Physiology: Joints Flashcards Preview

RB Y2 MSK 02 - Rheumatology > Physiology: Joints > Flashcards

Flashcards in Physiology: Joints Deck (47)
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1
Q

fibrous joints

A
  • syndesmoses and sutures
  • dont allow any movement
2
Q

syndesmoses example

A

interosseous membrane between tibia and fibia

3
Q

example of 1y and 2y cartilaginous joint

A
  • 1y - hyaline cartilage on the end of bones
  • 2y - intervertebral discs
  • allow limited movement
4
Q

name 4 cartilaginous joints

A
  • pubic symphysis
  • intervertebral disc
  • part of SI joints
  • costochondral joints
5
Q

amphiarthorisis

A

cartilaginous joint

6
Q

diarthrosis

A

synovial joint

7
Q

what is the synovial membrane made up of

A

vascular connective tissue with capillary networks and lymphatics

8
Q

what does the synovial membrane do

A

contains synovial cells (fibroblast) which produce synovial fluid

9
Q

define simple synovial joint

A

one articular surface eg metacarpophalangeal joint

10
Q

define compound synovial joint

A

>1 articular surfaces eg elbow joint

11
Q

how are joints additionally supported

A

extra articular structures

12
Q

how does a joint confer stability during purposeful motion

A

shape of articular component, ligament and synovial fluid that acts as an adhesive seal

13
Q

how is joint lubrication provided

A
  • cartilage interstitial fluid
  • synovial fluid is made up of hyaluronic acid and lubrcin
14
Q

what does the synovial fluid supply the chondrocytes with

A

O2 and nutrients and removes Co2 and waste products

15
Q

where is the synovial fluid found

A

fills the joint cavity

16
Q

is the synovial fluid static pool or is it replenished

A

replenished and absorbed by synovial membrane

17
Q

what is the viscosity of the synovial fluid like

A
  • high
  • mainly due to hyaluronic acid (mucin) that is produced by synovial cells and is in the synovial fluid
  • varies with joint movement
18
Q

what cells does the synovial fluid normally contain

A

few mononuclear leucocytes

19
Q

describe the relationship between synovial fluid viscosity and elasticity and joint movement

A

rapid movement is associated with decrease viscosity and increased elasticity

20
Q

describe the relationship between synovial fluid viscosity and elasticity and joint movement on a person with a diseased joint

A

properties become defective - joint is more viscose and less elastic on movement

21
Q

what does normal synovial fluid look like

A

clear and colourless

22
Q

when would synovial fluid turn red

A

traumatic synovial tap and haemorrhagic arthritis

23
Q

what is the viscosity of inflammatory synovial fluid like

A

low

24
Q

what does a high polymorph count do to the colour of synovial fluid

A

makes it cloudy

25
Q

what are the functions of articular cartilage

A

prevents wear and tear, distributes contact pressure to subchondral bone

26
Q

describe the structure of articular cartilage

A
  • several zones that differ in organisation of collagen fibres and relative content of cartilage components
  • water is highest near the articualr surface
27
Q

what is the composition of the ECM of articular (hyaline cartilage)

A
  • 75% water
  • 25% type II collagen fibres and proteoglycans (made from GAGs)
28
Q

what are the functions of the water in cartilage

A

maintain resiliency of tissue and contribute to nutrition and lubrication

29
Q

what happens to the water nd collagen content of cartilage with age

A

decrease

30
Q

how is water distributed in cartilage

A

unevenly - mainly near articular surface

31
Q

what is the function of collagen in cartilage

A

type II maintain cartilage architecture and provide tensile stiffness and strength

32
Q

is there more collagen or proteoglycan in cartilage

A

collagen - 20% proteoglycan - 10%

33
Q

what is proteoglycan composed of

A
  • mainly GAGs
  • eg chondroitin sulphate
  • composition changes with age eg chondroiton decreases
34
Q

what is the function of proteoglycan

A

compressive properties that are associated with load bearing

35
Q

what is the ECM in cartilage made and maintained by

A

chondrocytes

36
Q

how does articular cartilage receive 02 and nutrients

A

avascular - via synovial fluid

37
Q

what substances degrade ECM

A

metalloproteinase proteolytic enzymes eg collagenase and stromelysin

38
Q

describe the rate of degradation and synthesis of ECM

A

usually balanced, joint disease occurs if degradation>synthesis

39
Q

name 2 catabolic factors for ECM turnover

A

TNF alpha and IL 1 (cytokines)

40
Q

name 2 anabolic factors for ECM turnover

A

TGF - beta and IGF 1

41
Q

name 2 markers of cartilage degradation

A
  • serum and synovial keratin sulphate
  • type II collagen in synovial fluid
42
Q

what do increased levels of keratin sulphate in serum and synovial fluid indicate

A

cartilage breakdown - increase in patients with OA

43
Q

what is type II collagen in synovial fluid marker useful for

A

evaluating cartilage erosion eg osteoarthritis and rheumatoid arthritis

44
Q

osteoarthritis

A

can be caused by cartilage and synovial composition and function deteriorate with age and repeated wear and tear

45
Q

what does deposition of salt (uric acid) crystals in joint cause

A

gouty arthritis

46
Q

what does synovial cell proliferation and inflammation cause

A

rheumatoid arthritis

47
Q

what does deposition of rhomboid shaped Ca pyrophosphate crystals cause

A

pseudo gout