musculoskeletal system

Question 1

osteoblasts are derived from what?

Answer 1

mesenchymal “osteoprogenitor” cells

Question 2

osteoclasts are derived from what?

Answer 2

granulocyte/moncyte

Question 3

primary idiopathic osteoporosis =

Answer 3

senile or postmenopausal

–bone loss = 2 phases: 1st= slow & 2nd = woman speed up

Question 4

secondary osteoporosis =

Answer 4

• -low dietary calcium/poor assimilation of calcium
• -endocrine disease = hypogonadism, cushing’s, hyperparathyroidism, hypopituitarism
• -pregnancy
• -malabsorption//malnutrition

Question 5

osteoporosis morphology

Answer 5

• -greatest bone loss is in trabecular bone

- -vertebral bodies, proximal femur & distal radius are most commonly affected

Question 6

osteoporosis morphology

in woman the vertebral bodies are progressively disabled

Answer 6

a) Cod fish vertebrae
b) Schmorl’s nodes
c) Crush fractures

Question 7

Von Recklinghausen’s Disease of Bone

Answer 7

advanced hyperparathyroidism

• -month-eaten X-rays
• -“brown tumors”
• -loss of lamina dura

Question 8

paget’s disease

Answer 8

reabsorbed bone looks “tile-like mosaic”
Stages = hot –> mixed –> cold
–monostotic = 15% ~tibia
–polyostotic = 85%

Question 9

osteomyelitis

Answer 9

infection of marrow

• -pyogenic osteomyelitis
  
  • -STAPH. aureus = adult
  • -H. influenza & B. hemolytic strep = child
• -severe = necrotic sequestrum surrounded by an involucrum
• -Brodie’s abscess = small intraosseous abscesses that are “walled off” (tibia & long bones)

Question 10

tuberculous osteomyelitis

Answer 10

• -grow nodules most common in lungs

- -locations = in spine: POTT’S DISEASE

Question 11

malignant tumors (primary & secondary)

Answer 11

primary = mesenchymal cells
–chondrosarcoma, Ewing’s sarcoma, osteosarcoma**, malignant giant cell

secondary = carcinomas

Question 12

osteosarcoma

Answer 12

most common primary bone
Primary = 75% = age 10-25
morphology = codman’s triangle = zone of reactice bone that forms at angle of periosteal reflection

Question 13

chondrosarcoma

Answer 13

• large bulky masses

- pelvis most common

Question 14

Ewing’s sarcoma

Answer 14

highlt malignany & typically in marrow

commonly associated w/ fever, swelling, anemia

Question 15

Giant cell tumor (osteoclastoma)

Answer 15

clin features = soap bubble appearance

• 20-55 age
• majority are benign

Question 16

Duchenne (muscular dystrophy)

Answer 16

X-linked - pelvis & legs
fatal 2-3yrs
mutation in the gene which produces dystrophin

*becker = similar but mild form

Question 17

facioscapulohumeral (muscular dystrophy)

Answer 17

autosomal dominant
mild severity
face & shoulders

Question 18

limb girdle

Answer 18

autosomal recessive
moderate severity
pelvis & shoulders

Question 19

myasthenia gravis

Answer 19

block at the myoneural junction (aka- antibodies stop ACh)

-thymic hyperplasia

Question 20

osteopgenesis imperfecta

Answer 20

“brittle bone disease”

• -osteopenia =thinning of bone
• -blue sclera -choroid shows thru
• -hearing loss
• -small teeth

Question 21

osteppetrosis

Answer 21

“marble bones” aka-Albers-Schonberg
–overgrowth or cortex & medullary cavity

• -malignant pattern = autosomal recessive condition
• -adult pattern = milder autosomal dominant

Question 22

Achondroplasia

Answer 22

abnormality in epiphyseal plates = dwarfism

Question 23

marfan’s syndrome

Answer 23

congenital disorder = CT = changes in skeleton, eyes, and cardiovascular system
–due to defect in fibrillin (chromosome 15)

Question 24

rhabdomyolysis =

Answer 24

rupture of skeletal muscle