments containing Actin
  • Thick filaments composed of Myosin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Sarcomeres

A

the myofibrils are organized into repeating contractile elements called Sarcomeres

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

Sarcomerre unit width

A

2.2um

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

Identify

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

Sarcomere: Z-Lines

A
  • Define the boundaries of each sarcomere
  • contains the actin-binding protein alpha-actinin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Sarcomere: I-band

A
  • Composed exclusively of actin thin filaments
  • Width decreases during contraction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Sarcomere: A-band

A
  • Composed of overlapping thick and thin filaments
  • width remains constant during contraction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Sarcomere: H-Band

A
  • The central region of the A band which contains only thick filaments
  • Width decreases during contraction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Sarcomere: M-Line

A
  • Middle of the H band
  • Overlapping tails of thick filaments
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Identify

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

Thin filaments components and actions

7 listed

A
  • Thin filaments are composed of G-actin monomers that bind to each other forming a double-stranded and twisted F-actin filament
  • Each G-actin monomer displays a binding site for myosin resulting in many regularly-spaced myosin binding sites per F-actin filament
  • F-actin forms a complex with the proteins tropomyosin and the troponin complex (I, T, and C)
  • Tropomyosin consists of two polypeptides twisted around each other running in the groove formed by the F actin filaments
  • Tropomyosin binds to troponin-T of the Troponin complex
  • The other components of the troponin complex are Troponin-I which inhibits the binding of myosin to actin and troponin-C that binds Ca2+
  • Nebulin extends from the Z-line along the length of the thin filament and acts as a stabilizer of thin filament length
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Identify

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

Thick Filaments components and action

6 Listed

A
  • Thick Filaments are composed of myosin that consists of two identical heavy chains and two pairs of light chains
  • each heavy chain consists of a globular head, containing a binding site for actin and an ATPase domain, and a long α-helical coiled tail that enables several myosin molecules to self-assemble into a bipolar aggregate or filament
  • The globular head and tail are separated from one another by a movable hinge region
  • The binding and hydrolysis of ATP at the myosin head affects the interaction of myosin with actin and causes conformation changes in the protein and movement at the hinge joint
  • The myosin light chains play a role in regulating activity of the myosin head and the other protein associated with the thick filament is the molecule titin
  • Titin is a very large protein that extends from the Z-line to the center of the sarcomere and functions to control the assembly of the thick filaments and provides elasticity to the sarcomere
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Identify

A
45
Q

Skeletal muscle contracts and generates tension by?

A
  • sliding of the thick and thin filaments toward the center of the sarcomere
  • the length of the thick and thin filaments does not change during contraction
  • the length of the sarcomere decreases because the thick and thin filaments slide past one another causing the Z-lines to move closer together and the width H band and I band to decrease
46
Q

explain skeletal muscle contraction

A
47
Q

The sliding of filaments and the generation of tension is facilitated by?

A

the conformational changes in the myofibrillar proteins through the binding and hydrolysis of ATP and the release and binding of intracellular Ca2+

48
Q

Single cycle of muscle contraction

5 Listed

A
  • ATP binds to the myosin head causing the dissociation of myosin from the actin thin filament
  • ATP is hydrolyzed by the myosin head ATPase causing a conformational change in the myosin and movement at the hinge such that the angle between the head and tail increases. This lines up the head with a new myosin binding site on the thin filament
  • The myosin head attaches to the thin filament
  • The binding of myosin causes the release of Pi and a conformational change in the myosin and movement at the hinge such that the angle between the head and tail decreases. This causes a sliding of the thin filament toward the center of the sarcomere.
  • ADP is released from the myosin head and the cycle begins anew
49
Q

Describe the cross-bridge cycle

A
50
Q

Muscle Cell Depolarization

6 Listed

A
  • Depolarization spreads from the sarcolemma to the T-tubules, which transport the signal to the interior of the muscle cell
  • The depolarization of the T-Tubule is sensed by an L-type Ca2+ channels in the membrane of the T Tubule that induces the opening of ryanodine-sensitive Ca2+channels in the membrane of the sarcoplasmic reticulum
  • Calcium stored in the SR is released into the cytoplasm of the muscle fiber increasing the resting level of Ca2+ from 10-7 to 10-5 mM
  • Ca2+ binds to Troponin-C causing a conformational change in the whole troponin complex
  • The change in troponin alters the conformation of tropomyosin and leads to uncovering of the myosin-binding sites on actin allowing the thick filament head to bind to actin
  • A Ca2+ dependent ATPase mediates the return of Ca2+ into the SR during relaxation and a lowering of the cytoplasmic Ca2+ levels
51
Q

Describe muscle cell depolarization

A
52
Q

Each skeletal muscle fiber is innervated by _______________.

A

An axon of a motor neuron

53
Q

The motor neuron axon interacts with a muscle fiber via the _____________________.

A

Motor end plate or neuromuscular Junction

54
Q

Neuromuscular Junction AKA

A

Motor End Plate

55
Q

Neuromuscular junction: Contraction

5 listed

A
  • Contraction begins with the release of acetylcholine from synaptic vesicles in the motor neuron end plate
  • Acetylcholine binds to a receptor on the muscle sarcolemma and causes a depolarization of the cell membrane
  • The action potential spreads from the sarcolemma and causes a depolarization of the cell membrane
  • The action potential spreads from the sarcolemma to the T tubules, which transmits the signal to the interior of the muscle cell to cause the release of calcium from the SR
  • The activity of acetylcholine is eliminated through the action of the enzyme acetylcholinesterase that is present within the basal lamina of the synaptic cleft
56
Q

Identify

A
57
Q

Identify

A
58
Q

A Motor unit is?

A

A motor axon and all the muscle fibers that it innervates defines a “motor unit”

59
Q

Small motor units have?

A

fewer muscle cells innervated per axon (Type II)

60
Q

Large muscles have _______ motor units

A

large motor units

61
Q

Muscles requiring fine motor control have _________ motor units

A

small motor units

62
Q

fiber types of a motor unit

A

all fibers that are part of a motor unit are of the same type

63
Q

motor units and fiber type explanation

A
64
Q

Can a muscle fiber type change?

A

Yes, if the innervating neuron changes from one type to another (i.e. following an injury to the nerve) or changes the signals that it produces

65
Q

Following denervation myofibers undergo…

A

myofibers undergo atrophy, often assuming a flattened, angulated shape

66
Q

Reinnervation of myofibers

A

restores fiber size and shape but may make a denervated myofiber part of a different motor unit and a switch in fiber type

67
Q

Enlargement of motor units due to ongoing axonal or neuronal dropout or damage

A

in the face of ongoing axonal or neuronal damage and drop out, residual motor axons may innervate increasingly larger numbers of myofibers, leading to enlargement of motor units each comprised of a single type of muscle fiber (fiber type grouping) these large motor units are also susceptible to grouped atrophy if the innervating axon is damaged.

68
Q

Identify

2 Listed

A
69
Q

Sensory organs in skeletal muscle, tendons and joints

A

Proprioreceptors

70
Q

Proprioreceptors

A

provide feedback on the contractile state of the muscle, tendon tension and position of the joint

71
Q

Muscle Spindles consist of?

A
  • Found in all human skeletal muscles and consist of 2-20 intrafusal muscle fibers and their afferent nerve endings
72
Q

Muscle Spindles Function

A
  • Stretching of the muscle, and hence enclosed spindle, stimulates the nerve ending whose sensory action potential is sensed by the spinal cord
  • The appropriate motor neuron is stimulated and the stretched muscle is stimulated to contract
  • At the same time, the incoming sensory neuron synapses on an interneuron in the spinal cord that inhibits the motor neuron to the antagonistic muscle allowing it to relax
73
Q

Identify

A
74
Q

Identify

A
75
Q

The Golgi Tendon Organ function and description

2 listed

A
  • is a bare sensory nerve ending in tendons that inhibits muscle contraction when it senses excess tension placed on the tendon by a muscle
  • At the same time, it causes contraction of the antagonistic muscle group
76
Q

Identify

A

E = Epimysium

P = Perimysium

En = Endomysium

77
Q

Epimysium

A

Dense connective tissue that surrounds the entire muscle

Synonymous with deep fascia

78
Q

Perimysium is?

A

Connective tissue that surrounds a group of fibers to form a fascicle

Conveys large blood vessels and nerves to muscle

79
Q

Endomysium is?

A

Delicate connective tissue which surrounds individual muscle fibers

80
Q

Identify

A
81
Q

Type I muscle Fibers ATP is generated by?

A

Oxidative phosphorylation

82
Q

Type I muscle Fibers glycogen content

A

Low

83
Q

Type I muscle Fibers Myoglobin content

A

High

84
Q

Type I muscle Fibers Utilized for what kind of activities

A

Endurance

85
Q

Type I muscle Fibers ATPase activity and contraction speed

A

Low

86
Q

Type I muscle Fibers Resistance to fatigue

A

High

87
Q

Type I muscle Fibers motor unit size

A

Large

88
Q

Type II Muscle Fibers ATP generated by?

A

Anaerobic Glycolysis

89
Q

Type II Muscle Fibers Glycogen content

A

High

90
Q

Type II Muscle Fibers Myoglobin content

A

low

91
Q

Type II Muscle Fibers utilized for?

A

Rapid, fine movements

92
Q

Type II Muscle Fibers ATPase activity and contraction speed

A

High

93
Q

Type II Muscle Fibers Resistance to Fatigue

A

low

94
Q

Type II Muscle Fibers Motor Unit size

A

small

95
Q

What is this?

A

Sarcomere

96
Q

Identify

A
97
Q

Identify

A
98
Q

Identify

A
99
Q

Accessory proteins of myofibrils: Titan

A

Elastic protein that positions the thick filament in the sarcomere and provides elasticity to the muscle fiber

100
Q

Accessory proteins of myofibrils: Nebulin

A

Anchors the thin filament to the Z-disc

101
Q

Identify

A
102
Q

Ca2+ binds to?

A

Troponin complex

103
Q

Malignant Hyperthermia is caused by?

A

Autosomal dominant mutation in the RYR1 receptor

104
Q

Malignant Hyperthermia pathology

A
105
Q

Myasthenia Gravis is an?

A

Autoimmune Disease in which Antibodies are produced against Acetylcholine receptors

106
Q

Myasthenia gravis pathology

A
107
Q

muscle spindle overview

A
108
Q

Golgi Tendon Overview

A

FMS (34 decks)

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