Bone biology / response to exercise

Question 1

What cells are found in bone?

Answer 1

*Osteoblasts
*Osteocytes
*Osteoclasts

Question 2

What is the function of bone?

Answer 2

*Skeletal support
*Protection
*Haematopoiesis - bone marrow
*Regulation of mineral homeostasis
*Fat storage

Question 3

What is the general bone structure?

Answer 3

*Diaphysis = shaft / central part of long bone
*Metaphysis = trumpet shaped end of long bones
*Epiphysis = end part of bone - initially growing

Question 4

Where are trabecular (cancellous) and woven bone found?

Answer 4

*Metaphysis
*Flat bones
*Cuboidal bones

Question 5

What is cortical bone? What is its function?

Answer 5

*Dense bone of diaphysis
*Supports weight, protects organs, provides levers for movement

Question 6

What is intramembranous ossification? Where is it seen?

Answer 6

*Seen in flat bones - skull, scapula
*Direct production of bone by osteoblasts - most don’t have marrow cavity

Question 7

What is endochondral ossification? What is it seen in?

Answer 7

*Seen in long bones
*Formation + replacement of cartilage template by bone
-increase bone length - physis

Question 8

What stimulates bone growth?

Answer 8

*Genetic template
*Hormones
*Load

Question 9

What is Wolff’s law?

Answer 9

*Primary regulator of bone remodelling
*Bone will adapt to life / exercise depending on load and strength needed

Question 10

What are the different forces on a bone?

Answer 10

*Compression
*Tension
*Shearing
*Torsion
*Bending

Question 11

What is elastic deformation?

Answer 11

– With loading and unloading, the bone deforms but then returns to the original shape
– Stimulates modelling

Question 12

What is plastic deformation?

Answer 12

– With loading and unloading, the bone deforms but does not return to its original shape
* Microcracks
* Cyclic fatigue
* Incomplete fractures
– Stimulates remodelling

Question 13

When do fractures occur?

Answer 13

• Complete failure of bone
  – Elastic –Plastic - Failure
• Weakening of normal bone structure
  – Plastic deformation and repetitive loading = stress fractures
  – Abnormal matrix
• Metabolic
• Neoplasia

Question 14

What are external trauma causes of failure of bone?

Answer 14

*Kick wound - cow to dog
*Hit by car

Question 15

What are internal trauma causes of failure of bone?

Answer 15

*Foot planted + body twists - limb trapped in gate/ stuck in hole

Question 16

Where are stress fractures likely to occur in race horses?

Answer 16

• MCIII/MTIII condylar fracture
• dorsal metacarpal disease
• cuboidal bones
• tibia
• humerus
• ilial wing

Question 17

Where are stress fractures likely to occur in greyhounds?

Answer 17

*Acetabulum
*Central tarsal bone

Question 18

What is stress remodelling?

Answer 18

– This is repetitive application of non-supra physiological load
– When bone remodelling
cannot keep up with bone
damage

Question 19

What are noeplasias of the bone?

Answer 19

**Osteosarcoma
*Haemangiosarcoma
*Multiple myeloma
*Chondrosarcoma

Question 20

What are metabolic bone disease?

Answer 20

• Parathyroid hormone abnormality
• Vitamin D deficiency
• Paraneoplastic

Question 21

What is metabolic bone disease related to?

Answer 21

*Metabolism of calcium + phosphorus

Question 22

What is metabolic bone disease controlled by?

Answer 22

– Vitamin D –amount of sunlight = Increases Ca from GIT
– Parathyroid hormone = Removal of Ca from bone, decreases excretion from kidneys and increased Vit D formation
– Calcitonin –removal of calcium from blood