Terminology - Bio 120 - Summer 2010

1. FRACTURES - bones by Beatriz

2. Facts about fracture: A fracture occurs when the bone tissue is subjected to tensile, compressive, or shear forces in excess of its strength. Both the strength of the bone tissue and the nature of the forces acting on bone change from infancy to old age, both normally and as a result of disease. Therefore, the incidence and type of fractures change with age.

4. Woman over the age of 45.Who is at risk?

5. Also spelled callous in osteology, bony and cartilaginous material forming a connecting bridge across a bone fracture during repair. Within one to two weeks after injury, a provisional callus forms, enveloping the fracture site. Osteoblasts, bone-forming cells in the periosteum (the bone layer where new bone is produced), proliferate rapidly, forming collars around the ends of the fracture, which grow toward each other to unite the fragments. The definitive callus forms slowly as the cartilage is resorbed and replaced by bone tissue. Two to three weeks after injury, strong bony extensions join the fractured bone ends. Callus (osteology)

6. A fracture is called simple (closed) when the overlying skin is not broken and the bone is not exposed to the air; it is called compound (open) when the bone is exposed. When a bone weakened by disease breaks from a minor stress, it is termed a pathological fracture. An incomplete, or greenstick, fracture occurs when the bone cracks and bends but does not completely break. Compound fracture (pathology)

7. Fracture of bone in pathology, a break in a bone caused by stress. Certain normal and pathological conditions may predispose bones to fracture. Children have relatively weak bones because of incomplete calcification, and older adults, especially women past menopause, develop osteoporoses, a weakening of bone concomitant with aging. Pathological conditions involving the skeleton, most commonly the spread of cancerto bones, may also cause weak bones. In such cases very minor stresses may produce a fracture. Other factors, such as general health, nutrition, and heredity, also have effects on the liability of bones to fracture and their ability to heal.

8. A severe injury in which both fracture and dislocation take place simultaneously. Frequently, a loose piece of bone remains jammed between the ends of the dislocated bones and may have to be removed surgically before the dislocation can be reduced. Immobilization must be longer than in a simple dislocation to permit healing of the fracture; chances for permanent stiffness or disability are greater than in uncomplicated dislocation or fracture. Fracture-dislocation (pathology)

9. A fracture is called simple (closed) when the overlying skin is not broken and the bone is not exposed to the air; is called compound (open) when the bone is exposed. When a bone weakened by disease breaks from a minor stress, it is termed a pathological fracture. Simple fracture (pathology)

10. Stress fracture (medicine) Bone disease Fractures Fracture sometimes develops slowly rather than suddenly. Fatigue, or stress, fractures occur because the bone tissue is exposed to forces that overwhelm its capacity for structural adaptation. Examples include fracture of the thighbone and fracture of the bones of the foot (march fracture) in soldiers during their initial months of physical.