Term
| Name the 3 sections of a long bone, and where each is located |
|
Definition
1. Epiphysis - head of bone
2. Metaphysis - between two other zones where growth occurs
3. Diaphysis - the shaft |
|
|
Term
|
Definition
| The CT sheath that covers bones |
|
|
Term
| (T/F) The periosteum provides blood supply to bones |
|
Definition
|
|
Term
|
Definition
| The lining of the medullary cavity |
|
|
Term
| What is contained within the endosteum? |
|
Definition
|
|
Term
| (T/F) This is the site of hematopoiesis |
|
Definition
|
|
Term
| Which 4 bones does this process occur in in adults? |
|
Definition
1. Sternum
2. Cranium
3. Ribs
4. All long bones |
|
|
Term
| What are the two bone types? |
|
Definition
1. Spongy (cancellous/trabecular)
2. Compact (cortical) |
|
|
Term
| Name 4 components of compact bone structure |
|
Definition
1. Haversian system
2. Lamellae (matrix rings)
3. Haversian canals
4. Osteocytes in lacunae |
|
|
Term
| What are the two components of a bone's composition, and what contribution does each component contribute? |
|
Definition
1. Collagen matrix - the "scaffolding"
2. Hydroxyapatite (Ca10(PO4)6(OH)2) - the "bricks" |
|
|
Term
| What determines the composition of a bone? |
|
Definition
| Balance between osteoblast and osteoclast activity |
|
|
Term
| What is the function of osteoblasts? |
|
Definition
- Ca2+ deposition
- Increases alkaline phosphotase |
|
|
Term
| What is the function of osteoclasts? |
|
Definition
| - Bone resorption (breaking down bone) to release calcium |
|
|
Term
| How is osteoclast/osteoblast activity regulated? |
|
Definition
|
|
Term
| What type of receptors do osteoclast precursors have? |
|
Definition
|
|
Term
| What two substances do osteoblasts make? |
|
Definition
1. RANK ligand
2. Osteoprotegrin (OPG) |
|
|
Term
|
Definition
| - Stimulates osteoclast activity when it binds with RANK-R on osteoclasts |
|
|
Term
| What does OPG do? How does it do this? |
|
Definition
- Inhibits osteoclast activity
- Joins with RANK-L therefore no binding at RANK-R |
|
|
Term
| (T/F) Estrogen presence decreases OPG synthesis |
|
Definition
|
|
Term
| (T/F) In men, testosterone is converted to estrogen in bone by aromatase |
|
Definition
|
|
Term
| Which two substances (hormonal or otherwise) increase osteoclast activity? |
|
Definition
|
|
Term
| (T/F) Vitamin D3 needs to be activated before it induces osteoclast activity |
|
Definition
|
|
Term
| Which organ activates it, and what is active vitamin d3 (1,25-D3) called? |
|
Definition
- Kidney (renal activation)
- Calcitriol |
|
|
Term
| What does calcitriol cause, other than bone resportion? |
|
Definition
| Increased GI absorption of Ca2+ and PO4 |
|
|
Term
| What does increased Ca2+ and PO4 on the blood trigger? |
|
Definition
| Bone mineralization by osteoblasts |
|
|
Term
| What is the effect of growth hormone on bone remodeling? |
|
Definition
| GH increases osteoblast activity therefore increased bone formation |
|
|
Term
| What is the effect of cortisol on bone remodeling? |
|
Definition
| Cortisol causes removal of the bone matrix by stimulating osteoclasts |
|
|
Term
| What is responsible for cartilage production? |
|
Definition
|
|
Term
| Describe how bones are lengthened |
|
Definition
1. Chondrocytes produce cartilage
2. Osteoblasts invade the newly synthesized cartilage
3. Cartilage phosphate becomes calcified by osteoblasts, making it more rigid |
|
|
Term
| Where does bone growth occur? |
|
Definition
|
|
Term
| (T/F) Androgens stimulate the close of the epiphyseal plate |
|
Definition
|
|
Term
| What is complete bone trauma? Incomplete? |
|
Definition
| A complete fracture; a partial fracture |
|
|
Term
| Describe what occurs with a greenstick break, and what type of trauma is this? |
|
Definition
- Bone splits similar to a young tree (doesn't brake cleanly)
- Incomplete |
|
|
Term
| Why is a greenstick fracture more likely to occur with children? |
|
Definition
| Because their bones are still developing, therefore do not have a full mineralization and are more flexible |
|
|
Term
| What is an open break? A close break? |
|
Definition
| Open = bone penetrates skin; closed = break remains within tissue |
|
|
Term
| What is a segmented fracture? A comminuted fracture? |
|
Definition
Segmented: only two pieces created - 1 fracture line
Comminuted: bone has broken into several pieces - multiple fracture lines |
|
|
Term
| List the 3 common fracture types, and describe each |
|
Definition
1. Transverse - 90 degree angle to the bone
2. Spiral - One part of bone is twisted
3. Oblique - at a diagonal to bone axis |
|
|
Term
| List 4 other types of bone fractures? |
|
Definition
1. Impacted
2. Pathological
3. Stress
4. Depressed |
|
|
Term
| Describe impacted fractures |
|
Definition
| Fracture caused by bone segments being driven into each other |
|
|
Term
| Describe pathological fractures |
|
Definition
| The bone is made weak by a pathology |
|
|
Term
| Describe stress fractures |
|
Definition
| Fracture is not through the entire bone, but multiple fracture lines that weaken the bone overall |
|
|
Term
| Describe depressed fractures, and where they usually occur |
|
Definition
| Bones are displaced inwards - usually happens in the skull (blunt force trauma) |
|
|
Term
| List the two special types of fractures |
|
Definition
|
|
Term
| What occurs in a Colles' fracture? |
|
Definition
| Occurs at the distal radius, where the tips of the radius are broken off |
|
|
Term
| What occurs in a Pott's fracture? |
|
Definition
| Occurs at the ank;e, can break the tips of the fibula/tibia off |
|
|
Term
| List common symptoms of fractures? |
|
Definition
swelling
loss of function/deformity
crepitus (sound of bone breaking)
pain
early numbness |
|
|
Term
| List the pathophysiological steps to a fracture, and what occurs in each |
|
Definition
1. Bleeding/hematoma - under the periosteum
2. Granulation tissue is formed
3. Procallus formation
4. Bony callus created
5. Remodelling |
|
|
Term
| What is responsible for forming the procallus? |
|
Definition
|
|
Term
| What is osteogenesis, and what step does it occur at? |
|
Definition
| "Throwing bone in wherever you can" - creation of the bony callus |
|
|
Term
| What cells are the most important for bone remodeling, how long does the remodeling occur for, and what is the purpose of it? |
|
Definition
- Osteoclasts
- 3-4 months
- Removes parts of the bony callus that are not needed |
|
|
Term
| List the 5 factors that affect bone healing |
|
Definition
1. Degree of damage
2. Inflammation/blood supply
3. Approximation
4. Foreign material
5. Systemic factors |
|
|
Term
| What is approximation? What two things does it consist of? |
|
Definition
| How well the bones are realigned to their original position. Reduction and immobilization |
|
|
Term
| What is the purpose of reduction? |
|
Definition
| Getting the bones into their original alignment |
|
|
Term
| What is the purpose of immobilization? |
|
Definition
| Preventing motion so that calcium and phosphate is laid down right away |
|
|
Term
| What is depridement, and why is it important for bone healing? |
|
Definition
- Removal of foreign material from the site of break
- Important because foreign materials increase recovery time |
|
|
Term
| List 3 systemic factors that affect bone repair |
|
Definition
1. Diabetes
2. Glucocorticoids
3. Nutrition |
|
|
Term
| List 6 complications that can arise with healing? |
|
Definition
| Muscle spasm Infection Ischemia Compartment syndrome Fat emboli Non-union |
|
|
Term
| How do muscle contractions complicate healing, and how is this combated? |
|
Definition
- Change approximation (unalign bone)
- Traction - counteracts muscle spasms and ensures proper approximation |
|
|
Term
| What is compartment syndrome? |
|
Definition
| Initial swelling after trauma can squeeze nerves and vessels, leading to reduced healing |
|
|
Term
|
Definition
|
|
Term
| How is compartment syndrome avoided? |
|
Definition
| By utilizing multiple casts over the healing process to ensure proper fit |
|
|
