Connective Tissue

Question 1

what are the main functions of CT

Answer 1

support, strength, repair, mechanical connectors

Question 2

what are the strongest and weakest parts of CT

Answer 2

weakest at intersurface

strongest in the middle

Question 3

what is CT composed of

Answer 3

elastin and collagen fibers, ground substance, cells specific to each CT; fibroblasts (osteoblast, chondrocytes)

Question 4

arrangement of collagen in a tendon

Answer 4

parallel, closely packed

Question 5

arrangement of collagen in a ligament

Answer 5

not as parallel, semi-organized

Question 6

arrangement of collagen in a joint capsule

Answer 6

loose weave of fibers

Question 7

Type I Collagen

Answer 7

RESISTS TENSION: ligament, bone, dermis, fibrous cartilage, epimysium, perimysium, endomysium, fascia, joint capsule, meniscus, mature scar

Question 8

Type II Collagen

Answer 8

RESIST INTERMITTENT PRESSURE: loosely packed, no fibers; hyaline/elastic cartilage, menisci

Question 9

Type III Collagen

Answer 9

structured maintenance for organs: loosely packed, thin fibrils like smooth muscle

Question 10

Type IV Collagen

Answer 10

support and filtration: thin, amorphous, like basement membrane

Question 11

how is collagen formed

Answer 11

tropocollagen–collagen fibrils–collagen fibers

Question 12

why is collagen important clinically

Answer 12

• -it aligns based on force and stress

- if no activity, won’t align well–move early

Question 13

why do we need to understand healing phase of CT

Answer 13

know how to improve the phases; progress is predictable, know how strong tissue is at point in time

Question 14

length of inflammatory phase

Answer 14

1-6 days

Question 15

four signs of inflammatory phase

Answer 15

erythema, heat, edema, pain

Question 16

four phases of inflammatory phase

Answer 16

vasoconstriction (decrease blood loss)
vasodilation (increase capillary permeability)
clot formation (platelets first cells to site)
phagocytosis (monocytes–macrophages–phagocytosis)

Question 17

four processes of proliferation phase

Answer 17

epithelialization, collagen production, wound contraction, neovascularization

Question 18

epithelialization

Answer 18

protects area against infetion–cells form barrier which can resurface area in up to 48h

Question 19

collagen production

Answer 19

fibroblasts–procollagen–tropocollagen–collagen fibrils–collagen filaments–collagen fibers.
granulation tissue contains myofibroblasts and new capillaries, type III collagen

Question 20

wound contraction

Answer 20

occurs 5 days in, peaks at 2 weeks: myofibroblasts pull inward.

Question 21

primary intention

Answer 21

rapidly closed with sutures

Question 22

secondary intention

Answer 22

wound closes on own time

Question 23

neovascularization

Answer 23

occurs due to angiogenesis; new vascular networks anastamose

Question 24

clinical impact of the proliferation phase

Answer 24

the scar will be red, swollen, fragile–worry about adhesion and keeping scar mobile

Question 25

remodeling phase duration

Answer 25

12-24 months, most seen in 3-4 months

Question 26

elastic phase

Answer 26

where collagen elongates and returns to normal

Question 27

plastic phase

Answer 27

where collagen stretched past 4% and causes change

Question 28

viscoelastic properties

Answer 28

function of ground substance; duration of load and rate impact a tissues viscoelasticity

Question 29

characteristics of CT: Creep

Answer 29

when a constant load is applied and the tissue elongates resulting in permanent deformation that depends on rate and force

Question 30

characteristics of CT: relaxation

Answer 30

when tissue is pulled to a fixed length a certain force is needed; as it is held there, the force needed decreases

Question 31

stress

Answer 31

resistance of intermolecular bonds to physical deformation with external loads

Question 32

strain

Answer 32

amount of displacement a material undergoes when force is applied

Question 33

describe stress-strain curve

Answer 33

the stiffer the material the steeper the slope. toe is where the fibers are recruited, elastic is where they become tight plastic is where some fibers begin to fail

Question 34

what influences Connective Tissue

Answer 34

``` temperature force magnitude age immobilization inflammation ```

Question 35

clinical implications of the remodeling phase

Answer 35

``` prevent/reduce chance of adhesion/contracture lengthen in immobilization introduce stress early introduce movement early control/reduce inflammation ```