B5 Musculoskeletal System Flashcards Preview

Phase I Medicine > B5 Musculoskeletal System > Flashcards

Flashcards in B5 Musculoskeletal System Deck (133)
Loading 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
Q

What is a reverse forward swing in terms of locomotion?

A

Moving your leg backwards for momentum but decelerating it to avoid doing the splits

26
Q

What muscles do you use to preserve the longitudinal arch of the foot during the gait cycle?

A

Intrinsic muscles of foot

Long tendons of foot

27
Q

What is another term for the loading response of the gait cycle?

A

Having a flat foot

28
Q

What muscles accept your body weight during the loading response of the gait cycle?

A

Knee extensors/Quadriceps

29
Q

What muscles decelerate your mass in the loading stage of the gait cycle?

A

Ankle plantarflexors

30
Q

What are the main ankle plantarflexors in mass deceleration of the gait cycle?

A

Triceps surae

31
Q

What muscles stabilise the pelvis in the loading phase of the gait cycle?

A

Hip abductors

32
Q

What are the main hip abductors in the gait cycle?

A

Gluteus medius

Minimus tensor of fascia lata

33
Q

What muscles are involved in control dorsiflexion of the midstance stage of the gait cycle?

A

Ankle plantarflexors

34
Q

What is the point of the control dorsiflexion stage of the midstance stage of the gait cycle?

A

To preserve momentum

35
Q

What is the last stage of the stance phase?

A

Terminal stance

36
Q

What does the terminal stance of the stance phase look like?

A

Heel coming off

37
Q

What is the first stage of the swing phase?

A

Pre-swing

38
Q

What does the first stage of the swing phase look like?

A

Toe coming off

39
Q

What muscles are used to accelerate mass in pre-swing of the swing phase?

A

Long flexors of digits

40
Q

What order does the swing phase occur in?

A

Pre-swing
Initial swing
Mid-swing
Terminal swing

41
Q

What things can alter gait?

A

Ageing
Structural damage
Artritis, inflammatory or degenerative conditions
Footware

42
Q

What order does the stance phase occur in?

A

Heel strike
Loading response
Midstance
Terminal stance

43
Q

What is antalgic gait?

A

Any gait that reduces loading on the affected extremity

44
Q

With reference to the gait cycle, how does antalgic gait reduce loading?

A

Decreasing stance phase time/ joint forces

45
Q

What are examples of antalgic gait?

A
Having a stone in your shoe
Diabetic foot
Osteoartritis
Gout
Joint/ limb deformity
Ingrown toenail
General trauma
46
Q

What is antaxic gait?

A
Unsteady, uncoordinated walk
Wide base
Feet thrown out
Can't stay steady
Similar to drunk people walking
47
Q

What diseases result in ataxic gait?

A

Multiple sclerosis

Cerebellar diseases

48
Q

What is parkinsonian gait?

A

Involuntary movement with short, accelerating steps which are often on tip toe
Trunk flexed forward
Legs flexed stiffly at the hips and knees

49
Q

What diseases cause parkinsonian gait?

A

Parkinson’s disease

Conditions affecting the basal ganglia

50
Q

What is myopathic gait more commonly known as?

A

Waddling gait

51
Q

What is myopathic gait?

A

When one leg goes into swing phase the opposite leg isn’t stable

52
Q

What group of diseases tend to cause myopathic gait?

A

Muscular diseases

53
Q

What is neuropathic gait more commonly known as?

A

High stepping gait

54
Q

What disease can you see neuropathic gait in?

A

Peripheral nerve disease

55
Q

What does neuropathic gait look like?

A

Lifting whole leg up higher than normal to avoid dragging the toe on the ground

56
Q

What muscles are weak in neuropathic gait?

A

Foot dorsiflexors

57
Q

What is a trendelenburg gait?

A

Pelvis drops when good limb enters swing phase

Pelvis not held level when walking

58
Q

What is coxa vara?

A

Decreased angle of the neck of the femoral bone

59
Q

What is coxa valga?

A

Increased angle of the neck of the femoral bone?

60
Q

What is the normal angle of the neck of the femoral bone?

A

120-140 degrees

61
Q

What causes a duck waddle gait?

A

Coxa vara

62
Q

What is pes planus?

A

Flat feet

63
Q

What are the arguments against humans being adapted for bipedalism?

A

Flat feet

Back pain

64
Q

What group of individuals are particularly prone to flat feet?

A

Overweight people who stand for long periods of time

65
Q

What signals are responsible for the form of the skeleton?

A

Genetic

Functional

66
Q

What are functional signals?

A

Signals occurring after birth to which developing bone responds

67
Q

Which embryological structures is bone derived from?

A

Neural crest

Mesoderm

68
Q

What is the process by which most bone develops?

A

Intra-membranous ossification

69
Q

What is another term for endochondral ossification?

A

Intrachondral ossification

70
Q

In bone development, which genes are responsible for specifying the identity of the different vertebral segments?

A

HOX gene

71
Q

True or false? The base of the skull develops via calcification?

A

False - The base develops from somites

72
Q

What bones develop via intra-membranous ossification?

A

Flat bones of skull
Mandible
Clavicle

73
Q

How does intra-membranous ossification work?

A

Mesenchyme cells change to osteogenic cells and then osteoblasts

74
Q

Between endochondral and intramembranous ossification, which process involves cartilage.

A

Endochondral

75
Q

How does intra-chondral ossification work?

A

Cartilage gets vascularised and dies
Calcium is deposited
Osteoblasts and osteoclasts develop

76
Q

What bones does endochrondral ossification form?

A

Most bones in the body, mainly long bones.

77
Q

Where are the genes that determine the shape and length of the fingers?

A

Progress zone

78
Q

What shape is the hand before fingers are formed?

A

Paddle-shaped

79
Q

What happens in development to form hands?

A

Cells between the fingers die

80
Q

What are the different parts of bone?

A

Epiphysis
Physis
Metaphysis
Diaphysis

81
Q

What is the another term for physis?

A

Epiphyseal (growth) plate

82
Q

What is the difference between cartilage and bone?

A

Bone is vascularised, cartilage is not.

83
Q

True or false? Bone is a connective tissue?

A

True

84
Q

What is the difference between chondroblasts and chondrocytes?

A

Chondroblasts become chondrocytes when they are surrounded by ECM

85
Q

What is the purpose of chrondroblasts in bone?

A

Cartilage formation

86
Q

What is the purpose of an extracellular matrix (ECM) in bone?

A

Fibres and ground substance production

87
Q

Give an example of a fibre found in bone?

A

Collagen

88
Q

If cartilage is avascular, how does it recieve nutrients?

A

Diffusion

89
Q

What is apositional growth?

A

The onion-like increase in size

90
Q

What are the characteristics of apositional growth?

A

Epiphyseal growth
Growth in length
Growth in diameter

91
Q

What is the difference between cancellous bone and compact bone?

A

Compact consists of densely packed osteons

Cancellous bone has a honeycomb like structure

92
Q

What are other terms for cancellous bone?

A

Trabeculae
Spongy bone
Cancellous bone

93
Q

Does bone have a more similar structure to dermal or nervous tissue?

A

Nervous

94
Q

Which bone cell is responsible for bone deposition?

A

Osteoblasts

95
Q

Which bone cell is responsible for bone resorption?

A

Osteoclasts

96
Q

Which bone cell is multi-nucleate?

A

Osteoclasts

97
Q

Which joints don’t move?

A

Synarthroses

98
Q

Which joints can move freely?

A

Diartroses

99
Q

Which joint is a well known diarthroses?

A

Synovial joint

100
Q

What is the definition of an amphiarthroses?

A

A slightly movable joint

101
Q

How does trabecular bone adapt to load?

A

Develops complementary to where load is coming from

102
Q

What are the stages of bone healing?

A
  1. Haematoma
  2. Subperiosteal & endosteal cell proliferation
  3. Callus- woven bone
  4. Consolidation
  5. Remodelling
103
Q

What bone cells are key to bone remodelling?

A

Osteoblasts

Osteoclasts

104
Q

What percentage of spongey bone is inorganic?

A

60%

105
Q

What contributes to the organic part of spongy bone?

A

Type 1 collagen

Non-collagenous proteins

106
Q

What is the difference between bone and osteoid?

A

Osteoid is unmineralised bone

107
Q

What is the cycle of bone remodelling?

A
Quiescence
Resorption
Reversal
Formation
Mineralisation
Quiescence
108
Q

How long does bone remodelling take?

A

Months

109
Q

What is the name of vitamin D’s active form?

A

1, 25 Vitamin D 3

110
Q

What does the perimysium surround?

A

Between 10-200 muscle fibres

111
Q

What does endomysium contain?

A

Myofibrils

112
Q

What does perimysium separate into?

A

Fascicles

113
Q

What are myofibrils surrounded by?

A

Sarcolemma membrane

114
Q

Where is the sarcoplasmic reticulum?

A

Around the sarcolemma membrane

115
Q

What does the I band of the sarcomere represent?

A

Actin filament

116
Q

What does the A band of the sarcomere represent?

A

Actin and myosin

117
Q

What does the H band of the sarcomere represent?

A

Myosin filaments

118
Q

What is titin?

A

A protein which anchors myosin to the Z line

119
Q

What is nebulin?

A

A protein which extends the length of actin and determines its length during assembly

120
Q

What is the difference between chimpanzee and human bipedalism?

A

Chimpanzees move bipedally using ‘bent knee bent hip’…

121
Q

What is the purpose of the iliofemoral ligament in balancing?

A

Preventing the trunk rotating backwards at the hip

122
Q

What is the purpose of the cruciate ligaments in balancing?

A

Helping keep the upper body and thigh from falling forwards at the knee

123
Q

Where do the vertebral curves pass weight to?

A

The lower limb

124
Q

What is the difference between the femur in humans and in apes?

A

The femoral head in humans is larger and its diagonal disposition makes the femur more stable.

125
Q

How is the knee joint stabilised?

A

Soft tissues; posterior and anterior cruciate ligaments and the medial and lateral collateral ligaments

126
Q

What is the ‘locking mechanism’

A

Associated with the knee enabling it to stabilise in a fully extended position

127
Q

What type of arch do primates have in their feet?

A

Transverse

128
Q

What type of arch do humans have in their feet?

A

Two-part longitudinal

129
Q

What are the parts of the longitudinal arch in the feet of humans?

A

Medial

Lateral

130
Q

Why is the arch in humans important?

A

Medial weight transfer during mid-stance; shock absorber; better weight distribution while standing.

131
Q

Where is the human body’s centre of mass?

A

Within the pelvis anterior to S2

132
Q

How is stability of a body determined?

A

The relationship between the base of support and the position of the total body centre of mass

133
Q

True or false? Bones are vascular?

A

True