B5 Musculoskeletal System Flashcards Preview

Phase I Medicine > B5 Musculoskeletal System > Flashcards

Flashcards in B5 Musculoskeletal System Deck (133):
1

What is torque?

Force of rotational movement of bones about a joint

2

What is a muscle lever arm?

The perpendicular distance from an axis to the line of action of a force?

3

What is another term for a muscle lever arm?

Moment arm

4

What does output force require?

Long 'in' lever and a short 'out' lever

5

What does output speed require?

Short 'in' lever and a long 'out' lever

6

What are the challenges of bipedal locomotion?

Gravity and efficiency
Stability

7

Where does gravity act on the body?

The centre of mass

8

Can your centre of mass change with movement?

Yes

9

With relation to our bodies, what is gravity a product of?

Mass
Acceleration of gravity

10

Where is the human body's centre of mass?

Within the pelvis

11

What is stability of the body determined by?

Base of support
Position of total body centre of mass

12

What is gait in the simplest of words?

Pattern of interaction of limbs with the ground

13

What is gait divided into?

Stance phase
Swing phase

14

What is the definition of gait?

The period from heel strike of one limb until the next time that heel hits the ground

15

How much of the gait cycle does the stance phase take up?

First 60%

16

How much of the gait cycle does the swing phase take up?

Remaining 40%

17

What is the stance phase of the gait cycle?

Heel strike till the toe of the same foot begins to lift off the ground

18

What is the swing phase of the gait cycle?

Where the limb has lost contact with the ground

19

What is the difference between running and walking?

Walking has one foot on the ground at all times
Running you have both feet off the ground, at some point

20

When lowering the forefoot to the ground, what muscles do you use?

Ankle dorsiflexors

21

What is eccentric contraction?

The motion of an active muscle while it is lengthening under load.

22

What is concentric contraction?

The motion of an active muscle while it is shortening under load.

23

What is the main muscle responsible for ankle dorsiflexion during heel strike?

Tibialis anterior

24

What muscles are responsible for stopping your legs from swinging all the way backwards?

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