Post on 29-Dec-2015
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INJURY AND REPAIR
Fracture—any crack or break in bone Repair: 4 months to over 1 year Fracture hematoma forms Large blood clot Closes off injured blood vessels Periosteum and endosteum cells divide New cells move to fracture zone Produce hyaline cartilage Spongy bone replaces hyaline cartilage
(takes long time) Compact bone replaces spongy bone
TYPES CONT…
Transverse Break along a long axis Spiral Twisting along length of bone Comminuted Shatter into fragments
AGING
Become thinner and weaker Osteopenia—inadequate ossification 30-40: Reduction in bone mass Osteoblasts decrease Women lose 8% of bone mass/decade Men lose 3%/decade
OSTEOPOROSIS
Reduction in bone mass past normal Sex hormones help maintain bone mass Over 45: 29% of females and 18% of males have
osteoporosis In females menopause causes decreased
estrogen Bones break easily and do not heal well Estrogen supplements, diet high in calcium
and exercise slow the disease
SKELETAL DIVISION
206 Bones Axial Skeleton (80 Bones) Skull Thoracic Cage (ribs) Vertebral Column Appendicular Skeleton Pectoral and pelvic girdles Arms and legs