Intro

Question 1

What are the 5 components of the MSK system?

Answer 1

1. Bones
2. Muscles
3. Joints = 2 bones meet
4. Tendons = connect muscle and bone
5. Ligaments = connect bone and bone

Question 2

What are the 5 functions of the skeleton?

Answer 2

1. Rigidity —> support
2. Movement
3. Protection
4. Mineral storage —> homeostasis
5. Blood cell production (bone marrow)

Question 3

What is the structure of the skeleton?

Answer 3

206 bones + variable sesamoids (270 in children)
- Appendicular —> pectoral girdle, pelvic girdle, limbs
- Axial —> cranium, vertebral column, rib cage

Question 4

What are the 2 components of bone?

Answer 4

1. Cells - osteogenic, osteocyte, osteoblast, osteoclast
2. ECM - osteoid (organic), minerals (inorganic)

Question 5

What are the 4 types of bone cell and their functions?

Answer 5

1. Osteogenic = bone stem cells
2. Osteocyte = mature bone cells
   - osteoblast embedded in osteoid
   - direct osteoclasts/blasts depending on
   mechanical strain
3. Osteoblast = bone forming cells
   - secretes osteoid + catalyses
   mineralisation
4. Osteoclasts = bone breaking cells
   - dissolve and resorb bone via
   phagocytosis
   - from bone marrow

Question 6

What is BMD?

Answer 6

Bone Mineral Density
- balance between osteoblast and osteoclast activity
- low BMD = osteoperosis (osteoclast > osteoblast)

Question 7

What are the 4 drugs used to treat osteoperosis?

Answer 7

Inhibit osteoclast acitvity:
1. Bisphosphinates (eg. alendronate)
2. Denosumab - antibodies inhibiting RANKL

Stimulat osteoblast activity:
3. Teriparatide - recombinant parathyroid hormone
4. Romosozumab - antibodies inhibiting sclerostin

Question 8

What are the 3 types of bone fracture?

Answer 8

1. Trauma —> high/low energy
2. Stress —> abnormal stress
3. Pathological —> abnormal bone

Question 9

What are the 5 types of bone diseases?

Answer 9

1. Cancer - bone metastases
   - myeloma
   - primary (rare)
2. Osteoperosis - menopause, age, glucocorticoid
3. Endocrine/metabolic - hyperparathyroidism
   - osteomalacia (vit D deficient)
4. Paget’s disease - inc bone turnover
   —> enlarge, fractures, deafness
5. Genetic - osteogenesis imperfecta
   - sickle cell anaemia —> osteonecrosis

Question 10

What is arthritis?

Answer 10

Disease of joints

Question 11

How are joints classified? (6)

Answer 11

Structural:
1. Fibrous —> no space
- skull sutures, tibia/fibula syndesmosis
- synarthroses or amphiarthroses
2. Cartilaginous —> cartilage between
- vertebrae
- synarthroses or amphiarthroses
3. Synovial —> synovial fluid between
- knee, hip, shoulder
- diarthroses

Functional:
1. Synarthroses —> no movement
2. Amphitherosis —> limited movement
3. Diartheroses —> free movement

Question 12

What are the 5 types of synovial joints?

Answer 12

1. Hinge —> monoplanar
   - knee
2. Ball and socket —> multiplanar
   - shoulder, hip
3. Pivot joint —> limited rotation
   - cervical spine
4. Condyloid —> all except pivotal
   - wrist

Question 13

What are the 3 components of synovial joints?

Answer 13

1. Articular cartilage:
   
   • Outer coverage
   • Type 2 collagen, proteoglycan (aggrecan)
2. Synovium:
   
   • Lining —> 1-3 cell deep
   • Synoviocytes —> Type A (phagocytic)
     —> Type B (produce hyaluronic acid)
3. Synovial fluid:
   
   • Inner
   • Hyaluronic acid-rich

Question 14

What is the function of cartilage in the MSK system?

Answer 14

Smooth lining at joint —> minimise friction

Question 15

What are the 4 types of arthritis?

Answer 15

Non-inflammatory:
1. Osteoarthritis - degenerative loss of cartilage

Inflammation-associated:
2. Autoimmune - rheumatoid
3. Crystal - gout —> urate crystals
- pseudogout —> CPPD crystals
4. Septic - joint bacterial infection

Question 15

What are the 2 components of cartilage?

Answer 15

1. Chondrocytes
2. ECM - Water
   - Collagen
   - Proteoglycans —> mainly aggrecan
   (chondroitin sulfate chains, keratin sulfate
   chains, hyaluronic acid —> aggregates)
   - avascular

Question 16

What 6 questions should be asked in a join pain history?

Answer 16

1. History of injury
2. Onset - osteo —> slow (months-years)
   - autoimmune —> subacute (weeks-months)
   - crystal —> rapid (hours)
   - septic —> rapid (hours)
3. Effect - osteo —> worse with movement
   - rheumatoid —> worse with inactivity
4. Morning stiffness —> inflammatory
5. Swelling
6. Systemic disturbance - septic —> fever

Question 17

What are the 3 functions of muscle?

Answer 17

1. Move bones around a joint
2. Respond to load and usage (hypertrophy/atrophy)
3. Protection

Question 18

What is the function of ligaments in the MSK system?

Answer 18

Connect bone to bone
- Restrict joint movement
- Stability and proprioception

Question 19

What is the function of tendons in the MSK system?

Answer 19

Connect muscle to bone
- Transmit force (80% collagen)

Question 20

What are 3 properties of ligaments and tendons?

Answer 20

1. Strong soft tissue
2. Mostly type I collagen
3. Less blood supply than muscle

Question 21

What are the 2 types of tendon injury?

Answer 21

1. Acute —> tear
2. Chronic —> overuse
   - eg. lateral epicondylitis (tennis elbow)
   —> tendinopathy - disordered collagen
   - neovascularisation
   - eg. achilles tendinopathy

Question 22

What are 2 examples of ligament injuries?

Answer 22

1. Lateral ligament ankle sprain
2. Anterior cruciate knee ligament injury