Musculoskeletal (1-4) Flashcards
1
Q
each fascicle in a muscle is composed of multiple of these
A
myofibers
2
Q
what are the 3 main functions of skeletal muscle
A
- maintaining posture and facilitating movement
- play role in respiration
- maintencance of body temp; glucose metabolism
3
Q
which myofiber type?
function: posture;
slow rate of contraction;
aerobic activity;
high oxidative activity, use lots of O2;
high myoglobin level;
gross color: red
A
type 1
4
Q
which myofiber type
function: exercise;
fast rate of contraction;
anaerobic activity;
high glycolytic activity, use little O2;
low myoglobin level;
gross color: white
A
type 2
5
Q
what are the 4 ways muscle responds to injury
A
- degeneration/necrosis
- regeneration
- atrophy
- hypertrophy
6
Q
what is the final common pathway of necrosis in muscles (as a response to injury)
A
excessive intracellular calcium
(leads to activation of destructive enzymes)
7
Q
what are the 3 requirements for muscle regeneration
A
- intact basal lamina (pportive scaffold)
- macrophages (blood supply)
- viable satellite stem cells
8
Q
what will occur if the 3 conditions required for muscle regeneration are not met?
A
fibrosis
9
Q
name 3 causes of muscle atrophy
A
- disuse
- denervation
- malnutrition, cachexia, old-age
10
Q
what is the classic histological lesion for denervation atrophy of muscles
A
angular atrophy of myofibers
11
Q
what is the cause of muscle hypertrophy
A
increased work load on myofibers
12
Q
this is inflammation of muscle
A
myositis
13
Q
wht are the two main causes of infectious myositis
A
- bacteria
- parasite
14
Q
what is the disease or manifestation caused by Clostridium chauvoei in sheep and cattle
(musculoskeletal)
A
Black leg
15
Q
what is the pathogenesis for black leg caused by Clostridium chauvoei in sheep and cattle
A
spores gain entry to GIT → blood → lie latent → under right conditions (usually anaerobic following injury) they germinate → bacilli grow → toxins → capillary damage
16
Q
what is the disease or manifestation of:
Truperella pyogenes, Streptococcus equi, Corynebacterium paratuberculosis
(musculoskeletal)
A
abscesses
17
Q
what is the disease or manifestation of:
C. septicum, C. novyi, C. perfringens, C. sordelli
(musculoskeletal)
A
gas gangrene
18
Q
what is the disease or manifestation of:
Actinobacillus lignieresii
A
wooden tongue
19
Q
name two immune-mediated causes of myositis
A
- canine masticatory muscle myositis (MMM)
- polymyositis
20
Q
what is the pathogenesis of canine masticatory muscle myositis (MMM)
A
autoantibodies selectvely attack type IIM fibers
21
Q
name the drug
coccidiostate toxic to horses, donkeys, zebra, cattle, sheep, dogs and birds;
disturbs transport of Na and K across cell membrane leading to incr. free calcium in the cells causing necrosis in heart and skeletal muscle
A
Monensin
22
Q
what is the cause of white muscle disease
A
selenium and/or vitamin E deficiency
23
Q
what is the pathogenesis of white muscle disease
A
oxygen free radicals (ORF) damage cell membranes → calcium entry and mitochondrial damage → cell swells and dies
(less selenium/vit E to mop up/neutralize ORFs)
24
Q
name the exertional myopathy
excercise following prolonged period of rest: unable to move, sweating, tremors;
breaking up of skeletal muscle so that myoglobin escapes from muscle cells, leaks into urine and damages renal tubes
A
equine exertional rhabdomyolysis
25
what causes acquired myasthenia gravis (MG)
antibodies directed against acetyl choline receptors
26
what causes congenital myasthenia gravis (MG)
born with deficiency in acetyl choline recepotors (rare)
27
what causes Botulism
ingestion of Clostridium botulinum toxin
28
what affect does Clostridium boltulinum toxin have on acetyl choline release
inhibits it
29
this is a benign primary tumor of muscle
rhabdomyoma
30
this s a malignant primary tumor of muscle
rhabdomyosarcoma
31
name 5 functions of bones
1. support
2. protection
3. movement
4. stem cell storage
5. mineral bank
32
what 2 things is bone composed of
1. cells
2. matrix
33
what 3 cells are in bone
1. osteoblasts
2. osteocytes
3. osteoclasts
34
# name the bone cell
mesenchymal cells of bone marrow stromal origin;
form the bone matrix, known as osteoid
osteoblasts
35
# name the bone cell
osteoblasts that have become surrounded by mineralized bone matrix;
occupy cavities called lacunae
osteocytes
36
# name the bone cell
multinucleated cells derived from hematopoietic stem cells;
responsible for bone resorption
osteoclasts
37
name 7 minerals found in bone;
accounts for 65% of bone
1. Ca
2. P
3. Mg
4. Mn
5. Zn
6. Cu
7. Na
38
what 2 things is the matrix of bone composed of
1. type 1 collagen
2. mineral
39
# name the bone organization
only normal in the fetus;
collagen is arranged in a "random weave"
immature (woven) bone
40
# name the bone organization
collagen is arranged in orderly layers which are much stronger than woven bone
mature (lamellar) bone
41
this is a sheath of connective tissue covering bone (except at the articular surfaces);
blood supply to mature bone enters through this;
damage to it triggers rapid formation of new or reactive bone
periosteum
42
this is essentially a remnant of the cartilage model located at the junction of diaphysis and epiphysis;
aka the growth plate
physis
43
name the 3 zones of the growth plate (physis) cartilage
1. reserve
2. proliferative
3. hypertrophic
44
what 2 hormones mediate bone resorption
1. PTH (parathyroid hormone)
2. calitonin
45
# name the hormone
produced by chief cells in parathyroid glands in response to decreased serum calcium;
activates osteoclasts;
binds to osteoblast receptors which detaches them from bone surface causing osteoclasts to incr. in number, attach to bone and resorb mineralized matrix (Ca2+);
parathyroid hormone (PTH)
46
# name the hormone
produced by C-cells in the thyroid glands in response to increased serum calcium;
inhibits osteoclasts to keep calcium inside the mineralized matrix
calcitonin
47
what are the two types of bone fractures
1. traumatic
2. pathological
48
this is when a normal bone is broken by excessive force
traumatic fracture
49
this is when an abnormal bone is broken by minimal or no trauma
pathological fracture
50
what are the 4 overlapping processes that contribute to bone fracture repair
1. inflammation
2. soft callus formation
3. hard callus formation
4. remodelling
51
lists the steps involved in fracture and fracture repair
1. fracture
2. periosteum tears, fragments displaced
3. hematoma formation, bone necrosis and inflammation
4. phagocytosis of necrotic bone
5. mesenchymal cells (fibroblasts, chondrocytes) proliferate in hematoma
6. fibroblasts and chondrocytes produce fibrous connective tissue and hyaline cartilage (soft primary callus)
7. vascularization of callus begins
8. woven bone formed by osteoblasts (hard secondary callus)
9. remodelling to mature lamellar bone (years)
52
name 4 factors which slow bone fracture healing
1. malnutrition
2. excessive movement
3. presence of necrotic bone
4. bacterial infection
53
name the 3 main nutritional/endocrine systemic diseases that can manifest in the skeleton and lead to metabolic bone disease
1. osteoporosis
2. rickets/osteomalacia
3. hyperparathyroidism (fibrous osteodystrophy)
54
# name the metabolic bone disease
most common;
reduction in bone quantity (not quality);
bone resorption exceeds formation leading to pathological loss of bone
osteoporosis
55
name 3 causes of osteoporosis
1. nutritional (most)
2. senility
3. physical inactivity
56
# name the metabolic bone disease
failure of mineralization which disrupts endochondral ossification at growth plates;
most due to diets low in vitamin D;
growth plates are thickened and metaphyses are flared;
disease of young, fast-growing skeleton
Rickets
57
# name the metabolic bone disease
disease of the adult skeleton;
results in failure of newly formed osteoid to mineralize;
cortex may be thin, spongy and soft in advanced cases;
mostly due to diets low in vitamin D
osteomalacia
58
# name the metabolic bone disease
bone is resorbed and replaced by fibrous, "rubbery" connective tissue and poorly mineralized immature bone;
due to persistently elevated PTH
fibrous osteodystrophy
59
name 3 secondary causes of elevated parathyroid hormone (PTH)
1. renal
2. nutritional
3. PTH secretion triggered by decr. plasma calcium
60
what is the pathogenesis of renal hyperparathyroidism
chronic renal failure → retention of phosphate & inadequate vit D production by kidneys → hyperphosphatemia and hypocalcemia → incr. PTH output → incr. bone resorption → fibrous osteodystrophy
61
what is the pathogenesis of nutritional hyperparathyroidism
low calcium/high phosphate diets → decr. serum calcium → incr. PTH → incr. bone resorption
62
# name the term
inflammation of bone
osteitis
63
# name the term
inflammation of periosteum
periostitis
64
# name the term
inflammation of medullary cavity (of bone)
osteomyelitis
65
# name the term
any disease of bone (non-specific)
osteopathy
66
what is the most common cause of inflammation in bone
bacteria
67
name 3 routes of infection of the bone
1. implantation
2. extension from other infected sites
3. hematogenously
68
name 4 consequences of bone inflammation
1. extension to adjacent bone
2. hematogenous spread to other bones and soft tissue
3. pathological fractures
4. sinus tracts to exterior
69
# name the osteopathy
young, fast growing dogs of large or giant breeds;
distal radius and ulna most severely affected;
bilaterally symmetrical;
welling of metaphyses of long bones, corresponding with neutrophilic infiltrate
metaphyseal osteopathy
70
name 2 benign bone tumors
1. osteoma
2. chondroma
71
# name the bone neoplasm
uncommon/rare; benign;
smoothly contoured, slow-growing and well-differentiated;
horses and cattle mainly;
flat bones (skull, scapula);
disfigurement, obstruct nasal passgaes
osteoma
72
# name the bone neoplasm
benign neoplasm of cartilage;
rare in animals;
slow growing and expansile with smooth border
chondroma
73
# name the bone neoplasm
malignant neoplasm of mesenchymal origin in which cells produce osteoid;
accounts for 85% of primary bone tumors in dogs (giant breeds esp. risk);
mostly appendicular skeleton;
poor prognosis due to early metastasis
osteosarcoma (OSA)
74
# name the bone neoplasm
malignant neoplasm in which mesenchymal cells produce chondroid matrix;
most common in dog;
flat bones;
slower growth rate, longer clinical course, later to metastasize;
metastatic rate: 20%
chondrosarcoma
75
name 4 circumstances where non-neoplastic bone proliferation can occur
1. fracture repair
2. chronic osteomyelitis
3. superimposed on a neoplasm
4. hyperostotic bone diseases
76
name 2 hyperostotic bone diseases
1. hypertrophic pulmonary osteopathy (HPO)
2. craniomandibular osteopathy
77
# name the hyperostotic bone disease
periosteal proliferation of bone on diaphyses and metaphyses of distal limbs;
progressive and bilateral;
most cases have intrathoracic neoplasm or chronic inflammatory focus
hypertrophic pulmonary osteopathy (HPO)
78
# name the hyperostotic bone disease
west highland white terriers and scottish terriers;
puppies: arise at 4-7 months;
bilaterally symmetrical;
periosteal proliferation of bone leading to irregular thickening of the mandibular rami and some skull bones
craniomandibular osteopathy
79
name 3 types of generalized bone dysplasias
1. proportionate dwarfism (not genetic)
2. chondrodysplasia
3. osteopetrosis
4. osteogenesis imperfecta
80
# name the generalized dysplasia
"abnormal cartilage development";
due to a genetic defect;
affects bones which form via a cartilage model (long bones are shorter than normal);
leads to disproportionate dwarfism
chondrodysplasia (chondrodystrophy)
81
# name the generalized dysplasia
failure of reabsorption by osteoclasts resulting in failure of remodelling of cancellous bone;
bones become thickened and dense but brittle;
genetic in origin
osteopetrosis (marble bone disease)
82
# name the generalized bone dysplasia
due to a defect in synthesis of type 1 collagen;
rare in animals;
genetic basis
osteogenesis imperfecta
83
# name the localize dystrophy
equine disease;
narrowing of the vertebral canal due to vertebral malalignment or maldevelopment;
fast growing male TBs ranging from 8mo to 4 y;
HL ataxia due to cord compression
cervical vertebral stenotic myelopathy ("wobblers")
84
# name the localize dystrophy
lateral deviation of distal portion of limb;
most common in foals;
caused by: malpositioning in utero, excessive joint laxity, hypothyroidism, trauma, overnutrition, defective endochondral ossification
angular limb deformity
85
name 3 categories of joint pathology
1. Degenerative Joint Disease (DJD)
2. Inflammation
3. Growth and development abnormalities
86
# name the joint pathology
destructive disease leading to loss of articular cartilage in one or multiple joints ;
can be primary (idiopathic or age-related) or secondary
degenerative joint disease (DJD)
| (osteoarthritis)
87
name 3 causes of premature degeneration of cartilage
1. direct damage
2. joint instability
3. abnormal forces
88
# name the term
inflammation of the intra-articular structures, incl. synovial membrane
arthritis
89
# name the term
inflammation of the synovial membrane only
synovitis
90
# name the term
an all-encompassing term referring to any joint disease, whether inflammatory or not
arthropathy
91
what 3 things can arthritis be classified based on
1. cause
2. duration
3. nature of exudate
92
name 4 causes of arthritis
1. infectious
2. immune-mediated
3. urate deposits
4. sterile
93
name 4 portals of entry for infectious arthritis
1. navel
2. GIT
3. traumatic inoculation
4. extension from bone or periarticular soft tissue
94
what reaction is non-infectious (immune-mediated) arthritis driven by?
type III hypersensitivity
(Ag/Ab complexes gather in joint space)
95
name the two forms of non-infectious (immune-mediated) arthritis
1. erosive
2. non-erosive
96
# name the abnormality of growth and development
persistent congenital flexure of a joint in conjunction with muscle contraction
arthrogryposis
97
name 4 causes of arthrogryposis
1. inactivity or paralysis in utero
2. spinal dysraphism
3. intrauterine viral infections
4. toxic plants
98
# name the abnormality of growth and development
inherited disease in which joint laxity results in secondary degenerative joint disease;
joint laxity → subluxation → flattening of dorsal rim of acetabulum → modelling of the acetabulum and femoral head
hip dysplasia
99
name 3 contributing factors of hip dysplasia
1. heredity
2. weight
3. over-exercise
100
# name the abnormality of growth and development
a disorder of growth cartilage occurring in growing animals;
focal failure of blood suppy to growing cartilage leads to ischemic necrosis of cartilage;
can lead to delayed endochondral ossification
osteochondrosis
101
name 5 things involved in osteochondrosis, making it multifactorial
1. trauma
2. genes
3. rapid growth
4. ischemia
5. nutrition
102
these dogs are predisposed to degenerative disk change from early age;
nucleus pulposus is replaced by chondroid tissue which mineralizes and fragment;
annulus fibrosus secondarily degenerates
chondrodystrophic dogs
103
in these dogs, degeneration begins in the annulus fibrosus;
there is fibrosis of the nucleus, rather than chondroid degeneration;
middle-aged dogs affected;
thoracolumbar area predisposed
non-chondrodystrophic dogs
