Bone And Muscle

Question 1

What are the two different types of bone formation?

Answer 1

Endochondral (long bones, require growth plates)

Intramembranous (flat bones, no growth plate)

Question 2

What are the steps of intramembranous ossification?

Answer 2

1. Ossification center begins in fibrous connective tissue membrane
2. Osteoid is secreted into fibrous membrane- entrapped osteoblasts become osteocytes
3. Formation of woven bone and periosteum
4. Formation of final layer of compact bone

Question 3

What does growth plate function require?

Answer 3

Amgiogenesis

Question 4

How do you classify a fracture?

Answer 4

“OLD ACID”

Open vs closed
Location
Degree (complete vs incomplete)

Articular extension
Comminution/pattern
Intrinsic bone quality
Displacement, angulation, rotation

Question 5

What are the steps of fracture healing?

Answer 5

1. Hematoma
2. Fibrocartilagenous callus
3. Bony callus
4. Remodeling

Question 6

What are salter fractures?

Answer 6

Fractures through a growth plate
Can induce growth deformities
Classified by the fracture location

Question 7

What are the different types of salter fractures?

Answer 7

1- fracture straight through growth plate
2- fracture through and above growth plate
3- fracture through and below growth plate
4- fracture above and below growth plate
5- growth plate crushed

Question 8

What are the different types of bone dysphasia?

Answer 8

Craniomandibular osteopathy
Osteogenesis imperfecta
Osteopetrosis
Chondrodysplasia
Osteoporosis

Question 9

What is craniomandibular osteopathy?

Answer 9

"Lion jaw"
Bony proliferation of mandible
Primarily seen in westies and scotties
Autosomal recessive
3-7 moths, stops at 11-13 months
Causes pain, difficulty eating/drinking

Question 10

What is osteogenesis imperfecta?

Answer 10

Defect in matrix synthesis (type 1 collagen)

Characterized by excessive bone fragility, pathologic fractures

Question 11

What is osteopetrosis?

Answer 11

Failure of bone remodeling

Results in increased bone density

Question 12

What is chondrodysplasia?

Answer 12

Not just one syndrome

Achondroplasia , disproportionate dwarfism

Question 13

Osteoporosis?

Answer 13

Bone loss (restoration > formation)
Disuse, malnutrition, corticosteroids
Susceptible to fracture

Question 14

What is osteopenia?

Answer 14

Decreased number of trabeculae

Question 15

What are 3 metabolic bone diseases?

Answer 15

Scurvy
Fibrous osteodystrophy
Rickets

Question 16

What is scurvy?

Answer 16

Only in species lacking L-gluconolactone oxidase (guinea pigs)
Lack of vitamin C->
Decreased lysine and proline hydroxylation in collagen ->
Impaired collagen synthesis ->
Weakened vessel walls and physeal cartilage deformity ->
Periarticular hemorrhage and osteochodrodysplasia

Question 17

What causes fibrous osteodystrophy?

Answer 17

Primary hyperparathyroidism

Secondary hyperparathyroidism

Question 18

What is primary hyperparathyroidism?

Answer 18

Functional parathyroid adenomas
Or
Parathyroid hyperplasia

Question 19

What causes secondary hyperparathyroidism?

Answer 19

Ca:P imbalance in feed
Kidney disease

(Rubber jaw)

Question 20

What is rickets?

Answer 20

Defect in endochondral ossification in young animals caused by deficiency of vitamin D or phosphorous

Question 21

What is hypertrophic osteoPATHY

Answer 21

Has pathology!
Periosteum proliferation
Due to intrathoracic mass
Joints NOT involved

Question 22

What is hypertrophic osteoDYSTROPHY?

Answer 22

Bone disease of young dogs characterized by
“Double physeal line”
Acute inflammation in the primary spongiosa
Necrosis of osteoblasts

Dogs will be lame

Question 23

What is eosinophilic panosteitis?

Answer 23

Patchy radiodensity in medullary cavity, especially around nutrient foramen

Presents as shifting leg lameness

Question 24

What is Legg-Perthes disease?

Answer 24

Avascular necrosis of femoral head
Small breed dogs (especially toy poodles)
Occurs prior to physeal closure (4-11 months)

Question 25

What are some possible causes of osteomyelitis?

Answer 25

Surgery Penetrating wound Fractures Hematogenous spread

Question 26

Strophic rhinitis is associated with what bacteria?

Answer 26

Bordetella bronchiseptica and pasteurella multocida

Question 27

What is osteochondromatosis?

Answer 27

Benign growth at growth palate that grows with skeleton Uncommon Seen in younger cats

Question 28

What are diseases of the syovium?

Answer 28

Hypertrophy | Pannus

Question 29

What is pannus?

Answer 29

Granulation tissue on articular surface that can damage underlying cartilage and progress to ankylosis

Question 30

What is fibrillation of cartilage?

Answer 30

Formation of vertical clefts in cartilage | Dull, yellow-brown color

Question 31

What is eburnation?

Answer 31

Polishing of exposed subchondral bone

Question 32

What are the two types or arthritis?

Answer 32

Osteoarthritis | Inflammatory arthritis

Question 33

What causes inflammatory arthritis?

Answer 33

``` Acute infections (penetrating wounds, septicemia) Chronic infections (immune-mediated, viruses, untreated acute arthritis ```

Question 34

Arthritis in a goat is probably caused by

Answer 34

Caprine arthritis encephalitis

Question 35

What causes osteoarthritis?

Answer 35

Decreased proteoglycan synthesis | Increased metalloenzyme synthesis (degrades proteoglycans)

Question 36

What is osteochondritis dessicans?

Answer 36

Osteochondrosis where a cartilaginous flap breaks off and goes into joint

Question 37

If an aggressive lesion crosses joint, it is probably

Answer 37

Synovial cell sarcoma

Question 38

What is intervertebral disc disease?

Answer 38

Annulus fibrosis cracks, tears, or ruptures releasing nucleus purposes Types: 1- sudden 2- gradual

Question 39

What is dural ossification?

Answer 39

"Ossifying pachymeningitis" - bone in dura | Generally incidental

Question 40

What is hip dysplasia?

Answer 40

Typically a disease of large breed dogs ("bunny hopping" | Degenerative, noninflammatory deformation of joints causing subluxation of femoral heads

Question 41

What is elbow dysplasia?

Answer 41

Disease of large breed dogs (especially german shepherds) Degenerative, non-inflammatory Ununited anconeal process Fragmented medial coronoid process

Question 42

What are characteristics of normal skeletal muscle?

Answer 42

Myofibers Peripheral nuclei Striations High blood supply

Question 43

What are the types of muscle fibers?

Answer 43

Type 1- slow twitch, large numbers of mitochondria, postural and sustained activity Type 2- fast twitch, fewer mitochondria, rapid activity

Question 44

How are muscle injuries classified?

Answer 44

Distribution= focal or multifocal | Timeline- monophasic or polyphasic

Question 45

How does muscle respond to injury?

Answer 45

``` Hypertrophy Atrophy Degeneration Necrosis (+/- calcification) Regeneration Fibrosis ```

Question 46

What is muscle degeneration caused by, what does it look like, and what are examples?

Answer 46

Caused by decreased blood flow Muscle looks pale Downer cow, post-anesthetic myopathy in horses

Question 47

What are types and examples of myositis?

Answer 47

Bacterial - clostridium, abscesses Parasitic - toxoplasma, trichinella, sarcosystis Autoimmiune- lupus, polymyositis, purpura hemorrhagica

Question 48

If muscle looks black with gas pockets, what would you suspect?

Answer 48

Clostridium

Question 49

If muscle has white streaks, what would you suspect?

Answer 49

Sarcocystis

Question 50

What is masticatory muscle myositis (MMM)?

Answer 50

Unilateral atrophy of masticatory muscle

Question 51

What are some congenital myopathies?

Answer 51

``` Malignant hyperthermia Muscular dystrophy Equine rhabdomyolysis Hyperkalemic periodic paralysis Fainting goat syndrome Splayleg ```

Question 52

What are some nutritional myopathies?

Answer 52

Malnutrition- atrophy | Vitamin E/selenium deficiency - white muscle disease

Question 53

Mines in toxicity is most commonly seen in what species?

Answer 53

Horses

Question 54

What are neoplasias of skeletal muscle?

Answer 54

Rhabodomyoma | Rhabdomyosarcoma