Musculoskeletal Flashcards
What is the mineral phase of bones made of?
Hydroxyapatite
a calcium phosphate
What is the organic phase of bones made out of?
Collagen and other proteins
Role of osteochondral progenitor cells
Undifferentiated stem cells
Role of osteoblasts
make new bone
role of osteocytes
maintain the activity of the bone
Role of osteoclasts
Removes (resorbs) old bone cells for renewal
Structure type of cortical bone
compact
structure type of cancellous/trabecular bone
Spongy bone
When does Endochondral ossification mostly occur
In Utero
What makes endochondral ossification different to Intramembranous ossification
Endochondral ossification occurs around a cartilage base
Bone remodelling process
stage 1
- Bone lining cells retract due to activation by mechanical or biochemical stimulus
Bone remodelling process
stage 2
Osteoclast attraction and fusion to become activated. Osteoclast digestion of underlying bone
Bone remodelling process
step 3
Osteoblasts move into the resorption cavity, forming a new bony matrix that is subsequently calcified
Ossification definition
Bone tissue formation, may form in any region with fibroblasts, excess calcium and adequate blood supply
Calcification definition
Calcium salts build up in tissues, causing it to harden, may happen in any mesenchymous tissue of low metabolism
Factors affecting bone growth
Mechanical Hormones Nutrients Ageing Disease
Location of hyaline cartilage
4 answers
End of synovial joints,
ribs to sternum,
larynx and nose,
reinforces trachea and bronchi
What forms hyaline cartilage?
Type two collagen fibres
Location of fibrocartilage?
Areas of high stress (vertebral discs, menisci)
What forms fibrocartilage?
Type one collagen
Less matrix and more collagen so is more compressible
How much calcium does the body contain?
1Kg
What three factors regulate calcium levels?
- Parathyroid hormone (PTH)
- Vitamin D
- Calcitonin
Action of PTH on the kidney
- Increases calcium resorption in distal tubes
- Increase in phosphate excretion
- Increases formation of vitamin D
General action of PTH
Stimulates bone resorption
Actions of Vitamin D on bone
Stimulates bone Resorption process
Actions of vitamin D on intestine
- Stimulates calcium absorption
- Stimulates phosphate absorption
What is osteomalacia?
Vitamin D deficiency in adults
What is rickets?
Vitamin D deficiency in children
Action of calcitonin
Opposes the effect of PTH
What secretes PTH?
Parafollicular cells of the parathyroid gland
Calcium levels fall (4 parts) -effect on kidneys? -effect on vitamin D? -effect on intestine?
- Parathyroid gland secretes PTH
- Increasing resorption of calcium in kidneys
- Increased activation of vitamin D
- Increased Ca absorption from intestine
- Calcium levels increase
Bone density definition
A measure of the amount of minerals present in the bone
factors affecting bone density
3
- Substrate availability
- Physiological factors
- Hormones/ steroid hormones
What is a torus fracture?
The bone buckles but the surface integrity on the convex side is maintained.
What is a greenstick fracture?
Bone is bent, damage to concave side but incomplete
Salter Harris fractures
Fractures including the growth plate
Causes of rickets
3
- Prematurity
- Maternal vitamin D deficiency
- Lack of sunlight
Symptoms of rickets
Skeletal changes and growth pain
Osteopenia definition
Reduced bone density
Bone mineral density score between -1 and -2.5
Effects of age on bone
2
- Resorption greater than formation
- Osteoporosis
Sarcopenia definition
The accelerated loss of muscle mass and function.
Acute pain : . Duration? . Aetiology? . Purpose? . Examples?
. Short
. Result of injury/disease
. important protective role
. fracture, sprain, acute-post operative pain
Chronic pain: . Duration? . Aetiology? . Purpose? . Examples?
. Long (<3-6 months)
. Can be related to tissue damage, can persist beyond normal healing
. No useful biological function
. chronic back pain, osteoarthritis
Prevalence of chronic pain
affects 15-44% of general population
Personal/social impact of chronic pain
disability stigma
inability to work
depression
