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Flashcards in Response of bone to injury, use, aging Deck (17)
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Differentiate between a pressure epiphysis and a traction epiphysis

Pressure epiphysis: located at the ends of long bones, serves as articulation for joints and contributes to longitudinal growth of bone

Traction epiphysis: centers of ossification, site of tendon or ligament attachments. contributes to shape but not length of bone
aka apophysis


List the three zones of the growth plate

reserve zone
proliferative zone
hypertrophic zone


Describe the reserve zone of the growth plate

Closest to the epiphysis, cells produce and store the cartilaginous matrix. Blood
supply is poor, cells do not actively divide.


Describe the proliferative zone of the growth plate

- cells synthesize extracellular matrix, actively divide, and are stacked in columns to produce longitudinal growth.
- best blood supply, for cellular nutrition and hormonal signals necessary for growth plate function.


Describe the hypertrophic zone of the growth plate

- prepares the matrix for calcification and initiates calcification
- anaerobic metabolism


Injuries to the _____ in immature people are never minor

physis/ growth plate


In response to stress, bone remodels and forms bone best suited for ________

weight bearing

Wolff's law: bone is deposited in areas best positioned to resist stress/ loads


Physeal fracture types III, IV, and IV are most likely to disturb ____

growth, poorer prognosis


Differentiate complete growth arrest vs partial growth arrest with a physeal fracture

complete growth arrest--> shortened extremity
partial growth arrest --> angular deformity +/- shortening


Describe primary bone healing

- rigid internal fixation of fracture
- primarily cortical healing
- no callus formation
- cutting cones lead the vascular ingrowth and eventually osteoblastic bone deposition
- very slow


Describe secondary bone healing

- some motion at the fracture site during healing
- callus formation stabilizes the fracture site
most common form of healing


______ develop due to repetitive micro trauma that eventually exceeds bone's ability to repair

stress fractures


X rays will often be _____ at initial clinical evaluation for stress fractures


diagnosis can be made on repeat radiographs when callus formation is seen


___ peaks by age 30, then eventually starts to decline after the 5th decade

bone mass


Describe changes in bone mass in women after menopause

Both men and women lose cortical bone mass at a similar rate, however women after menopause have a more rapid decline in trabecular bone mass than men.


Differentiate osteopenia, osteomalacia, and osteoporosis

osteopenia: general term for decreased bone density on radiographs

osteomalacia: impaired mineralization of bone matrix, problem of bone quality not quantity

osteoporosis: decreased density of bone, problem of bone quantity not quality


What can cause osteomalacia?

nutritional deficiencies, GI absorption defects, renal tubular defects, toxins