Bone development Flashcards
what are the different layers of the bone?
- periosteum
- compact or dense tissue
- spongy or cancellous tissue
- bone marrow
What are the functions of osteoclasts?
- bone resorption
- phagocytosis
- antigen representation
- immune modulation
- T cell activation
What 3 fates do osteoblasts have after bone formation?
- flatten and remain quiescent lining cells at the bone surface
- die by apoptosis
- become surrounded by bone matrix, that calcifies trapping the cells. results in lacunae
What do osteocytes do?
they maintain bone tissue by controlling mineral and calcium content. secrete sclerostin to activate or inhibit osteoclasts.
what type of cartilage do we have?
- hyalin cartilage
- elastic cartilage
- fibrocartilage
what is the function of hyalin cartilage?
lines the joints and caps, reduces friction
what is the function of elastic cartilage
most flexible cartilage, supports parts of your body that need to bend and move to function
what is the function of fibrocartilage
tough cartilage, made of thick fibers, holds body parts into place and absorbs impact.
what are the 3 zones of hyalin cartilage?
- superficial zone > smooth contour, highest collagen content of all zones
- middle zone > collagen fibrils are thicker and align loosely, not parallel to surface
- deep zone > highest proportion proteoglycan, lowest concentration water. chondrocytes arranged in columnar fashion
What do the somites generate in development?
the axial skeleton
what does the cranial neural crest generate in development?
the branchial arche
What 2 processes are used to develop different parts of the skeleton?
- intramembranous ossification
- endochondral ossification
What is intramembranous ossification?
osteoblasts produces bone within connective tissue membrane.
what is endochondral ossification?
Production of bone within cartilage scaffolds, arranged in zones, gradually replaced by bone.
What are the 4 stages of fracture repair?
- hematoma formation
- fibrocartilaginous callus formation
- bony callus formation
- bone remodelling