Exam 2 Bone TE Flashcards
Describe cortical bone.
Dense, compact bone
Hard outer layer of bones
Strong and stiff (provides structural support)
What percent of skeletal mass is cortical bone?
80%
Describe trabecular bone?
Spongy porous bone
High surface area, fills the inner layer of most bone
Lightweight and supports metabolic activities
Highly vascularized
What are the four types of bone cells?
Osteoblasts, osteoclasts, osteocytes, osteogenic cells
What are osteoblasts and what is their role?
Mononucleate bone-forming cells
Produce bone matrix (collagen, etc.)
Responsible for mineralization
What are osteoclasts and what is their role?
Multi-nucleate bone-resorbing cells
Breaks down bone tissue and help bone remodeling with calcium release
What are osteocytes?
Osteoblasts trapped in mineralized bone
Mature bone cells
What are osteogenic cells?
Precursor stem cells that differentiate into other cells (osteoblasts)
Progenitors
What are the key signals in bone formation?
BMPs, VEGF, PDGF
What does BMPs do?
Stimulates bone formation
Induces differentiation of MSCs to osteoblasts
What does VEGF do?
Promotes angiogenesis (formation of blood vessels)
Important for delivering nutrients during bone repair
What does PDGF do?
Recruits MSCs and other progenitor cells
Stimulates proliferation and angiogenesis
Name the timeline of bone fracture healing.
Days 0-5: Hematoma
Day 5-7: Soft callus/ unmineralized cartilage
Day 10-16: Fibrous Tissue
Day 16-21: Hard callus/ secondary tissue
Day 21-35: Hard callus/remodeled bone
What are the main types of bone scaffold?
Foams, fibers, gels, mostly polymers, ceramics, and composities
What is bone resorption?
Breakdown of bone by osteoclasts
What is bone formation?
The building of bone by osteoblasts
What is Osteoinductive?
ability to induce bone formation
What is Osteoconductive?
ability to support bone formation, usually through attachment of bone forming cells
What is osteointegration?
Direct structural connection between living bone and implant surface
What are the key bone TE strategies (list)?
Recruiting and controlling SC
Altering the healing niche
