Exam 1 Flashcards
(83 cards)
1
Q
fibroblasts
A
- in tendon, ligament, skin, bone
- creates mostly type I collagen
2
Q
chondroblasts
A
- in cartilage
- produces mostly type II
3
Q
Osteoblasts
A
- found in bone
- produces type I collagen and
4
Q
what forms periarticular connective tissues:
A
- fibrous proteins: collagen, elastin
- ground substance: glycosaminoglycans (GAG), water, solutes
- cells: fibroblasts, chondrocytes
5
Q
difference between collagen and elastin?
A
Collagen triple helix
Elastin: net like, no helix, has more give than collagen
6
Q
Type I collagen
A
- thick fibers that elongate little when stretched
- comprise ligaments, tendons, fascia, fibrous joint capsules
7
Q
Type II collagen
A
- thinner fibers
- framework for maintaining general shape and consistency of structures
- hyaline cartilage
8
Q
dense connective tissues
A
- abundant type I collagen
- limited blood supply
- low PG’s/Elastin/cells so low metabolism
9
Q
acute trauma happens mostly to which joints?
A
-joints with longest bones since they form longest external moment arms
10
Q
chronic trauma
A
- overuse, damage over time
- instability = abnormal loading
- loss of proteins, GAG, water
11
Q
joint pathology from aging
A
- protein/PG replacement slows
- dissicated ligaments/cartilage don’t slide as well
- tendons become less stiff and can’t produce muscle force
- weaker bones (reduced cell differentiation
12
Q
How to regenerate tendon/ligament
A
-cell: fibroblast
-Stimulus: tension along lines of stress
EX: ext knee for MCL
13
Q
how to regenerate cartilage
A
cell: chondrocyte
Stimulus: load/unload along with gliding
EX:bike for patellofemoral irriation
14
Q
how to regenerate muscle
A
cell: myocyte
Stimulus: tension to cause disruption of myofibrils
EX: take it to the point of microtearing
15
Q
how to regenerate bone
A
cell: osteocyte
Stimulus: compression or tension
EX: with rod through bone for fracture, walk on it; compression stimulates new bone matrix
16
Q
enthesis organ
A
- reduces tensile load on insertion
- confers a mechanical advantage on muscle-tendon unit
- different tissues with different Youn’s moduli gliding along each other cause inappropriate cell stimulation
17
Q
mechanotransduction
A
: how mechanical forces cause protein expression
18
Q
bone has what type of collagen?
A
type I
19
Q
cartilage has what type of collagen?
A
type II
20
Q
tissue type of joint capsules
A
- dense irregular
- stretched in all directions so striations not in same direction
21
Q
tissue type of tendon/ligament
A
dense regular
-striate in uniform direction
22
Q
loose connective tissue
A
does not have as much collagen
23
Q
collagen is a ___
A
protein
24
Q
Scleraxis Protein
A
- leads to new tendon building blocks
- turned on by amount of load (in its line of stress)
- imperfect restoration
25
Tissue make up effected by:
- activity
- inactivity
- age
- trauma
26
example of a planar joint
- facet joints in vertebral columm
| - carpals (hamate and triquetrum)
27
example of a hinge joint
humeroulnar joint at elbow
28
example of pivot joint
atlas on dens of axis
29
example of a saddle joint
thumb carpal to metacarpal joint
30
example of a condyloid joint
carpal MCP joint
31
diarthrodial joints
- synovial joints
- freely moveable
- joint cavity separates bones
32
Layers of synovial joint (superficial to deep)
1. ligament
2. joint capsule
3. fat pad
4. synovial membrane
5. articular cartilage
6. synovial fluid
33
location of nerves in a synovial joint:
- bone
- articular cartilage
- in outer layer of joint capsule
34
thickness of articular cartilage
1-7 mm
| -thicker at weight bearing joints; thickest at the hip
35
articular cartilage
- to disperse loads
- doesn't have pericondrium so it is harder to heal
- avascular and aneural (may have some sensory nerves but mostly no pain until cartilage breaks down)
36
difference of cells in the superficial zone of articular cartilage?
- more cells (chondrocytes)
- smaller
- closer together
37
tide mark in articular cartilage
on top of the calcified zone
| -
38
nutrition above and below the tidemark
above: synovial fluid
below: vascular supply
39
what is the first line of defense against loads
articular cartilage
40
articular carilage extracellular matrix
- fibrillar (protein: collagen (70% of dry weight), elastin)
| - interfibrillar (ground substance: PGs)
41
GAG is mechanism for maintaining articular cartilage__
hydration
| -water attaches to it
42
___ is better at resisting shearing
collagen
43
more water then ____ premeability
greater
| -the less it will resist the compressive force
44
as GAG contact increases then...
creep stiffness increases
45
stiffness in shear is directly proportional to__
amount of collagen
46
relationship of the axis and plane of motion
axis is perpendicular to the plane of motion
47
close packed
- good congruency
- taut ligaments
- increased stability
- little accessory motion
48
loose packed
- decreased congruency
- loose ligaments
- max accessory motion
49
position you do mobilizations
loose packed
50
joint position you test in
loose packed
51
creep is a phenomenon of_____
viscoelasticity
52
slope of the stress/strain curve =
stiffness
53
young's modulus
: measure of stiffness of a solid material
54
toe region is caused by
the uncrimping of collagen
55
the solid phase of articular cartilage resists...
tension
56
optimal stimulus for articular cartilage
load/unload with gliding
57
an osteoarthritic joint is ____ stiff
less
58
creep
- constant load (stress)
- deformation over time (strain)
- may not be permanent
59
stress relaxation
- constant position (strain)
| - change in stress over time
60
moment arm
perpendicular distance from axis to line of pull of force
61
moment arm is 0 if:
1. the force pierces the axis
| 2. the force parallels the axis
62
first class lever
EF
Axis
IF
-neck extensors
63
second class lever system
```
axis
EF
IF
-gastrocnemius
-less muscle force required
-less motion of the bone
-less speed
```
64
third class
```
axis
IF
EF
-bicep brachii
-greater muscle force required
-more motion at distal end of bone
-higher speed
```
65
mechanical advantage of 2nd class lever systems
greater than 1
66
mechanical advantage of 3rd class lever systems
less than one
67
synarthroses
reinforced by fibrous and cartilaginous connective tissues
| -permit slight to no movement
68
diarthroses
- possess a synovial fluid-filled cavity
| - permit moderate to extensive movement
69
joint capsule
- external fibrous layer
- nerve endings
- internal/synovial membrane
70
cell membrane
-secretes fluid
71
capsule external layer
- attaches to periosteum, then bone via sharpey's fibers
- richly innervated
- joint receptors
72
ligaments
-thickening of capsule or separate (extra-capsular)
73
internal joint capsule
-synovial membrane
| 3-10 cell layers thick
74
differentiation of connective tissue comes from
mesenchymal cells
75
connective tissue
- large varience
| - dependent on function
76
dense connective tissue
- few cells
- low proteoglycans and elastin
- type I collagen
- limited blood supply
77
purpose of carbohydrates in GAG
to attract water
78
what happens to collagen leaves with degeneration?
they start to separate
79
purpose of type II collagen
provide a framework for maintaining shape and consistency of the structure
80
phase 1 protects against
compression by water leaving
81
phase 2 protects against
tension by collagen
82
hoop stresses
- tension forces generated from compressive forces
| - hoop stresses keep articular cartilage contained during compression
83
what is most predictable of crack formation?
shearing forces
