Module 4: Support and Movement Flashcards

1
Q

What is a sarcomere?

A

the smallest functional unit of striated muscle tissue. It is the repeating unit between two Z-lines.

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

What are the 3 types of muscle tissue?

A

Skeletal, Smooth and Cardiac

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

T or F
Sarcomeres typically lengthen when contracting

A

F
they typically shorten

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

Skeletal muscle makes up … to
…% of body mass

A

40 to 50%

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

What creates the striped appearance of skeletal muscle?

A

The arrangement of contractile components (sarcomeres) create the striped appearance

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

Muscle attaches to bone via …. and produces movement around …

A

connective tissue (tendon)
joints

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

T or F
Skeletal muscle cells are long

A

T

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

Skeletal muscle cells are also called ….

A

muscle fibres

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

Skeletal muscle is controlled by
the … nervous system

A

somatic - can be consciously influenced

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

T or F
Each muscle fibre has multiple nuclei

A

T

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

Why do muscle cells have multiple nuclei?

A

During development, muscle fibres form by fusing multiple muscle cells

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

Name some places where smooth muscle can be found

A

The GIT, lymphatic vessels, bladder, blood vessels (e.g. artery), respiratory tract (e.g. bronchiole), skin and the iris.

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

Where is cardiac muscle found?

A

only in the contractile walls of the heart

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

Which muscle types are striated?

A

Cardiac and skeletal

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

What muscle tissue type am I?
I am striated
I branch (nonparallel)

A

Cardiac

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

What muscle tissue type am I?
I am striated
I am parallel

A

Skeletal

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

Cardiac muscle fibres
interconnect at an ….

A

intercalated disk

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

What is the purpose of an intercalated disk?

A

allows the electrical signal to pass from one muscle cell to another

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

There are approximately … different skeletal muscles in humans
x 2 sides!

A

320

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

T or F
Muscles can be easily characterized into one of gross, postural, or fine motor roles.

A

many muscles easily fit into multiple roles

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

Muscles are broadly characterised into what 3 control categories?

A

postural, fine motor and gross motor control

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

All skeletal muscles have what 4 characteristics?

A

Contractility, Excitability, Extensibility and Elasticity

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

What does muscle contractility refer to?

A

Ability to shorten and thicken, and develop tension

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

What does muscle excitability refer to?

A

Ability to respond to appropriate stimuli (action potential)

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

What does muscle elasticity refer to?

A

Ability to store some energy, and recoil to the resting length

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

What does muscle extensibility refer to?

A

Ability to be stretched without damage

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

T or F
A single muscle fibre (cell) is very long.

A

T

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

Muscle fibre is made from a large number of fused …..

A

embryonic cells

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

Inside each muscle cell is a bundle of …

A

myofibrils

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

T or F
Myofibrils lie antiparallel

A

F
They lie in parallel

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

Each myofibril contains a series of …

A

sarcomeres

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

The fascicles of muscle fibre are surrounded by ….

A

connective tissue

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

What function do sarcomeres perform?

A

The sarcomeres contain the contractile filaments that convert the
electrical signal (action potential) initiated in th

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

What is the basic contractile unit of skeletal muscle?

A

The sarcomere

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

Each sarcomere contains a series of thick
and thin … that move in relation to
each other during contraction

A

filaments

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

What causes regions of sarcomeres to appear dark under a microscope?

A

The regions that contains overlapping
thick and thin fibres look darker under
microscope, the regions which contain
only thinner fibres look lighter.

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

Thin filaments of sarcomeres are composed of …

A

actin

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

Thick filaments of sarcomeres are composed of …

A

myosin

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

(Regarding sarcomeres)
T or F
Myosin attach at the Z line
and actin anchors at the M
line in the centre of the sarcomere.

A

F
Actin attaches to the Z line and myosin anchors at the M line in the centre of the sarcomere.

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

T or F
When at rest, actin and myosin overlap

A

T

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

(Regarding sarcomeres)
Whole muscle shortening results as the filaments overlap more, pulling the … lines closer

A

Z

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

(Regarding sarcomeres)
What anchors myosin to the Z line?

A

Elastic filament: Titin

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

T or F
Titin contributes to the passive force in muscles.

A

T

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

Sarcomeres … when contracting

A

shorten

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

T or F
There is no overlap between myosin and actin in a relaxed muscle.

A

F
Some overlap of actin and myosin in relaxed muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

T or F
There is greater overlap between myosin and actin when a muscle shortens with contraction compared to a relaxed muscle

A

T

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

T or F
Myosin and Actin are thicker protein strands

A

F
They are extremely thin protein strands.

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

Which is thicker, myosin or actin?

A

Myosin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What links myosin and actin filaments together?

A

myosin heads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What property of myosin heads allows it to bind to actin filaments?

A

Myosin heads have actin binding sights

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

When talking about sarcomeres, what is a cross bridge?

A

During muscle contraction, myosin heads link the myosin and actin filaments together, forming what’s called cross bridges.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

(Regarding sarcomere cross bridges)
… pulls the … across, shortening
the muscle fibre and producing …

A

Myosin
actin
force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

T or F
Both muscle + connective tissue influence muscle function

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

… attach muscle to bone

A

Tendons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

… groups muscle fibres into a fascicle

A

Perimysium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

… groups muscle fibres into a fascicle

A

Perimysium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

A bundle of myofibrils is called a …

A

fascicle (muscle fibre)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

A bundle of sarcomeres is called a …

A

myofibril

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What is epimysium?

A

fibrous tissue that surrounds skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What is perimysium?

A

Perimysium groups muscle fibres into a fascicle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What does endomysium surround?

A

each muscle fibre (fascicle)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Muscle cells are each
innervated by a …., direct from the
spinal cord

A

motor neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What is a neuromuscular junction?

A

Where a motor axon extending from the spinal cord meets a muscle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

A single …. is the smallest
functional unit in the
musculoskeletal system.

A

motor unit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Skeletal muscle cells must get
the appropriate signal (action potential) from the …. to initiate the muscle contraction.

A

nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

When is an action potential generated?

A

When sufficient excitatory input to
reach firing threshold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

T or F
Every action potential generated in the motor neuron generates an action potential in the motor units muscle fibres.

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

T or F
Every action potential in the muscle fibres generates a little bit of force.

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

Motor units range in … and …

A

Size (number of muscle fibres)
Contractile properties (speed, fatigability)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

The … is the contractile unit of muscle

A

sarcomere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

T or F
Contraction shortens a sarcomere but does not change the length of the actin or myosin filaments.

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

When … and … are released, the myosin head bends, pulling the actin.

A

ADP
phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

When … binds to a myosin head it causes it to detach from the actin

A

ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

When … is broken down to … and …, the myosin head extends

A

ATP
ADP
Phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

Binding, power strokes, detaching and extension of myosin heads in muscle will continue as long as … are present

A

Calcium ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

T or F
The shape of the muscle will affect the action of the muscle.

A

T

77
Q

… muscles can close an opening.

A

Circular

78
Q

T or F
Short muscles are better at controlling movement over joints that have a large range of motion.

A

F
Long muscles

79
Q

A muscles …. is the greatest
predictor of force generating capacity.

A

physiological cross sectional area

80
Q

Shorter-wider muscles are better at generating larger/smaller forces, over a larger/smaller range of joint motion.

A

Larger
Smaller

81
Q

T or F
All muscles can produce similar amounts of force.

A

F
Different muscles have different abilities to produce force.

82
Q

What is the formula for a muscles physiological cross sectional area (PCSA)?

A

PCSA = Muscle volume/Fibre length

83
Q

Is muscle length or muscle fibre length more important when considering a muscles maximum force generating capacity?

A

Muscle fibre length (see PCSA eqn)

84
Q

The contractile filaments that convert the electrical signal (action potential) initiated in the nervous
system to muscle force are within the …

A

myofibril

85
Q

T or F
Sarcomere length changes during contractions and with passive stretch of a muscle.

A

T

86
Q

…. create the “active” component of muscle force generation.

A

Actin and myosin cross bridges

87
Q

Optimal sarcomere
length = …% to …% of
resting length

A

80%-120%

88
Q

T or F
Sarcomere length changes with joint position

A

T

89
Q

What is the ‘length-tension’ aka ‘force-length relationship’?

A

Describes how sarcomere length changes with joint position. Which influences the amount of force that can be developed.

90
Q

(Regarding Hill’s mechanical model of the muscle-tendon)
What part of a muscle forms the contractile component?

A

Actin and myosin cross bridges

91
Q

(Regarding Hill’s mechanical model of the muscle-tendon)
What part of a muscle forms the series elastic component?

A

titin and tendon

92
Q

(Regarding Hill’s mechanical model of the muscle-tendon)
What part of a muscle forms the parallel elastic component?

A

Connective tissue within the muscle - epimysium, perimysium and endomysium

93
Q

T or F
Connective tissue is an important
active force, limiting over stretch.

A

F
passive force

94
Q

T or F
Both active (CC) and passive (SEC and PEC) structures contribute to total force

A

T

95
Q

Motor unit = how many motoneurons?

A

1

96
Q

Are slow twitch fibres are most commonly found in power, postural or mixed muslces?

A

Slow muscle fibres are most commonly found in postural muscles, where fine control is needed >55%. Then mixed muscles 45-55% and then power muscles <45%.

97
Q

What are the 3 types of skeletal muscle fibres?

A

Slow oxidative, fast oxidative and fast glycolytic.

98
Q

Red muscle has high/low mitochondrial content whilst white muscle has high/low mitochondrial content.

A

high
low

99
Q

Oxidative fibres rely on ….

A

aerobic respiration.

100
Q

What do fast oxidative and slow oxidative muscle fibres have in common?

A

Aerobic respiration as a source of ATP, both have lots of mitochondria and both have a high myoglobin content (Red muscle).

101
Q

Myglobin is a …-… colour.

A

red-brown

102
Q

Myoglobin in an … storing protein.

A

O2

103
Q

T or F
O2 binds to haemoglobin more
than myoglobin

A

F
vice versa.

104
Q

Slow, type 1 fibres are also referred to as … because …

A

Cinderella fibres because they take longer to fatigue

105
Q

Glycolytic fibres use … for energy source.

A

glycolysis (Break down of glucose into ATP)

106
Q

Why are glycolytic fibres white?

A

Because glycolytic fibres use glycolysis for energy rather than aerobic respiration there is less O2. Less O2 means less myoglobin (which is a red-brown colour) making the muscle white.

107
Q

What is the fastest fatiguing type of skeletal muscle?

A

Fast glycolytic

108
Q

What types of skeletal muscles have a fast contraction speed?

A

Fast oxidative and fast glycolytic.

109
Q

What is Henneman’s size principle?

A

When exposed to a stimulus, small motor units (within a motor unit pool) are recruited first because they reach their threshold sooner. With greater excitatory input the number of motor units increase, and the size of the recruited motor units increase.

110
Q

Name the two dynamic muscle movements.

A

Concentric and eccentric

111
Q

Name the static muscle movement.

A

isometric

112
Q

What does isometric in reference to muscles mean?

A

There is no movement in the muscles.

113
Q

What does eccentric in reference to muscles mean?

A

The muscles are moving downwards.

114
Q

What does concentric in reference to muscles mean?

A

The muscle is moving up.

115
Q

The maximum force that can be produced is dependent on the direction such that: …> … >…
(blanks are either concentric, eccentric or isometric)

A

eccentric>isometric>concentric

116
Q

T or F
An eccentrically contracting muscle can produce more force at the same muscle length
than a concentrically contracting muscle.

A

T

117
Q

T or F
Skeletons are always comprised of bone no matter the species.

A

F

118
Q

Do humans have an endoskeleton, exoskeleton or hydrostatic skeleton?

A

Endoskeleton.

119
Q

What are the three types of skeletons?

A

endoskeleton, exoskeleton and hydrostatic skeleton.

120
Q

What are the mechanical functions of skeletons?

A

They support, protect and move.

121
Q

What are the metabolic functions of skeletons?

A

Nutrient store (minerals and
lipids), blood cell formation

122
Q

… bones make up the human
adult skeleton.

A

206

123
Q

The skeleton can be divided
into … and … bones.

A

Axial and Appendicular

124
Q

What is the difference between our axial and appendicular skeletons?

A

Axial skeleton: Relating to or situated in thehead and trunk region of the body Axial: relating to or forming an axis
Appendicular skeleton: relating to limbs Append: to add something to the end

125
Q

There are … bones in the human axial skeleton.

A

80

126
Q

What is the purpose of the skull?

A

Protects the brain. Supports soft tissues of the head. Allows movement of the jaw
during chewing.

127
Q

What is the purpose of the rib cage (including the sternum)?

A

Rib cage including sternum:
Protects heart and lungs etc.
Supports shoulder girdle and
Allows movement e.g respiration.

128
Q

What is the purpose of the vertebral column?

A

Vertebral column:
Protects the spinal cord
Supports the rib cage
Allows movement of the trunk

129
Q

There are … bones in the adult human appendicular skeleton.

A

126

130
Q

What is the sagittal anatomic plane?

A

Divides the body into left & right.

131
Q

What is the parasagittal anatomic plane?

A

Divides the left and right sides of the body in half. (Whole body in quarters)

132
Q

What is the coronal anatomic plane?

A

divides the body into dorsal & ventral or back & front, or
posterior & anterior.

133
Q

What is the transverse anatomic plane?

A

Divides the body into cranial & caudal or head & tail or superior & inferior.

134
Q

Curl your fingers into a fist. What joint movement just occurred.

A

Flexion

135
Q

What movement did Michael Jackson make when performing his anti-gravity lean?

A

Extension

136
Q

Adduction moves a body part
towards/away the midline, abduction moves it towards/away from the midline.

A

towards
away

137
Q

Adduction and Abduction movements occur in what anatomical plane?

A

the frontal plane.

138
Q

Lateral rotation refers to a joint rotating …

A

externally

139
Q

Medial rotation refers to a joint rotating …

A

internally

140
Q

Name the 3 types of joints in the skeleton.

A

Fibrous, Cartilaginous, Synovial.

141
Q

T or F
Some fibrous joints cannot move at all.

A

T
e.g. skull sutures hold the skull bones tightly in place.

142
Q

The extent a fibrous joint can move is dependent on…

A

depends on the length of the
connective tissue.

143
Q

Cartilaginous joints contain …

A

cartilage

144
Q

T or F
Cartilage tissue can move more than a fibrous joint but less than
most synovial joints.

A

T

145
Q

Cartilage serves to…

A

cushion forces.

146
Q

T or F
Synovial joints are one of the only joints that have a space (a synovial
cavity filled with fluid) between the adjoining bones.

A

F
They are the only joint with this.

147
Q

T or F
Synovial joints allow the greatest range of movement.

A

T

148
Q

… and … are important to keep bones “together” and guide motion of the joint.

A

Cartilage and ligaments

149
Q

Which one of these is NOT a joint?
Saddle joint
Synovial joint
Hinge joint
Clasp joint

A

Clasp joint

150
Q

Which one of these is NOT a joint?
Condyloid joint
Beta joint
Pivot joint
Plane joint

A

Beta joint

151
Q

T or F
Hinge joints restrict movement to a single plane.

A

T

152
Q

T or F
Opposing muscles (acting in opposing directions over a joint) are required to return the skeleton to its original place.

A

T

153
Q

Back and forth movement of a body part is accomplished by … muscle pairs applying active force to the skeleton.

A

antagonist

154
Q

During flexion the biceps … and the triceps …

A

contract
relax

155
Q

During extension the biceps … and the triceps …

A

relax
contract

156
Q

…. during childhood and adolescence is a strong determinant of peak bone mass and the eventual risk of osteoporosis.

A

Bone acquisition

157
Q

11 weeks prior to birth a foetus has … ossification centres.

A

800

158
Q

Neonates have … ossification centres.

A

450

159
Q

2/3 of a neonates skeleton is

A

cartilage

160
Q

…% of an adult skeleton is cartilage.

A

10%

161
Q

What are the 4 types of bone structure?

A

Long, short, flat and irregular

162
Q

What two types of bone structures undergo Hematopoiesis (make blood)?

A

Flat and irregular

163
Q

Square shaped bones are an example of … bones.

A

short

164
Q

T or F
High loads can modify the shape of bones.

A

F

165
Q

The protein collagen makes up …% of bones dry weight.

A

40%

166
Q

Calcium and salts make up …% of bones dry weight.

A

60%

167
Q

T or F
The collagen fibres within bone are randomly distributed in
children.

A

T

168
Q

What does collagen do for bones?

A

Provides flexibility ie fracture resistance

169
Q

What do calcium and salts do for bones?

A

Provides rigidity

170
Q

T or F
Collagen is laid down between the calcium and salt fibres of bone

A

F
vice versa.

171
Q

What are the four types of bone cells?

A

Osteoblasts, Osteocytes, Osteoclasts and Osteogenic cells.

172
Q

What bone cell type is located on the surface of a bone?

A

Osteoblasts

173
Q

Which bone cell is also a stem cell?

A

Osteogenic cells.

174
Q

Which bone cell am I?
I am a very large cell
I have many nuclei
I breakdown the bone matrix, destroy and resorb bone

A

Osteoclast

175
Q

… respond to mechanical stress
‘Dig tunnels’ to be lined with collagen by the osteoblasts

A

osteoclasts

176
Q

Which bone cell am I?
Line the tunnels with collagen. Create bone matrix, build bone (construction)

A

Osteoblasts

177
Q

Which bone cell differentiates into osteocytes when trapped in bone?

A

osteoblasts

178
Q

Which bone cell am I?
Maintain bone matrix, hold bone together.
Mineralise the bone matrix (calcium and salts)
Long cytoplasmic extensions, can supply
nutrients into the bone matrix

A

Osteocyte

179
Q

Which bone cell am I?
I develop into an osteoblast
(to form bone) and then an
osteocyte (to maintain bone)

A

osteogenic cell

180
Q

T or F
Trabecular bone (spongy bone) has a greater surface area compared to compact bone.

A

T

181
Q

T or F
Trabeculae form along lines of stress in compact bone.

A

F
In trabecular bone

182
Q

Do trabeculae or compact bone produce red blood cells and lymphocytes, and support the immune system.

A

Trabeculae

183
Q

Does trabecular or compact bone store calcium?

A

Compact bone

184
Q

Why are long bones thickest midway along the shaft?

A

because that is where bending stress is the greatest.

185
Q

T or F
A bone does not grow or remodel in response to forces applied upon it.

A

F
It does.

186
Q

How can you tell whether a human skeleton was right or left-handed?

A

Handedness (right or left handed) results in bone of one upper
limb being thicker and stronger.

187
Q

What is the most medial digit in the hand?

A

The pinkie

188
Q

… describes a position in a limb that is nearer to the trunk.

A

Proximal (e.g. in anatomical position the elbow is proximal to the wrist)

189
Q

… describes a position in a limb that is further to the trunk.

A

Distal (e.g. the wrist is distal to the elbow.