Connective Tissue Brainscape

Question 1

Major Components of Connective Tissue

Answer 1

• Fibers
o Collagen
o Elastin
• Ground substance with associated tissue fluid
• Cellular substances
o Fibroblast (osteoblasts in bone, chondrocytes in cartilage)
o Cells specific to each CT type

Question 2

Type I Collagen

Answer 2

o Resistance to tension
• Ligaments, bone, dermis, fibrous cartilage, epimysium, perimysium, endomysium, fascia, joint capsule, meniscus, mature scar

Question 3

Type II Collagen

Answer 3

o Resistance to intermittent pressure

• Loosely packed, no fibers, very thin fibrils such as hyaline and elastic cartilage, menisci

Question 4

Type III Collagen

Answer 4

o Structured maintenance for organs

• Loosely packed, thin fibrils such as smooth muscle in CV and GI systems

Question 5

Type IV Collagen

Answer 5

o Support and filtration

• Thin amorphous such as basement membrane

Question 6

Collagen Arrangment Determins Tissue Type. True/False

Answer 6

TRUE

Question 7

Collagen Arrangements

Answer 7

• Tendon
o Closely packed and roughly parallel
• Ligament
o Not as parallel as a tendon but more organized than a capsule
• Joint capsule
o Loose weave of interlaced fibers

Question 8

Collagen aligns purposefully according to direction of force or stress

Answer 8

• If no activity collagen does not align well

* Early movement allows for better alignment and motion

Question 9

Purpose of Connective Tissue

Answer 9

• Support
• Strength
• Repair
• Mechanical connector between cells

Question 10

Characteristics of Connective Tissue

Answer 10

• Abundant and diverse
• Provides tensile strength
• Weaker at tissue intersurface–>Strongest in the middle
• Vascularity is generally poor with the exception of bone
• Neural innervations are abundant (except in cartilage): muscle spindle, GTO

Question 11

Elastin

Answer 11

Provides elastic properties by their unique cross linking

Question 12

Inflammatory Phase

Answer 12

• The first phase of recovery after damage has occurred
• Initiates the healing process
• A rapid response to injury

Question 13

Four Cardinal Signs of Inflammation

Answer 13

• Erythema
• Heat
• Edema
• Pain

Question 14

Inflammatory Phase Progression

Answer 14

Vasoconstriction→Vasodilatation→Clot Formation→Phagocytosis

Question 15

Proliferation Phase

Answer 15

• Second phase of healing
• Involves connective tissue (strengthen the site) and also epithelial cells (cover the wound)
• Epithelial cells form the covering of mucous and serous membranes and the epidermis of the skin

Question 16

What Happens During Proliferation?

Answer 16

o Epithelialization
o Collagen Production
o Wound Contraction
o Neovascularization

Question 17

Clot Formation

Answer 17

• Platelets are the first cells at the site of the injury.

* Platelets bind to the exposed collagen and release fibrin to stimulate clotting

Question 18

Collagen Formation During Proliferation Phase

Answer 18

• Fibroblasts → procollagen → tropocollagen → collagen fibrils → collagen filaments → collagen fibers
• Tissue containing newly formed capillaries and myofibroblasts is called granulation tissue

Question 19

Tissue Response to Loading

Answer 19

• Tensile loads are resisted primarily by collagen fibers
o These fibers respond by straightening from their resting position
o During the elastic phase, the collagen fibers respond in a linear fashion up to 4% elongation
o After the load, the tendon returns to its resting length
• If the tensile force elongates the tissue more than the 4%, plastic changes begin to occur

Question 20

Viscoelastic Properties of Tissues

Answer 20

• A function of the ground substance
• A viscous material is resistant to flow, and an elastic material returns to the original state following deformation and after the force is removed
• The duration of the applied load and the rate at which the load is applied impact a tissue’s viscoelasticity

Question 21

Creep

Answer 21

o When a load is applied for an extended period of time, the tissue elongates, resulting in permanent deformation. The amount of deformation depends on the amount of force and the rate at which the force is applied.

Question 22

Relaxation

Answer 22

o When a tissue is pulled to a fixed length a certain force is required. As the tissue is held at this length, the amount of force necessary to maintain that length decreases
o How less force is required over a set amount of time

Question 23

Effect of Creep and Relaxation Together

Answer 23

• Allow connective tissue to adapt to and function in a variety of loading conditions without being damaged
• Tissues pulled into tension lengthen and relax, which provides the rationale for stretching exercises to lengthen shortened soft tissue

Question 24

Stress and Strain

Answer 24

• Stress
o The resistance of the intermolecular bonds to physical deformation when external loads are applied
• Strain
o The amount of displacement a material undergoes when a force is applied

Question 25

Stress Strain Curve

Answer 25

Illustrates how as force is applied, connective tissue will deform, and in doing so will create an internal stress/tension

Question 26

Factors Than Influence Connective Tissue

Answer 26

• An increase in temperature increases elasticity • Force magnitude, (defined by magnitude, time, and direction), influence the performance of CT o Low force applied slowly may cause tissue deformation o High forces applied quickly may cause tissue failure o Moderate force applied in a repetitive manner may cause tissue failure o Injury may occur from any of the above conditions

Question 27

Effect of Age on Connective Tissue

Answer 27

Gets tighter | o Lose hydration in tissue, decreasing mobility, increasing stickiness

Question 28

Effect of Immobilization

Answer 28

o No significant remodeling going on due to the lack of stress. o After 4 weeks of immobilization, muscle can lose up to 80% of the strength o Collateral ligaments of knee can lose up to 40% o Ground substance: dehydration, increase in intermolecular bonding, adhesion, bonding

Question 29

Effect of Inflammation

Answer 29

o Chronic information – results in loss of movement in joint, collagen is in a irregular fashion, not strong

Question 30

Strategies for prevention and reduction of contractures

Answer 30

Immobilize in lengthened position, introduce stress early, control inflammation, stretching, positioning

Question 31

Key Points for Connective Tissue

Answer 31

• Slow stretch will allow ground substance to more easily deform (elongate) • If your goal is to have strong CT, then create forces in the direction you want collagen laid down during remodeling • The amount of force depends on the goal o High forces applied quickly will result in tissue failure o Low forces applied over time will gradually elongate o Less force will be required to hold a given length over time, therefore increase force and change length

Question 32

Other Things to Remember for CT

Answer 32

* Place CT in lengthened position during immobilization if possible * Viscoelastic properties are influenced by temperature, force and time * COLLAGEN ALLIGNS ITSELF IN THE DIRECTION OF THE FORCE APPLIED

Question 33

Implications for Therapists

Answer 33

* It has been found that regular mobility of affected tissue helps maintain the lubrication and critical fiber distance * Immobilization is associated with increased deposition of connective tissue along with loss of water in the tissue (dehydration) and an increase in intermolecular cross linking, further restricting the extensibility of the tissue * What can we do to deter the negative affects that immobilization has on tissue/healing tissue

Question 34

John Barnes Myofascial Release

Answer 34

* Not a lot of research to support this, evidence based supported * Lots of reliance on patient preference and clinical experience, less on research * It is unproven whether these techniques can break the collagen cross links and allow lengthening and realignment