week 5 part 2

Question 1

Articulating bone ends are lined with articular cartilage

Answer 1

• Chondrocytes – maintain the cartilage
• Secrete different enzymes to balance breakdown of old and
  production of new cartilage
• Extracellular matrix
• Collagen - structural support
• Proteoglycans (hyaluronic acid, keratin sulfate, chondroitin
  sulfate) – provide elasticity & high tensile strength

Question 2

Synovial membrane forms inner lining of joint

Answer 2

• Loose connective tissue
• Blood vessels
• Cells that clear debris and cells that secrete synovial fluid (fills
  the joint cavity with fluid)

Question 3

Outer fibrous joint capsule protects the joint

Answer 3

• Attaches to bone
• Reinforced with ligaments

Question 4

Osteoarthritis

Answer 4

Considered a disease of Mechanical Degeneration + Inflammation of a Synovial Joint
* Localized to the affected joint
* A result of ‘something’ that causes increased release degradative enzymes by chondrocytes  Favors breakdown of cartilage

Question 5

Osteoarthritis – Signs, Symptom

Answer 5

• Often on weight-bearing joints, Asymmetric, <4 joints
• Beginning and End-of-Day Stiffness, increases with activity
• Pain with movement and weight bearing
• Limited ROM
• Localized inflammation possible
• Enlarged joint that can harden as osteophytes develop
• Crepitus may be heard

Question 6

Osteoarthritis treatment

Answer 6

• Minimize stress placed on joint
• Exercise, Physiotherapy
• Pharmacological Tx: Anti-inflammatories, analgesics
• Hyaluronic acid or corticosteroid Injections
• Surgery to repair or replace

Question 7

Rheumatoid Arthritis – Signs &
Symptoms

Answer 7

• 3+ joints affected, symmetrically
• More frequently begins in the finger joints (interphalangeal, metacarpophalangeal)
• Chronic morning stiffness that lasts for at least 1 hour
• Stiffness often improves throughout the day
• Decreased range of motion, pain, swelling, redness, warmth
• Joint deformities with disease progression
• Potential Blood markers:
• elevated blood CRP
• Elevated Erythrocyte Sedimentation Rate (ESR)
• Elevated Rheumatoid Factor
• Systemic symptoms: Fever, fatigue, loss of appetite, weight loss, Affecting
  other areas of the body: eye, skin, organs (lungs, heart, liver),
  blood vessel walls

Question 8

steps of osteoarthritis

Answer 8

1. Something triggers chondrocytes to release degradative enzymes
   2.Favors breakdown of cartilage
   3.Small pieces of cartilage break off into the joint space
   4.Cells of the synovium try to remove debris
   5.Cracks form in the in cartilage  Synovial fluid enters and widens cracks
   6.No longer have a smooth articular surface with even load distribution
   Bone is eventually exposed & rubs against articulating bone
   7.bone Eburnation (looks like polished bone),

Question 9

steps RA

Answer 9

1.Autoimmune response
2.Inflammation of the synovial membrane
3.Cytokines trigger synovial cells to proliferate
4.Forms a Pannus (Thickened and inflamed synovial membrane with granulation scar tissue)
Pannus releases proteolytic enzymes and cytokines.
5.Destruction of the cartilage
6. Pannus becomes more fibrotic over time  calcification  Ankylosis
* Nutrient supply within the joint is cut off
* Articulating bones exposed  erosion, degradation, possible osteophytes, cysts
* Antibodies continue to activate inflammatory mediators

Question 10

Ankylosing Spondylitis

Answer 10

• Chronic Inflammatory Disease
• Affects vertebral joints  makes them stiff
• Thought to be autoimmune + genetic predisposition

Question 11

steps Ankylosing Spondylitis

Answer 11

1.Inflammatory / Immune response
2.Destroys the intervertebral, facet and sacroiliac joints
3.Fibroblasts replace destroyed joints with fibrin
4.Eventually fibrous tissue ossifies through activation of osteoblasts