Pathology Flashcards
fractures
injury to bone causing a break or disruption in the continuity of the bone architecture.
pathologic fracture
diseased or weakened bone undergoing mechanical stress that fractures but would not fracture if it were a normal bone
stress fractures
overuse or repetitive smaller mechanical force that fractures bone (even in physiologically normal bone)
Fracture Repair
- clot forms
- soft callus forms
- cartilage and woven bone form bony callus
- lamellar bone produced by remodeling bony callus.
Healing Disruption
malalignment, poor immobilization, infection, malnutrition.
closed fracture
skin in tact, also known as simple
open fracture
bone fragments push out through the skin, also known as compound
compression fracture
typically affect vertebral bodies, also known as buckle
Organic Components of Bone
collagen
inorganic components of bone
calcium, and phosphorus make up Hydroxyapatite
Cortical (compact) Bone
80% of skeletal mass
provides structural support
Cancellous (spongy, trabecular, medullary) Bone
20% of skeletal mass
covered in bone forming cells (osteoblasts)
provides space for bone marrow (hematopoiesis)
bone turnover manifests here
Bone Matrix
10%- composed of cells
60%- hydroxyapatite (calcium and phosphorus)
30%- organic matrix (88% collagen, 10% osteocalcin and osteopontin and sialaprotein (recognized by integrins and anchors cells), and 1-2% lipids and glycosaminoglycans)
osteoblast
forms bone matrix (build bone)
osteocyte
maintains bone tissue (sandwiched in haversian canals) communicate with each other, absorbs Calcium
