Brainscape's Knowledge GenomeTM

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


See full index

Anatomy Lecture > Chapter 9 - Muscles > Flashcards

Chapter 9 - Muscles Flashcards

0
Q

Muscular tissue accounts for _____ of total body mass

A

45%

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

The scientific study of muscles is known as ____

A

Myology

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

Does most of the work generated by the body

A

Muscles

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

Functions of muscles

A
  1. Maintain posture and body position
  2. Movement
  3. Heat production
  4. Guard orifices
  5. Support visceral organs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Four properties of muscle tissue

A
  1. Excitability
  2. Contractility
  3. Extensibility
  4. Elasticity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The ability to receive and respond to electrical or chemical stimuli

A

Excitability

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

The ability to shorten forcibly when stimulated

A

Contractility

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

The ability to be stretched forcibly when stimulated

A

Extensibility

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

Ability to return to original shape after being stretched

A

Elasticity

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

Muscles are ____

A

Organs

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

Tissue types in muscles

A
  1. Connective
  2. Arteries/Veins
  3. Nerves
  4. Lymphatics
  5. Contractile muscle cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Seven skeletal muscle characteristics

A
  1. Attaches to bone, skin, or fascia
  2. Striated with light and dark bands
  3. Voluntary control
  4. Long, thin and multi-nucleated fibers
  5. Arranged into packages that attach to and cover the bony skeleton
  6. Contracts rapidly, but tire easily
  7. May exert great force
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

One muscle cell = ?

A

One fiber

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

Main portion of a muscle

A

Belly (Gaster)

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

Muscle structure

A
  • Belly is attached to tendons

- Tendons are attached to bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q
  • Dense irregular CT around muscle

- Holds it in place and separates it from other muscles

A

Deep fascia

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

Loose CT beneathskin, surrounds several muscles

A

Subcutaneous fascia

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

Skeletal muscle organization

A
  • Many muscle fibers are bundled together into groups called fascicles
  • 10-100 muscles cells (fibers)
  • Several fascicles make up a muscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Three layers in skeletal muscle CT

A
  1. Epimysium
  2. Perimysium
  3. Endomysium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Surrounds the whole muscle

A

Epimysium

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

Surrounds fascicles

A

Perimysium

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

Separates individual muscle fibers (cells)

A

Endomysium

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

All connective tissue extends beyond the muscle belly to form the _____

A

Tendon

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

Tendons may form thick flattened sheets called

A

Aponeuroses

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

Embryonic cells that fuse to form muscle fibers

A

Myoblasts (Thats why they are so long and multinucleate)

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

Myoblasts that do not fuse become ___

A

Myosatellite cells

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

Assist in repair of damaged cells

A

Myosatellite cells

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

Three components to fiber structure

A
  1. Sarcoplasm
  2. Sarcolemma
  3. Transverse (T) tubule
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Fiber cytoplasm

A

Sarcoplasm

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

Plasma membrane of a fiber

A

Sarcolemma

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

Extensions of the sarcolemma into the sarcoplasm

A

Transverse (T) tubule

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

Contractile organelles that extend the length of fiber

A

Myofibrils

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

Myofibrils are surrounded by the ____

A

Sarcoplasmic reticulum

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

Characteristics of sarcoplasmic reticulum

A
  • Similar to ER

- Contains calcium ions

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

The functional unit of a myofibril is called a ____

A

Sarcomere

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

What are sarcomeres made of?

A

Thick and thin filaments

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

What are thick filaments made of?

A

Myosin

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

Characteristics of myosin

A
  1. Twisted protein with globular heads
  2. 1.6 um long
  3. 500/thick filament
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Two components to thin filaments

A
  1. Actin

2. Regulatory proteins

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

- Coiled “beads”

A

Actin

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

Allow and prohibit attachment between actin and myosin

A

Regulatory proteins

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

Two regulatory proteins in the thin filaments

A
  1. Tropomyosin

2. Troponin

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

Causes the striated appearance of muscle

A

Sarcomere “bands”

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

Four bands in sarcomere with their meanings

A
  1. A band - entire thick filament
  2. I band - only thin filaments
  3. H band - only thick filaments
  4. Zone of overlap - both filaments
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Divide and flank the sarcomere

A

Sarcomere “lines”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Two sarcomere lines

A
  1. Z line

2. M line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q
  • The end of the sarcomere
  • Made of actinin proteins
  • Anchor thin filaments
A

Z line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q
  • Middle of the sarcomere

- Stabilize thick filaments

A

M line

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

Three structural proteins

A
  1. Titin
  2. Nebulin
  3. Actinin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q
  • Anchors a thick filament to a Z line

- Accounts for elasticity and extensiblity

50
Q
  • Holds F actin together on thin filaments
51
Q

Makes up Z line

52
Q

As the actin slides over the myosin

A
  • Zone of overlap enlarges
  • H bands shrinks
  • I band shrinks
  • A band remains the same
  • The Z line moves closer to the A band
53
Q

Six components to neuromuscular junctions

A
  1. Motor unit
  2. Neuromuscular junction
  3. Synaptic terminal
  4. Motor end plate
  5. Synaptic cleft
  6. Neurotransmitters
54
Q

Neuron and all muscle cells stimulated by the nueron

A

Motor unit

55
Q

Point of contact between the neuron and the muscle

A

Neuromuscular junction

56
Q

End of axon that contacts motor end plate

A

Synaptic terminal

57
Q

Point on muscle fiber that contacts synaptic terminal

A

Motor end plates

58
Q

Gap between two synaptic terminals

A

Synaptic cleft

59
Q

Chemical released into that gap

A

Neurotransmitters

60
Q

When chemicals are released into the gap between the synaptic terminal

A

Acetylcholine (Ach)

61
Q

Events of muscle contraction

A
  1. Ach stored in synaptic vesicles
  2. Impulses reaches end of neuron — ach released
  3. Ach crosses gap and binds to receptors
  4. Impulse travels through motor end plate down T-tubles to SR
  5. Ca2+ ions diffuse out of SR into sarcoplasm
  6. Ca2+ exposes the active site
  7. Myosin then binds to active site
  8. ATP is used and contraction occurs
  9. Contraction continues as long as Ca2+ concentration is high
62
Q

Explain how the muscle moves due to to using ATP

A
  • The myosin head attaches to at binding site on the actin
  • ATP causes the myosin to flex and pull on the actin
  • The thin filaments slide inward
63
Q

Explain the events of muscle relaxation

A
  • Ach decomposed by acetylcholinesterase
  • Ca ions transported back to SR
  • Actin and myosin links broken
  • Cross bridges move back
  • Active site is blocked once again
64
Q

How is tension produced by a muscle determined?

A
  • The frequency of stimulation

- Number of motor units stimulated

65
Q

All fibers in a motor unit fully contract if stimulated

A

All or None Law

66
Q

Steady increase in tension by increasing the number of contracting motor unit

A

Recruitment

67
Q

Muscle never begins to relax, continuous fused contraction

68
Q

What is muscle tone?

A
  • Motor units contract randomly

- Tension, but no movement

69
Q

What can muscle tone do?

A
  • Stabilize joints
  • Holds objects in place
  • Maintain posture
70
Q

Constant, exhaustive stimulation increases the number of organelles/proteins in a fiber

A

Hypertrophy

71
Q

What does hypertrophy do?

A 
Increase:
Mitochondria 
Glycolytic enzyme reserves
Myofibrils
Filaments within myofibrils
72
Q

Do muscle fibers reproduce?

A

No you idiot, why would they?

73
Q

Overall enlargement of the muscles is do to what?

A

Hypertrophy

74
Q
  • Lack of constant motor neuron stimulation reduces organelles and proteins
  • Reversible if fiber is not dead
A 
Due to:
Age
Hormones
Lack of use
Nerve damage
75
Q

Three components to muscle attachment

A
  • Origin, insertion, force
76
Q

Attachment site that does not move

77
Q

Attachment site that moves

78
Q

Tension

79
Q

Fascicle arrangement varies based on _____

A

Position of muscles

80
Q

Fascicles parallel to long axis

- Unidirectional force

A

Parallel muscles

81
Q

Example of parallel muscles

A

Biceps brachii

82
Q

Fan shaped muscles

A

Convergent muscles

83
Q

Characteristics of convergent muscles

A
  • Multidirectional force
  • Versatility
  • Generates least amount of force
84
Q

Example of convergent muscle

A

Pectorais major

85
Q

Feather shaped muscles

A

Pennate muscles

86
Q

Characteristics of pennate muscles

A
  • Fascicles oblique to long axis
  • Tendon passes through muscle
  • Greatest force
87
Q

Example of pennate muscles

88
Q

Characteristics of circular muscles

A
  • Concentric fascicles around opening

- Contraction decreases lumen diameter

89
Q

Example of circular muscles

A

Orbicularis oculi

90
Q

Rotation around one axis

91
Q

Movements produced on a uniaxial axis

A
  • Rotation: atlantoaxial, pivot joints

- Angular: knee, IP joints

92
Q

Movements occurs along 2 axes

93
Q

Angular motions of biaxial movements

A
  • Flexion/extension
  • Abduction/adduction
    Ex: ellipsoidal joint, radiocarpal, metacarpal phalange; carpometacarpal (2-5)
94
Q

Movement on all axes

A

Multiaxial

95
Q

Angular motions of multiaxial

A
  • Same as biaxial
  • Rotation
  • Circumduction
  • Ex: ball and socket
96
Q

Main muscle causing directional force

97
Q

This can be any muscle of interest

98
Q

Muscle that contracts to oppose agonist

A

Antagonist

99
Q

Examples of antagonist pairs

A
  • Bicep brachii

- Tricep brachii

100
Q

Muscles that assists/modifies movement

101
Q

Example of synergists

A
  • Brachialis

- Pronator teres

102
Q

Muscles that stabilizes elements associated with agonist

103
Q

Example of fixator muscles

A

Deltoid stabilizes glenohumeral joint

104
Q

Lever systems modify what?

105
Q

Levers can change what?

A
  • Magnitude of force
  • Speed
  • Direction
  • Distance of limb movement
106
Q

Components of a lever system (with meanings)

A
  • Lever (L) = skeletal element
  • Effort (E) = applied force (AF)
  • Fulcrum (F) = joint
  • Resistance (R) = body part or object moved
107
Q

Explain the two characteristics of first class levers

A
  • Teeter-totter/ See-saw

- R opposite of E with central F

108
Q

Example of first class levels

A 
E = neckextensors
F = alanto-occipital joint
R = skull
109
Q

Two components to second class levers

A
  • Wheel barrow

- E opposite of F to move R

110
Q

Example of second class lever

A

Plantar extension
E = calf
F = MP joint
R = weight of body

111
Q

Characteristics of third class levers

A
  • Shovel, broom

- E in between F and R

112
Q

Example of third class levers

A

Elbow flexion
E = biceps brachii
F = elbow joint
R = weight distal to joint

113
Q

Seven characteristics of skeletal muscle fibers

A
  • Fast acting; high energy requirements
  • Anaerobic
  • Large diameter
  • Densely packed myofibrils
  • Large glycogen reserves
  • Few mitochondria
  • Rapid, powerful brief contractions
114
Q

Characteristics of slow muscle fibers

A
  • More myoglobin; slower sustained contraction
  • Aerobic
  • Smaller diameter
  • Longer to contract
  • Contract for longer time
115
Q

Characteristics of intermediate fibers

A
  • Attributes of both
  • Similar to fast fibers
  • Greater resistance to fatigue
  • Exercise (or lack of) can change one muscle type to another
116
Q

Seven characteristics of smooth muscle

A
  • Attached to hair follicles in skin
  • In walls of hollow organs and blood vessels
  • Nonstriated
  • Involuntary control
  • Contractions are slow and sustained
  • Spindle shaped
  • Very elastic
117
Q

These muscles contract slowly and are resistant to fatigue

A

Smooth muscles

118
Q

Smooth muscles are stimulated by what?

A
  • Nervous system
  • Hormones
  • Ions
  • Stretching
119
Q

Explain why smooth muscles is a single unit

A
  • Many gap junctions
  • Sheets of spindle-shaped cells
  • Contract together (syncytial contraction )
120
Q

Example of where single unit smooth muscle is

A
  • BV’s
  • Digestive tract
  • Respiratory tract
  • Urinary tract
121
Q

Example of multi-unit smooth muscles

A
  • Walls of large BV’s
  • Uterus
  • Iris of eye
122
Q

Why can smooth muscles be multi-unit?

A
  • No or few gap junctions
  • Separate fibers; contract independently
  • Only contract when stimulated by motor nerve
123
Q

Cardiac muscle characteristics

A
  • Striated in appearance
  • Involuntary control
  • Autorhythmic
  • Network of fibers with intercalated disks at ends
  • Found only in heart

Anatomy Lecture (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions