What are the 3 main types of joints?
- Synovial
- Fibrous
- Cartilaginous
Explain what fibrous joints are and give an example of them
They are joints which unite bones by fibrous tissue (doesn’t allow any movement)
E.g. sutures which unite the bones of the skull
Explain what cartilaginous joints are and give examples of them
These are joints which unite bone by cartilage (limited movement)
e.g. Intervertebral Discs; Pubic symphsis; Part of the sacroiliac joints; Costochondral joints
Describe the general structure of synovial joints
These joints are where the bone is separated by a cavity (containing synovial fluid), and united by a fibrous capsule (and extra articular structures e.g. ligaments, bursa etc)
What is the inner aspect of a fibrous capsule in a synovial joint lined with and what is the function of this lining?
Synovial membrane - produces synovial fluid
What are the articular surfaces of bones in a synovial joint covered with ?
Articular cartilage
What are the overall physiological functions of joints?
- Structural support
- Purposeful motion
What is the role of joints during purposeful movement ?
- Stress distribution
- Confer stability - due to shape of articular component e.g. hip joint, ligaments, synovial fluid
- Joint lubrication
What are the main functions of synovial fluid ?
- Lubricated joint
- Facilitates movement - by reducing friction
- Helps minimise wear and tear due to lubrication
- Supplies chondrocytes with O2 and nutrients and removes waste and CO2 (also aids nutrition of articular cartilage)
What are the main characteristics of synovial fluid ?
- Continually replenished by synovial membrane
- Has a high viscosity due to presence of hyaluronic acid
- Contains few cells - mainly mononuclear leucocytes
Describe the normal appearance of synovial fluid
Normally it is clear and colourless
What happens to the WBC in synovial fluid in septic and inflammatory arthritis ?
It increases
What causes synovial fluid to turn red?
Traumatic synovial tap and in haemorrhagic arthritis
Read over the gross appearance of synovial fluid in health and disease
Match the description to the different test tubes:
- Synovial fluid from joint with mild synovial inflammation
- Synovial fluid obtained from a severely inflamed joint. It is thin and opaque due to a very high polymorph count
- Synovial fluid from joint with mild synovial inflammation. The blood stain is caused by trauma
- Normal synovial fluid. It is viscous and clear
A.Normal synovial fluid. It is viscous and clear
B.Synovial fluid from joint with mild synovial inflammation
C.Synovial fluid from joint with mild synovial inflammation. The blood stain is caused by trauma
D.Synovial fluid obtained from a severely inflamed joint. It is thin and opaque due to a very high polymorph count
What are the main functions of articular cartilage ?
Helps prevent wear and tear of joints
Distributes contact pressure to subchondral bones
Describe the general strucutre of hyaline cartilage
It has special extracellular matrix (ECM) made predominantly of:
- Water (70%)
- Collagen (20%) -mainly type II contributes most to the elastic behaviour of cartilage
- And proteoglycans (10%)
What is the most common type of articular cartilage ?
Hyaline cartilage
Describe the mechanical properties of the main components of cartilage:
- Water
- Collagen
- Proteoglycan
Water - Maintain the resiliency of the tissue and contribute to the nutrition and lubrication system
Collagen - To maintain cartilage architecture and provide tensile stiffness and strength
Proteoglycan - Responsible for the compressive properties associated with load bearing
The ECM in cartilage is synthesized, organised, degraded and maintained by what cell ?
Chondrocytes
What in terms of physiology could cause joint disease ?
- Changes in the relative amounts of the 3 major components of cartilage (changes its mechanical properties
- Joint disease would also occur if the rate of ECM degradation exceeds the rate of its synthesis
What are the markers of cartilage brakedown?
- Serum and synovial keratin sulphate
- Type II collagen in synovial fluid
What gives rise to OA ?
Cartilage and synovial composition and function deteriorate with age and repeated wear and tear giving rise to osteoarthritis
In terms of physiology what causes rheumatoid arthritis ?
Synovial cell proliferation and inflammation cause rheumatoid arthritis
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overview-of-the-lower-limb - part 129
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overview-of-the-lower-limb - part 27
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Muscle Physiology 125
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Muscle physiology 220
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Microbiology - MSK infections 122
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Joint physiology26
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Bone structure and core MSK histology22
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MSK Pathology 124
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MSK pathology 25
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Microbiology - MSK infections 210
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Physiology and pharmacology of the skeletal neuromuscular junction - neuro wk 3 deck better14
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Physiology: pain (not relevant for finals)20
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benign MSK tumours18
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Benign (but locally aggressive) MSK tumours12
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Malignant MSK tumours22
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biochem cortex34
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Pathology cortex 121
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Pathology cortex 211
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Anatomy dissection 1 (any additional points not mentioned in lecture is here)25
