The Musculoskeletal System Flashcards Preview

631: Clinical Management of the Musculoskeletal System I > The Musculoskeletal System > Flashcards

Flashcards in The Musculoskeletal System Deck (97):
1

What are the 4 types of fundamental tissues?

- Epithelial
- Connective
- Muscle
- Nervous

2

Connective tissue is composed of what 2 substances?

- ground substance
- fibroblasts

3

What 3 things do fibroblasts produce?

- collagen
- elastin
- reticulin fibers

4

2 types of collagen

loose or dense

5

Where can loose collagen be found?

In capsules, muscles, nerves, fascia, and skin

6

What is the main function of loose collagen?

Provides structural support

7

Where can dense collagen be found?

Ligaments, tendons, bones, and aponeuroses

8

What is the function of fascia?

It provides an interconnection between tendons, ligaments, capsules, nerves and the intrinsic components of muscle

9

What is the function of tendons?

To attach muscle to bone at each end of the muscle, and, when stretched, store elastic energy that contributes to movement

10

What are the 3 main sections of a tendon?

- Bone-tendon junction
- Tendon mid-substance
- Musculotendinous Junction (MTJ)

11

The point where the collagen fibers of the tendon directly insert into the bone is called what?

Enthesis

12

What is the role of the enthesis?

To absorb and distribute the stress concentration that occurs at the junction over a broader area

13

What type of injuries are likely to occur at the tendon's midsubstance?

oversue injuries

14

What type of injuries are likely to occur at the tendon's MTJ?

tensile failure (sudden)

15

What do ligaments do?

attach bone to bone

16

How do ligaments contribute to the stability of function?

By preventing excessive motion, guide the direction of movement, provide proprioceptive feedback, and act as the attach point to the joint capsule

17

What parts of ligaments are the most avascular and have minimal innervation?

The middle sections

18

Do tendons or ligaments deform less under an applied load and are able to transmit the load to bone?

Tendons

19

Do tendons or ligaments have a more unidirectional line of pull?

tendons

Ligaments still provide stiffness however

20

3 forms of cartilage

- hyaline
- elastic
- fibrocartilage

21

Where can hyaline (articular) cartilage be found?

covering bones which provides an almost frictionless motion between joint surfaces

22

What 3 things is hyaline cartilage composed of?

- chondrocytes
- water
- ECM

23

Does hyaline cartilage have blood vessels, lymphatics, and nerves?

NO

24

What are the 4 zones of articular cartilage?

1) Superficial zone
2) Middle zone
3) Deep zone
4) Tidemark zone

25

What is the function of the superficial zone of articular cartilage?

to protect the deeper layers from sheer stress

26

What is the function of the middle zone of articular cartilage?

provides an anatomic and functional bridge between the superficial and deep zones

27

How are collagen fibers oriented in the middle zone?

obliquely

28

What is the function of the deep zone of articular cartilage?

Provides the greatest resistance to compressive forces

29

How are collagen fibers oriented in the deep zone?

radially

30

What is the function of the tidemark zone of articular cartilage?

prevents diffusion of nutrients from the bone tissue to the cartilage

31

Where can elastic cartilage be found?

the outer ear, larynx, etc.

32

What is the function of fibrocartilage?

A shock-absorber in both weight-bearing and non-weight-bearing joints

33

fibrocartilage's large fiber content, reinforced with numerous collagen fibers, makes it ideal for what?

Bearing large stress in all directions

34

What are a few examples of fibrocartilage?

The pubic symphysis, IVDs, and the menisci of the knee

35

5 functions of bone

- provide support
- enhance leverage
- protect vital structures
- provide attachments for both tendons & ligaments
- store minerals

36

What are the 4 characteristics of skeletal muscle?

- Excitability
- Elasticity
- Extensibility
- Contractility

37

Excitability is the ability to do what?

respond to stimulation from the nervous system

38

Elasticity is the ability to do what?

change in length or stretch and return to normal length afterwards

39

Extensibility is the ability to do what?

shorten and return to normal length

40

Contractility is the ability to do what?

shorten and contract in response to some neural command

41

The tension developed in in skeletal muscle can occur _____ (stretch) or ____ (contraction)

passively

actively

42

A single muscle cell is called what?

a myofiber

43

Describe the 3 coverings of myofibers

A single myofiber is wrapped in endomysium.
Bundles of myofibers are wrapped in perimysium
Bundles of myofibrils are wrapped in epimysium

44

Each myofiber consists of thousands of fibers called ______ which run parallel to the myofibril axis.

myofilaments

45

Myofilaments are composed of what 2 proteins?

actin and myosin

46

Structures called ______ serve to connect the actin and myosin filaments

cross-bridges

47

During contraction the cross-bridges _____.
During relaxation the cross-bridges _____.

attach

detach

48

What 2 proteins found in the actin filaments regulate the attachment and detachment of the cross-bridges?

tropomyosin and troponin

49

Each muscle fiber is innervated by what type of neuron?

a somatic motor neuron

50

What constitutes a motor unit?

One neuron and its corresponding muscle fibers

51

What are the 2 major types of muscle fiber?

- Type I (slow twitch)
- Type II (fast twitch)

52

Which type of muscle fiber is the first to be recruited?

Type I

53

Define prime agonist

the muscle that is directly responsible for producing movement

54

Define synergist

the muscle that performs cooperative muscle function with regard to agonist

55

Define stabilizer

The muscle that contracts statically to steady or support some part of the body

56

Define neutralizers

muscles that act to prevent an undesired action

57

Define antagonists

muscles that have effect opposite of the agonist

58

3 types of contractions

- Isometric
- Concentric
- Eccentric

59

As the speed of a concentric contraction increases, the force produced _____.

decreases

60

As the speed of a eccentric contraction increases, the force produced _____.

increases

61

A slow eccentric contraction is similar to what type of contraction?

an isometric contraction

62

Under what 2 circumstances does a muscle generate the greatest amount of torque?

- When the line of pull is oriented at a 90 degree angle to the bone
- When it is attached anatomically as far from the joint center as possible

63

Skeletal muscle blood flow increases __-fold during muscle contraction

20

64

4 differences between respiratory and skeletal muscle

- Skeletal muscle overcomes inertial loads, whereas respiratory muscles overcome elastic and resistive loads
- they are under voluntary and involuntary control
- they have to contract rhythmically and generate the required forces for ventilation throughout the entire life of an individual
- They are constrained to operate at a particular resting length

65

2 Joint classifications based on movement

Synarthrosis (little to no movement) or Diarthrosis (free bone movement and great mobility)

66

2 major types of synarthroses

- Fibrous joints
- Cartilaginous joints

67

3 types of fibrous joints and an example for each

- suture --> skull
- gomphosis --> tooth/mandible
- syndesmosis --> tibfib/radioulnar

68

2 types of cartilaginous joints and an example for each

- Synchondrosis --> manubriosternal
Symphysis --> symphysis pubis

69

6 characteristics of diathroses

- joint cavity
- articular cartilage
- synovial fluid
- synovial membrane
- fibroelastic capsule
- mechanoreceptors and nociceptors

70

Example of a spheroid joint

shoulder (ball and socket)

71

Example of a trochoid joint

atlantoaxial joint (pivot)

72

Example of a condyloid joint

wrist

73

Example of a ginglymoid joint

humeroulnar (hinge)

74

Example of an ellipsoid joint

radiocarpal

75

Example of a planar joint

intermetatarsal

76

Example of a sellar joint

thumb (saddle)

77

What type of fluid is necessary to minimize the frictional resistance between weight-bearing surfaces in joints?

synovial fluid

78

What are bursae?

Flattened, saclike structures that are lined with synovial membrane and filled with synovial fluid, which allows for smooth motion between muscles, tendon, ligament, and bones

79

What are the 2 types of movement?

- translation which occurs in either a straight or curved line
- rotation which involves a circular motion around a pivot point

80

A joint that can swing in one direction or can only spin is said to have ___ DOF

one

81

A joint that can swing and spin in one way or can swing in two completely distinct ways, but not spin is said to have ___ DOF

two

82

A joint that can spin and also swing in two distinct ways is said to have ___ DOF

three

83

What is kinematics?

They study of motion

84

What is kinetics?

The term applied to the forces acting on the body

85

3 types of arthrokinematics

roll, slide, and spin

86

Convex surface moving on concave surface, then the slide will be in the _____ direction to the osteokinematic motion

opposite

87

Concave surface moving on convex surface, then the slide will be in the _____ direction to the osteokinematic motion

same

88

What are levers?

rotations of a rigid surface around an axis

89

When does a first-class lever occur?

When two forces are applied on either side of an exis and the fulcrum lies between the effort and the load (like a seesaw)

90

Examples of a first-class lever

contraction of the triceps at the elbow o tipping the head forwards and backwards

91

When does a second-class lever occur?

When the load (resistance) is applied between the fulcrum and the point where the effort is exerted

92

Example of a second-class lever

Weight bearing plantarflexion

93

When does a third-class lever occur?

When the load is located at the end of the load (like a drawbridge or crane)

94

Example of a third-class lever

Elbow flexion

95

Most movable joints function as what type of lever?

third-class

96

In a closed kinematic chain the ____ segment is stabilized and the movement is at the _____ segment

distal

proximal

97

In an open kinematic chain the ____ segment is stabilized and the movement is at the _____ segment

proximal

distal