MSK

Question 1

example of a long bone

Answer 1

femur, humerus

Question 2

example of a irregular bone

Answer 2

maxillary, mandibular

Question 3

describe primary and secondary bone

Answer 3

primary= trabecular bone, formed from endochondrial ossification, fast process, disorganised structure
secondary= lamellar bone, remodelled, organised structure, good strenght to weight ratios

Question 4

example of a flat bone

Answer 4

skull, sternum

Question 5

example of a sesmoid bone

Answer 5

patella, hyoid. These are bones within a tendon

Question 6

describe the 4 stages of fracture healing

Answer 6

1. haematoma formation- blood clot forms in bone and periosteal stem cells migrate to fracture site
2. inflammation- platelets in clot secrete cytokines which attract macrophages etc to the site. Oseoclasts reabsorb bone. Stem cells differentiate into osteoblasts
3. repair- osteoblasts produce osteiod and fibroblasts produce soft callus.
4. remodelling. calcified matrix of disorganised woven bone gradually becomes remodelled by the continuous absorption and production of lamella bone.

Question 7

give 3 reasons for bone remodelling

Answer 7

to obtain more calcium- for example in pregnancy
a response to force- during exercise
to reform the structure after a fracture- reorientate fibrils for mechanical strength

Question 8

intramembraneous ossification

Answer 8

osteoprogenitor cells form clusters in tissues and with the expression of cbfa-1 gene they differentiate into osteoblasts- secrete osteoid- bone formation

Question 9

endochondiral ossification

Answer 9

osteoblasts secrete osteoid over a cartilagenous bone model, at the emphyseal plate
requires the invasion of blood vessels in the primary ossification site for development to occur

Question 10

give 3 purposes of the skeleton

Answer 10

to protect the vital organs
to form joints for movement
to act as a source of minerals- calcium

Question 11

describe the adult bone matrix composition

Answer 11

50-70% hydroxyapetite
20-40% type one collagen (bone)
5-10% water

Question 12

type one collagen

Answer 12

bone

Question 13

type 2 collagen

Answer 13

cartilage

Question 14

type 3 collagen

Answer 14

forms reticulin, involved in artery formation and wound healing

Question 15

type 4 collagen

Answer 15

basement membranes

Question 16

type 5 collagen

Answer 16

fibrils of collagen, also found in the placenta

Question 17

type 6 collagen

Answer 17

microfibrillar cross linked collagen molecules

Question 18

extra-articular fracture

Answer 18

does not involve the joint

Question 19

intra-articular fracture

Answer 19

involves the joint

Question 20

principles of fracture management

Answer 20

1. reduce- put bones back together
2. stabilise- hold the bones together- pins, cast, sling
3. rehabilitate- physio- enable movement of the joint

Question 21

name 3 types of fracture fixation

Answer 21

1. intramedullary- nails into the bone from top down to secure fracture together.
2. external fixation- rings of metal around the bone- pins into the bone to secure it in place
3. extramedullary- plates and screws

Question 22

define redundacy

Answer 22

most functions of cytokines can be performend by many different cytokines. Hence no single cytokine will have limited effects on the system- bad method of treatment

Question 23

define pleiotropism

Answer 23

a single cytokine has many different functional effects on many cell types. hence it has a great effect on the system- a good method of treatment

Question 24

autocrine secretion

Answer 24

the substance secreted has the effect on the cell itself

Question 25

paracrine secretion

Answer 25

the substance secreted has the effect on nearby cells

Question 26

autocrine secretion

Answer 26

the substance secreted is released into the plasma and has a greater effect on distant regions of the body

Question 27

equation linking force, deformation of bone and strain

Answer 27

strain= change in deformation of bone/ the force the bone is exposed to

Question 28

approximate grams of calcium in the skeleton.

Answer 28

1200g. (extracellulary 1g)

Question 29

total serum calcium level

Answer 29

2.4mmol/l

Question 30

complexed calcium

Answer 30

bound to citrate of phosphate

Question 31

ionised calcium

Answer 31

metabolically active calcium

Question 32

non- metabolically active calcium

Answer 32

bound to proteins

Question 33

define a fracture

Answer 33

a breach in the continuity of bone

Question 34

immediate fracture complications

Answer 34

local- vessel/ nerve damage/ infection | general- shock/ fat embolism

Question 35

long term fracture complications

Answer 35

local- malunion of fracture/ ischaemia to fracture | general- osteoporosis/ reduced joint mobility/ pressure sores

Question 36

Dietary sources of potassium

Answer 36

soy, seeds, nuts, protein

Question 37

fibroblast growth factor 23 is produced in response to what and from where?

Answer 37

produced by osteocytes in responce to high potassium levels

Question 38

differences between a tendon and ligament

Answer 38

tendon: muscle to bone, has higher collagen content, highly organised fibres Ligament: bone to bone, worse blood supply, randomly arranged fibres. higher elastin content

Question 39

5 signs of inflammation

Answer 39

redness, swelling, hot temperature, loss of function and soreness

Question 40

3 types of investigation into joint pain

Answer 40

blood test, urine test, imaging, synovial fluid sample

Question 41

degenerative rheumatology

Answer 41

common in elderly people, pain gets worse with use, no inflammation and doesnt respond to NSAIDS

Question 42

inflammatory rheumatology

Answer 42

common in young people, pain eases with use, does respond to NSAIDS.

Question 43

composition of ligaments

Answer 43

extracellular matrix= 80% fibroblasts- remodel the extracellular matrix dense connective tissue to enable the ligament to sustain high tensile strengths sparse vascularisation- poor healing capacity

Question 44

major component of ligaments and tendon fibres

Answer 44

collagen

Question 45

what factor induces the excretion of potassium from the kidneys

Answer 45

fibroblast factor-23 which is secreted by osteocytes in response to high phosphate levels

Question 46

fibrous insertion site

Answer 46

a ligament or tendon is attached to bone by calcified collagen fibres- sharpey's fibres. abrupt change inserts into intramembranously ossified bone

Question 47

fibrocartilagenous insertion site

Answer 47

a ligament or tendon inserts into bone via a more gradual process. Collagenous ligament/tendon becomes fibrocartilage and then mineralised cartilage attaching to the bone bone is formed by endochondrial ossification

Question 48

name 5 factors affecting the mechanical properties of ligaments and tendons

Answer 48

1. pregnancy- hormones reduce the stiffness 2. age- 3. useage- over use/underuse 4. obesity- increased strain 5. mobilisation- stiff or extremely supple

Question 49

functional classification of joints and an example for each

Answer 49

synarthroses- immobile joints- skull sutures, peg in socket tooth joints amyarthroses- slightly movable joints- intervertebral discs diarthroses- freely movable joints- synovial- knee

Question 50

types of fibrous joint

Answer 50

sutures- between bones in the skull syndesmose joints- bones are connected by an interosseous membrane of fibrous tissue gomphoses joints- peg in socket joint

Question 51

types of cartilaginous joints

Answer 51

synchondroses- bones connected by hyaline cartilage symphses-- bones are connected by a plate of fibrocartliage intevertebral discs

Question 52

name 5 components of a typical synovial joint

Answer 52

``` synovial fluid menisci synovial membrane hyaline cartilage bursae ```

Question 53

6 types of synovial joint

Answer 53

``` hing joint- elbow saddle joint- carples-metacarples pivot joint- sacrum gliding joint- between carples condyloid joint- between metacarples and phalnges ball and socket- hip, shoulder ```