Connective Tissue and Articular Cartilage Flashcards Preview

DPT Biomechanics > Connective Tissue and Articular Cartilage > Flashcards

Flashcards in Connective Tissue and Articular Cartilage Deck (50):
1

Type II collagen is found in

Hyaline cartilage. thinner than type I, lower tensile strength, provide framework, structure for other tissues

2

Where is elastin found?

hyaline cartilage, ligamentum flavum

3

GAGs are found in Ground Substance, have a ____charge and are Hydro_____

negative, philic

4

What does the water provide in ground substance

diffusion of nutrients, provides mechanical properties

5

Where are fibroblasts found?

ligaments, tendons, Supportive CTs

6

Where are Chondrocytes found?

hyaline articular cartilage, fibrocartilage

7

composition of dense connective tissue

HIGH type I collagen, LOW elastin and fibroblasts

8

ligaments, tendons, and capsules are examples of

dense connective tissue

9

These characteristics describe which type of tissue

poor healing (low vascularity), adapts to stress/strain with increased stiffness (increased collagen and GAG synthesis)

10

Where is irregular dense connective tissue found?

joint capsule

11

Which type of Dense connective tissue is resistant to tensile forces in MULTIPLE directions?

Irregular (joint capsule)

12

how is collagen arranged in irregular dense connective tissue?

irregular in ground substance

13

Which type of connective tissue is orderly and has a parallel arrangement of collagen?

Regular Dense Connective Tissue

14

Which has more elastin? Ligament or Tendons

Tendons - transmit large forces from muscle to bone

15

Regular dense connective tissue in ligaments and tendons resist tension along the _____ axis

longitudinal

16

How long is the Inflammatory Phase of healing?

1-10 days

17

How long is the Proliferation (consolidation) phase?

3-30 days

18

How long is maturation (remodeling) phase

3-360 days

19

Which phase of healing are neutrophils and macrophages active?

Inflammatory phase

20

What is the body's natural response to injury

inflammatory phase

21

Connective Tissue is rebuilt with _____ tissue in the proliferation phase

granulation

22

Fibroblasts are active in which phase of healing

proliferation

23

In Maturation phase, collagen remodels from Type ___ to Type ___

III to I

24

On a load-deformation curve, describe the plastic region

top of plateau to the ultimate failure point

25

In Load-Deformation curve, what is the elastic region

the slope

26

The yield point in the load deformation curve is where which two sections meet?

elastic and plastic

27

In a stress strain curve, what is the area under the curve

energy

28

the slope of elastic region in a stress strain curve is

stiffness

29

Since biological materials are viscoelastic, there is a toe region. describe it

non linear region. before the elastic region

30

When does viscoelastic creep occur

when exposed to a constant load

31

What type of stretches are thought to bring on plastic changes to connective tissue

slow, low-intensity, and long-duration stretches

32

What does the slope look like in the stress strain curve when we add a faster loading rate

steeper slope and increase stiffness

33

Stress-relaxation is a stress response that occurs when exposed to a constant ______

deformation

34

describe what is occurring when there is a high rapid high initial stress followd by a slow decreasing stress required to maintain the deformation

stress-relaxtion

35

Name the type of collagen: thick, little elongation, stiff, strong, binds, supports bony articulation
found in: ligaments, fibrous Joint capsules, tendons

Type 1

36

The organic matrix of articular cartilage makes up 15-30% of the volume. What provides the structural framework?

Collagen (Type II) within proteoglycan solution

37

List one function of articular cartilage

1. increase area of load distribution for joints
2. attenuate joint contact stresses
3. provide a smooth, wear resistant bearing surface

38

What makes up the majority of the composition of articular cartilage?

water, salts, glycoproteins, lipids - 60-85% of volume
Organic matrix - 15-30%
chondrocytes - 10%

39

Why is there a near frictionless behavior between joint surfaces?

synovial fluid

40

Mechanical properties of Articular cartilage

high tensile stiffness and strength
cannot resist compression well
anisotropic - collagen fiber arrangement and densities vary
bi-phasic material - fluid and solid

41

Where is water concentrated in the articular cartilage?

near articular surface

42

What does water permit in articular cartilage

exchange of gases nutrients and waste products between chondrocytes and synovial fluid

43

What supports more than 90% of the applied load on a joint?

pressurization

44

The magnitude of stress required to maintain the equilibrium displacement decreases over time. what definition is this?

stress-relaxation.

45

What is shear stiffness of articular cartilage from.

collagen only, not interstitial fluid flow in pure shear

46

What is the splitting of the cartilage surface called?

Fibrillation

47

What happens to water content and permeability in the degeneration of articular cartilage?

they both increase

48

Changes in collagen and PG content and structure
Loosening of structure (increased permeability and fluid content)
increased fluid flow and decreased ability to resist loading are all indicators of what?

osteoarthritis

49

What are the three proposed mechanisms for the wearing out of cartilage?

1 - tensile failure of collagen fiber network- accumulated tissue damage leads to lower strength
2 - 'washout' of PGs from extracellular matrix from repeated fluid exudation resulting in decreased stiffness and increased permeability
3 - rapid application of high loads - no time for stress- relaxation ( fluid redistribution) resulting in high stresses that may cause damage

50

An anatomical example of a 2nd class lever and explain why it's 2nd class.

The foot is an example of a 2nd class lever when in plantar flexion because the load (BW) is between internal force (calf muscles) and the fulcrum(ball of the foot)