1
Q
What type of tension do type I and II collagen resist?
A
- type I- tension
2. Type II- tension and compression
2
Q
What are examples of proteglycans?
A
- GAG- glycosaminoglycan
2. hyaluanate- proteglycan monemer + hylauronic acid
3
Q
What is the primary function of proteglycans?
A
imbibition of the collagen matrix to allow for increased tissue mobility because the collagen tropocollagen is inelastic
4
Q
How does static stretching of collagen effect tissue tolerances?
A
It decreases it for a given amount of time based on the amount of deformity
5
Q
What role to type C free nerve endings play in the collagen healing process?
A
- .they are left behind in the scar as the capillaries are destroyed by the pressure of the condensing scar
- consequently excessive scaring can become painful
6
Q
How are mechanical forces transferred to the fibroblast?
A
Integrens are the primary mechanism for transferring mechanical energy to the cell
7
Q
What cell is predominately active during the inflammatory stage of healing and what are they doing?
A
macrophages
- destry cellular debris
- synthesize and secrete fibronectin to attract fibroblasts into the area
8
Q
what causes primary degeneration of tissue following immobilization?
A
loss of hyaluronic acid and GAG due to inadequate stimulation of fibroblastic for production of proteoglycans
9
Q
What treatment activities help reduce muscle tone?
A
- manual techniques for inhibition of target tissue
- removal of chemical stimulants of type IVs
- repeative painfree ROM
10
Q
How should ice be dosed in acute injury?
A
frequently applied every 10-15 minutes
11
Q
how does tissue healing effect muscle tone?
A
inhibits muscle tone
12
Q
How many types of collagen have been identified in the human body and how are they differentiated?
A
19 types
-they are distinguished by the types and sequencing of their amino acids
13
Q
What cells are primarily responsible for synthesizing type I collagen?
A
- fibroblasts
- osteoblasts
- odontoblasts
14
Q
What cells are primarily responsible for synthesizing type II collagen?
A
chondroblasts
15
Q
What cells are primarily responsible for synthesizing type III collagen?
A
- fibroblasts
- smooth muscle cells
- schwan cells
- hepatocytes
- mesenchymal precursor cells
16
Q
Where do you tend to find type II collagen
A
- hyaline cartilage
- elastic cartilage
- vertebral discs
17
Q
Where do you tend to find type III collagen?
A
bone, skin, smooth muscle, arteries, uterus, liver, spleen, kidney, lung, tendong, periosteum , endoneurium
18
Q
What are the functions of type III collagen?
A
- structural maintenance in expandable organs
- wound healing
- mediating the attachements of tendon, ligaments, and periosteum to bone cortex
- first type of collagen produced in wound healing later replaced by type I
19
Q
Describe the collagen tissue formation process?
A
- fibroblasts manufacture procollagen in endoplasmic reticulum
- three procollagen chains form into a triple helix
- triple helix transported out of IR and end components are removed to form tropocollagen
- tropocollagen binds to old collagen via hydorxylysine link with weak ionic bonds
- tropcollagen aligns itself side to side and end to end to form microfibrils
- microfibrils are bundled to form fascicles bundles in with crimped lines
20
Q
How do the tropocollagen bonds change over time as they become collagen>
A
- the new hydroxy-lysine links formed by one lysine amino acid attaching to an OH molecule by an ionic bond
- after about 6 months the ionic bond is replaced by a covalent bond (they share an electron) and you can no longer break the bond by gross deformity
21
Q
What solid structures make up the ground substance or ECM of tendons, ligaments, and articular cartilage?
A
- glycoproteins
- plasma proteins
- proteglycans
- collagen
22
Q
What inputs are required for scar tissue formation?
A
- macrophages
- prostaglandins
- oxygen
23
Q
What are the cellular events for over production of scar tissue?
A
1.during inflammation traumatize cells release neurotransmitters, histamine, bradykinins, prostaglandin E
2macrophages in the presence of oxygen and protaglandin E will increase in number
3.increased macrophages bring in more fibroblasts for over production of collagen
24
Q
What are the chemical and cellular mediators of the different stages of tissue healing?
A
- inflammation-histamine, bradykinin, prostaglandin E, Fiborgen, leucocytes
- fiborblasitic: capillaries, macrophages, fibroblasts
- remodeling: covalent cross linking, colagenase, MTLS
25
What neural tissue is left behind as the scar tissue is condensed?
Type IV C free nerve endings
26
When does scar tissue end shrinkage and covalent bonding occur?
6-12 months
27
How long does it take for ligament and tendons to close in after trauma
3-5 weeks
28
When does fibroblast in growth occur after trauma?
1-3 days
29
When does serofibrin appear at the wound site>
within minutes
30
How long does it take for capillary in-growth to begin after trauma?
1-3 days
31
How long does the closing of muscle and skin take after trauma
5-8 days
32
At what point after trauma does scar tissue begin to form?
8-10 weeks
33
What are the general guide lines for dosing for collagen?
1. frequency: multiple session per days
2. intensity: low intensity and strain rates
3. time:long duration spread out over several sessions per day.
4. type:simple planar in function movement patterns
5. away from direction of the injury
34
What direction and range should you use with collagen injuries?
1. away from the pain
| 2. mid to shorten range
35
How would OSR vary between contractile and non contractile collagen injuries?
1. noncontractile more functional in nature
| 2. contractile more use of eccentric training models
36
Is time or force more important when mobilizing collagen form improved plasticity?
1.time- 10-15 seconds 3x for 90% plastic deformity
37
How does heat effect collagen?
1. denatures collagen
2. increases ROM by pain and tone inhibition
3. decrease toe region of stress/strain curve
38
How can soft tissue work be used in collagen repair?
normalization of muscle tone via inhibitory afferent input to allow
- functional movement patterns
- appropriate metabolic activity
39
How does tension effect collagen fibroblast function?
1. stimulate fibroblast protein synthesis for GAG and hyalurarnic acid production
2. creates osmotic changes and imbibition for nutrient transfer
3. stimulates fibroblast for creating 3D collagen lattice
4. stimulates fibroblasts to produce collagen and to elongate
40
In what way can mechanical stimulation alter cell function?
```
It alters...
1.ion transport
2.protein synthesis
3.secretion
4.expression of specific genes
...effects can last up to an hour post strain
```
41
What is growth factor Beta-1 and what does it do?
1. found in osteocytes, chondrocytes, endochondral bone and articular cartilage
2. increases type I collagen synthesis in osteoblasts
3. plays a role in regulation of cartilage matrix and bone formation during remodeling
42
What is insulin-like growth factor I and what effect does it have on collagen?
1. polypeptide synthesized by a variety of tissues
| 2. stimulates the synthesis of collagen in bone, tendon and fibroblasts
43
How does insulin-like growth factor II effect collagen?
stimulates type I collagen formation in bone
44
How does platelet derived growth factor impact collagen?
1. stimulates type I collagen in bone cells
| 2. observed in macrophages close to the periosteum during early bone repair
45
What makes up ligaments and tendons?
1. connective tissue 20% cellular material, and 80% EC material
2. ligaments:60-70% water with collagen accounting for 70--80% of the dry weight
3. tendon: dry weight up to 86% collagen
46
What is the half life of collagen?
300-500 days
47
What chemical mediators are typically present during the inflammatory stage of healing?
1. histamine
2. serotonin
3. bradykinins
4. prostaglandins
48
What role does fibronectin play in collagen healing?
during the inflammatory response it is secreted by macrophages to attract fibroblasts into the area
49
What happens in the collagen production stage of healing in ligaments?
1. Fibroblasts over take macrophages as the dominate cell
2. collagen content increases over the first 4 weeks
3. week 2 the gap is bridges by fibrils of type I collagen
4. growth factor beta-1 and platelet derived GF also faciliate collagen production
50
What happens in the collagen production stage of tendon healing?
1. Fibroblasts over take macrophages as the dominate cell
2. collagen content increases over the first 4 weeks
3. by day five fibroblasts are overparticular to the tendon
4. edontendon production of fibroblast increases through 21-42 days
5. sheath synovial tissue repair three weeks with vascular adhesions
51
What is the primary cell in the remodeling phase of healing and what is it doing?
myofibroblast
1. capable of producing fiber like fibroblasts and contracting like smooth muscle
2. as the myofibroblast moves it pulls the collagen along with the myofiborblast anchoring strand
3. as the matric is condensed the MFB relaeases fibronectin to attract more FB
4. can work for up to 9 months
52
How does complete healing of tendon and ligaments differ?
1. tendon- there is minimal histological difference between injured and uninjuried tendons after after about week 20
2. ligament- loss of mechanical properties occur due to increased concentration of type III collagen
53
What is the remodeling phase of collagen healing?
1. after day 28 collagen re-orientation is complete
2. myofibroblasts begin to contract the new collagen and new cross links are formed via new tropocollagen
3. typically the repair is complete by day 128-135, but the MFB can be active up to 9 months
54
How does immobilization effect the histology of tissues?
1. distorts cellular allignment
2. decreased thickness of collagen
3. decreased tendon girth and lubrication
4. decreased stability of enthesis organ
5. collagen destroyed at higher rates.
6. water loss of 4% at 9 weeks
7. after 9 weeks GAG with 40% loss of HA, 30% chontrotin, and 10% dermaten sulfate
8. adipose build up in joint space
55
In what ways does cellular activity become more catabolic during immobilization?
1. lysosomal hydrolazse activity for breaking down GAG
| 2. lactic dehyrogenase and malic acid dehydrogenase for procollagen synthesis decrease
56
What are the four main theories on tendonopathy?
1. collagen breakdown
2. celluar breakdown
3. matrix breakdown
4. hypoxia
57
What is the order of tissue breakdown with tendonopathies?
1. tenocyte abnormalities
2. matrix abnormalities
3. neovascularization
4. collagen breakdown
58
How doe the plastic and elastic ranges differ clinically?
1. elastic range is at the begining
| 2. plastic range is at the end of motion
59
What mechanoreceptors are active in the different parts of the ROM?
```
rest: type I
elastic begining range type I and II
plastic mid range type II
plastic end range type I adn III
trauma type IV
```
60
How does heating effect collagen?
1. shorten elastic range due to collagen loss
2. 45 C rupture will occur at 1/4 of the tension it normally does
3. collage damage can occur as low as 37-40 C
61
At what point in the tendonopathy breakdown cycle does pain begin?
1. usaully at the point of neovascularization
| 2. there doesn't have to be pain at all
62
Why would eccentric exercises work better for tendonopathie than concentrics?
1. greater levle of tension to stimulate celluar response for repair
2. eccentric work uses 25% of the O2 consumption compared to the other 75% during concentric
3. decreases meovascularization
63
How can NSAIDs interfer with teonopathy recovery? corticosteriods?
1. NSAID delay or impair regenerative response and changes protein absorption
2. corticosteriods inhibit collagen synthesis
64
how does ice benefit an acute injury? harm?
```
BENIFIT
1reduce pain
2.reduce guarding
3.local vasoconstriction
4.reduce metabolic tissue rates
5.decreased fluid viscosity
HARM
1.sympathetic vasodialation after a few minutes
```
65
What is the stress strain curve for collagen?
1. toe region- gradual increase as the collagen as the crimps are removed and is considered the normal physiologic range
2. linear region- exponential increase in strain with microfractures of collagen
3. progressive failure- enough failure so the rate increase of strain begins to decrease
4. major failure- significant flattening with loss of teniosn
5. complete failure
66
A max tetanic contraction will put collagen in what range of its stress strain curve?
it cannot exceed the toe region
67
At what point in deformation do you exceed plastic range of bone, collagen, or elastin?
bone-5%
collagen- 20%
elastin- 100%
68
Beyond the toe region what other mechanism will resist collagen lengthening?
1. disproportionate covalent bonding strengths will allow adjacent chains to slide on each other
2. molecular size
3. molecular approximation
4. chain branching
5. cross-link
6. unwinding of loose helical arrangement of molecules
69
How does eccentric loading prior to concentric contraction effect performance?
1. takes of collagen slack allow for greater effiecency of force transmission
2. creates a functionally longer tendon and shorter muscle belly
- shorter muscle belly allows for a slower concentric contraction
- slower concentric contractions generate greater peak torque
70
Wow can you create more energy from the tone region of a tendon?
Make the tendon thicker
71
How will immobilization of a week effect the stress strain curve of collagen?
since you loose GAG you will have a decrease in the toe region
72
how doe the viscoelastic properties of collagen effect its performance?
The greater the speed the force is applied the form force the collage generates
73
What are the deformity properties of collagen?
1. elongation 1-1.5% for less than one hour causes no perminate change
2. .2-2% for an hour transient melting of tropocollagen
3. up to 2% requires 24 hours to recover
4. 3-8% causes lengthening by tearing
