Bone cells, bone formation and fracture repair Flashcards
What are the 4 major bone cells? (excluding marrow)
- Osteoblasts
- Osteocytes
- Osteoclasts
- Osteoprogenitor cells
What are Haversian canals?
tiny, interconnecting longitudinal channels in bone tissue through which blood vessels, nerve fibers, and lymphatic vessels pass.
Located at the center of osteons
Marrow:
- _____- responsible for hematopoiesis (blood cell production) contains mature and immature blood cells, including red blood cells, white blood cells, and stem cells
- _____- primarily adipocytes but can become other marrow if anemic conditions arise
- Red marrow
2. Yellow marrow
When bone formation occurs within connective tissue the process is referred to as _____, this is generally how flat bones are formed and bone repair occurs.
intramembranous ossification
When pre-existing cartilage is converted to bone the process is termed, _____, this occurs at growth plates of long bones.
endochondral ossification
Bone growth can only occur at two specialized sites:
1.
2.
- on the surface, periosteal layer
2. specialized epiphyseal plates
_____ are instrumental in the bone resorption process
osteoclasts
what are the four key steps to fracture repair?
- Hematoma formation
- Fibrocartilaginous callus formation
- Bony callus formation
- Bone remodeling
During fracture the tearing of blood vessels (small and Large) result in the formation of a mass clotted blood (hematoma)
Bone cells begin to die, the site undergoes the inflammatory response
Hematoma formation.
The fibroblasts release collagen to span the break, the osteoblasts begin spongy formation (intramembranous)
Fibrocartilaginous callus formation
Bone trabeculae begin to appear as osteoblasts convert the fibrocartilaginous callus into spongy or woven bone.
Bony callus formation
Excess materials comprising the bony callus are resorbed and replaced from the periosteal and the endosteal spaces
Dense compact bone is re-formed, including alignment of the Haversian Canals
Bone Remodeling
