Lecture 15 (bones + joints)

Question 1

Sprain vs Strain

Answer 1

Sprain = ligament, Strain = Tendon or Muscle

Question 2

Four tissues of MSK

Answer 2

nerve: motor, sensory, glial
connective: fascia, tendon, ligaments, cartilage, bone, blood
muscle: skeletal, smooth (blood vessels)
epithelium: epidermis, endothelium (blood vessels), synovial membrane

Question 3

Bone development

Answer 3

• Cartilage develops: mesenchymal cells –> chondroblasts
• Cartilage grows: chondrocytes divide
• Primary ossification centre in diaphysis
• Medullary cavity: osteoclasts breakdown center
• Secondary ossification centres: in epiphyses
• Articular cartilage + epiphyseal plate: both remain cartilage
• Epiphyseal plate closes: bone stops growing

Question 4

Marrow

Answer 4

Yellow marrow: adipocytes (fat) in diaphysis
Red marrow: stem cells in epiphysis

Question 5

Bone formation

Answer 5

stem cells –> osteoblasts (forms matrix of tissue) –> osteocyte –> broken down by osteoclasts

Question 6

Osteoclasts

Answer 6

dissolves bone and releases Ca+

Question 7

Ca+ blood levels

Answer 7

Bones store Ca+

Question 8

Avascular necrosis

Answer 8

lack of blood flow to bone leading to cell death

Question 9

Bone remodelling

Answer 9

bone continuously remodels in response to stress, spongy bone *trabeculae form pillars in an organized manner

Question 10

Types of fractures

Answer 10

Simple: injury only to bone
Compound: bone pierces skin

Question 11

Subtypes of bone fractures (6)

Answer 11

Comminuted: multiple splinters
Compression: crushed vertebrae (typically due to osteoporosis)
Spiral: helical tear due to rotational force (common in sports)
Epiphyseal: at growth plate/epiphyseal line (typically in development)
Depressed: blunt force trauma
Greenstick: partial fracture (common in kids)

Question 12

4 steps in bone healing

Answer 12

• Hematoma formation
• Fibrocartilaginous callus formation: Collagen attaches the bone
• Bony Callus Formation: cartilage into
• Bone Remodelling: extra bone needs to be broken down

Question 13

Ligaments

Answer 13

Bone to bone connections

Question 14

Tendons

Answer 14

Muscle to bone

Question 15

Apneurosis

Answer 15

broad, flat tendon

Question 16

Fibrous joint

Answer 16

most stable, no movement, eg: skull and tib-fib

Question 17

Cartilaginous joint

Answer 17

medium stable, some movement, eg: ribs and pelvic bones (loosen during pregnancy)

Question 18

Synovial joint

Answer 18

Bone - Bone friction: least stability, most movement, eg: fingers
has joint capsule and articular cartilage

Question 19

Types of synovial joints

Answer 19

simple: synovial membrane covers both bones
complex: articular disc (meniscus) between bones

Question 20

Synovial joint problems

Answer 20

Synovitis: inflammation of synovium
Arthritis: inflammation of cartilage + synovium
Osteoarthritis: inflammation of bone + cartilage

Question 21

Bursa

Answer 21

Skin - Bone friction: Synovial membrane full of synovial fluid, eg: acromion of scapula, knee, elbow…

Question 22

Tendon sheaths

Answer 22

Tendon - Bone friction: synovial membrane around tendons

Question 23

Tendonitis

Answer 23

inflammation of tendon sheath

Question 24

Bursitis

Answer 24

inflammation of Bursa

Question 25

Joint shapes + movement

Answer 25

Saddle: two Y’s
Pivot: rod in hole
Ball and socket: self explanatory
Hinge: also
Condyloid: loose hinge
Plane: two plates

Question 26

Flexion and Extension

Answer 26

Bent and Straightened

Question 27

Scapula movement

Answer 27

Protraction (inwards)
Retraction (backwards)

Question 28

Circumduction

Answer 28

circular movement

Question 29

Thumb Movement

Answer 29

Adduction: upwards (with palm up)
Abduction: towards palm
Flexion: towards index
Extension: away from index
Opposition: pinky to thumb (‘fold’ hand)

Question 30

Foot movement

Answer 30

Eversion: inner foot on floor
Inversion: outer foot on floor (rolled ankle)
Dorsiflexion: foot up
Plantar Flexion: foot pointed