B5 Musculoskeletal System Flashcards
1
Q
What is torque?
A
Force of rotational movement of bones about a joint
2
Q
What is a muscle lever arm?
A
The perpendicular distance from an axis to the line of action of a force?
3
Q
What is another term for a muscle lever arm?
A
Moment arm
4
Q
What does output force require?
A
Long ‘in’ lever and a short ‘out’ lever
5
Q
What does output speed require?
A
Short ‘in’ lever and a long ‘out’ lever
6
Q
What are the challenges of bipedal locomotion?
A
Gravity and efficiency
Stability
7
Q
Where does gravity act on the body?
A
The centre of mass
8
Q
Can your centre of mass change with movement?
A
Yes
9
Q
With relation to our bodies, what is gravity a product of?
A
Mass
Acceleration of gravity
10
Q
Where is the human body’s centre of mass?
A
Within the pelvis
11
Q
What is stability of the body determined by?
A
Base of support
Position of total body centre of mass
12
Q
What is gait in the simplest of words?
A
Pattern of interaction of limbs with the ground
13
Q
What is gait divided into?
A
Stance phase
Swing phase
14
Q
What is the definition of gait?
A
The period from heel strike of one limb until the next time that heel hits the ground
15
Q
How much of the gait cycle does the stance phase take up?
A
First 60%
16
Q
How much of the gait cycle does the swing phase take up?
A
Remaining 40%
17
Q
What is the stance phase of the gait cycle?
A
Heel strike till the toe of the same foot begins to lift off the ground
18
Q
What is the swing phase of the gait cycle?
A
Where the limb has lost contact with the ground
19
Q
What is the difference between running and walking?
A
Walking has one foot on the ground at all times
Running you have both feet off the ground, at some point
20
Q
When lowering the forefoot to the ground, what muscles do you use?
A
Ankle dorsiflexors
21
Q
What is eccentric contraction?
A
The motion of an active muscle while it is lengthening under load.
22
Q
What is concentric contraction?
A
The motion of an active muscle while it is shortening under load.
23
Q
What is the main muscle responsible for ankle dorsiflexion during heel strike?
A
Tibialis anterior
24
Q
What muscles are responsible for stopping your legs from swinging all the way backwards?
A
Hip extensors
25
What is a reverse forward swing in terms of locomotion?
Moving your leg backwards for momentum but decelerating it to avoid doing the splits
26
What muscles do you use to preserve the longitudinal arch of the foot during the gait cycle?
Intrinsic muscles of foot
| Long tendons of foot
27
What is another term for the loading response of the gait cycle?
Having a flat foot
28
What muscles accept your body weight during the loading response of the gait cycle?
Knee extensors/Quadriceps
29
What muscles decelerate your mass in the loading stage of the gait cycle?
Ankle plantarflexors
30
What are the main ankle plantarflexors in mass deceleration of the gait cycle?
Triceps surae
31
What muscles stabilise the pelvis in the loading phase of the gait cycle?
Hip abductors
32
What are the main hip abductors in the gait cycle?
Gluteus medius
| Minimus tensor of fascia lata
33
What muscles are involved in control dorsiflexion of the midstance stage of the gait cycle?
Ankle plantarflexors
34
What is the point of the control dorsiflexion stage of the midstance stage of the gait cycle?
To preserve momentum
35
What is the last stage of the stance phase?
Terminal stance
36
What does the terminal stance of the stance phase look like?
Heel coming off
37
What is the first stage of the swing phase?
Pre-swing
38
What does the first stage of the swing phase look like?
Toe coming off
39
What muscles are used to accelerate mass in pre-swing of the swing phase?
Long flexors of digits
40
What order does the swing phase occur in?
Pre-swing
Initial swing
Mid-swing
Terminal swing
41
What things can alter gait?
Ageing
Structural damage
Artritis, inflammatory or degenerative conditions
Footware
42
What order does the stance phase occur in?
Heel strike
Loading response
Midstance
Terminal stance
43
What is antalgic gait?
Any gait that reduces loading on the affected extremity
44
With reference to the gait cycle, how does antalgic gait reduce loading?
Decreasing stance phase time/ joint forces
45
What are examples of antalgic gait?
```
Having a stone in your shoe
Diabetic foot
Osteoartritis
Gout
Joint/ limb deformity
Ingrown toenail
General trauma
```
46
What is antaxic gait?
```
Unsteady, uncoordinated walk
Wide base
Feet thrown out
Can't stay steady
Similar to drunk people walking
```
47
What diseases result in ataxic gait?
Multiple sclerosis
| Cerebellar diseases
48
What is parkinsonian gait?
Involuntary movement with short, accelerating steps which are often on tip toe
Trunk flexed forward
Legs flexed stiffly at the hips and knees
49
What diseases cause parkinsonian gait?
Parkinson's disease
| Conditions affecting the basal ganglia
50
What is myopathic gait more commonly known as?
Waddling gait
51
What is myopathic gait?
When one leg goes into swing phase the opposite leg isn't stable
52
What group of diseases tend to cause myopathic gait?
Muscular diseases
53
What is neuropathic gait more commonly known as?
High stepping gait
54
What disease can you see neuropathic gait in?
Peripheral nerve disease
55
What does neuropathic gait look like?
Lifting whole leg up higher than normal to avoid dragging the toe on the ground
56
What muscles are weak in neuropathic gait?
Foot dorsiflexors
57
What is a trendelenburg gait?
Pelvis drops when good limb enters swing phase
| Pelvis not held level when walking
58
What is coxa vara?
Decreased angle of the neck of the femoral bone
59
What is coxa valga?
Increased angle of the neck of the femoral bone?
60
What is the normal angle of the neck of the femoral bone?
120-140 degrees
61
What causes a duck waddle gait?
Coxa vara
62
What is pes planus?
Flat feet
63
What are the arguments against humans being adapted for bipedalism?
Flat feet
| Back pain
64
What group of individuals are particularly prone to flat feet?
Overweight people who stand for long periods of time
65
What signals are responsible for the form of the skeleton?
Genetic
| Functional
66
What are functional signals?
Signals occurring after birth to which developing bone responds
67
Which embryological structures is bone derived from?
Neural crest
| Mesoderm
68
What is the process by which most bone develops?
Intra-membranous ossification
69
What is another term for endochondral ossification?
Intrachondral ossification
70
In bone development, which genes are responsible for specifying the identity of the different vertebral segments?
HOX gene
71
True or false? The base of the skull develops via calcification?
False - The base develops from somites
72
What bones develop via intra-membranous ossification?
Flat bones of skull
Mandible
Clavicle
73
How does intra-membranous ossification work?
Mesenchyme cells change to osteogenic cells and then osteoblasts
74
Between endochondral and intramembranous ossification, which process involves cartilage.
Endochondral
75
How does intra-chondral ossification work?
Cartilage gets vascularised and dies
Calcium is deposited
Osteoblasts and osteoclasts develop
76
What bones does endochrondral ossification form?
Most bones in the body, mainly long bones.
77
Where are the genes that determine the shape and length of the fingers?
Progress zone
78
What shape is the hand before fingers are formed?
Paddle-shaped
79
What happens in development to form hands?
Cells between the fingers die
80
What are the different parts of bone?
Epiphysis
Physis
Metaphysis
Diaphysis
81
What is the another term for physis?
Epiphyseal (growth) plate
82
What is the difference between cartilage and bone?
Bone is vascularised, cartilage is not.
83
True or false? Bone is a connective tissue?
True
84
What is the difference between chondroblasts and chondrocytes?
Chondroblasts become chondrocytes when they are surrounded by ECM
85
What is the purpose of chrondroblasts in bone?
Cartilage formation
86
What is the purpose of an extracellular matrix (ECM) in bone?
Fibres and ground substance production
87
Give an example of a fibre found in bone?
Collagen
88
If cartilage is avascular, how does it recieve nutrients?
Diffusion
89
What is apositional growth?
The onion-like increase in size
90
What are the characteristics of apositional growth?
Epiphyseal growth
Growth in length
Growth in diameter
91
What is the difference between cancellous bone and compact bone?
Compact consists of densely packed osteons
| Cancellous bone has a honeycomb like structure
92
What are other terms for cancellous bone?
Trabeculae
Spongy bone
Cancellous bone
93
Does bone have a more similar structure to dermal or nervous tissue?
Nervous
94
Which bone cell is responsible for bone deposition?
Osteoblasts
95
Which bone cell is responsible for bone resorption?
Osteoclasts
96
Which bone cell is multi-nucleate?
Osteoclasts
97
Which joints don't move?
Synarthroses
98
Which joints can move freely?
Diartroses
99
Which joint is a well known diarthroses?
Synovial joint
100
What is the definition of an amphiarthroses?
A slightly movable joint
101
How does trabecular bone adapt to load?
Develops complementary to where load is coming from
102
What are the stages of bone healing?
1. Haematoma
2. Subperiosteal & endosteal cell proliferation
3. Callus- woven bone
4. Consolidation
5. Remodelling
103
What bone cells are key to bone remodelling?
Osteoblasts
| Osteoclasts
104
What percentage of spongey bone is inorganic?
60%
105
What contributes to the organic part of spongy bone?
Type 1 collagen
| Non-collagenous proteins
106
What is the difference between bone and osteoid?
Osteoid is unmineralised bone
107
What is the cycle of bone remodelling?
```
Quiescence
Resorption
Reversal
Formation
Mineralisation
Quiescence
```
108
How long does bone remodelling take?
Months
109
What is the name of vitamin D's active form?
1, 25 Vitamin D 3
110
What does the perimysium surround?
Between 10-200 muscle fibres
111
What does endomysium contain?
Myofibrils
112
What does perimysium separate into?
Fascicles
113
What are myofibrils surrounded by?
Sarcolemma membrane
114
Where is the sarcoplasmic reticulum?
Around the sarcolemma membrane
115
What does the I band of the sarcomere represent?
Actin filament
116
What does the A band of the sarcomere represent?
Actin and myosin
117
What does the H band of the sarcomere represent?
Myosin filaments
118
What is titin?
A protein which anchors myosin to the Z line
119
What is nebulin?
A protein which extends the length of actin and determines its length during assembly
120
What is the difference between chimpanzee and human bipedalism?
Chimpanzees move bipedally using 'bent knee bent hip'...
121
What is the purpose of the iliofemoral ligament in balancing?
Preventing the trunk rotating backwards at the hip
122
What is the purpose of the cruciate ligaments in balancing?
Helping keep the upper body and thigh from falling forwards at the knee
123
Where do the vertebral curves pass weight to?
The lower limb
124
What is the difference between the femur in humans and in apes?
The femoral head in humans is larger and its diagonal disposition makes the femur more stable.
125
How is the knee joint stabilised?
Soft tissues; posterior and anterior cruciate ligaments and the medial and lateral collateral ligaments
126
What is the 'locking mechanism'
Associated with the knee enabling it to stabilise in a fully extended position
127
What type of arch do primates have in their feet?
Transverse
128
What type of arch do humans have in their feet?
Two-part longitudinal
129
What are the parts of the longitudinal arch in the feet of humans?
Medial
| Lateral
130
Why is the arch in humans important?
Medial weight transfer during mid-stance; shock absorber; better weight distribution while standing.
131
Where is the human body's centre of mass?
Within the pelvis anterior to S2
132
How is stability of a body determined?
The relationship between the base of support and the position of the total body centre of mass
133
True or false? Bones are vascular?
True
