Ch 8 PT 3

Question 1

ossification (osteogenesis)

Answer 1

formation and development of bone connective tissue; begins in the embryo and continues through adolescence

Question 2

bone remodeling

Answer 2

occurs at periosteal and endosteal surfaces of a bone; continual addition (deposition) of new bone tissue and removal (resorption) of old tissue. caused by detection of mechanical stress.

Question 3

hormones that affect bone growth

Answer 3

somatotropin (growth hormone), stimulates liver to produce somatomedin/IGF (insulin-like growth factor) which directly stimulates the growth plate; thyroid hormone increases BMR for balance; sex hormones increase rate of growth.

serotonin and glucocorticoids (steroid hormones) inhibit growth

Question 4

hormones that regulate blood calcium levels

Answer 4

PTH, calcitriol (synthesized from calcidiol by the kidneys; active form of D3), calcitonin

Question 5

osteopenia

Answer 5

bone loses calcium and demineralizes; bones of the skeleton become thinner and weaker, resulting in insufficient ossification

Question 6

osteoporosis

Answer 6

a condition characterized by reduction in bone mass sufficient to compromise normal function; decrease in hormone levels with aging contributes to reduction in bone mass

Question 7

fracture

Answer 7

break in a bone

Question 8

stress fracture

Answer 8

thin break caused by increased physical activity in which the bone experiences repetitive loads

Question 9

pathologic fracture

Answer 9

usually occurs in bone that has been weakened by disease

Question 10

simple fracture

Answer 10

“closed”; the broken bone does not penetrate the skin. healing takes 2-3 months.

Question 11

compound fracture

Answer 11

“open”; one or both ends of the broken bone pierce the overlying skin. Healing typically takes longer than 3 months.

Question 12

4 basic steps of fracture repair

Answer 12

• fracture hematoma forms
• fibrocartilaginous callous forms
• hard (bony) callous forms
• bone is remodeled