Skeleton & Joints Flashcards
What are cartilage and bone made of?
Cells
Fibre
Ground substance
Cartilage vs bone
Cartilage is more flexible than bone - can withstand compression forces
Cartilage has no blood supply - it is avascular
Why does cartilage not need a blood supply?
Cartilage has a high water content - it can rely on diffusion of nutrients
3 types of cartilage
Elastic cartilage - elastic fibres
Fibrocartilage - collagen fibres
Hyaline cartilage - cartilage with fluid
2 types of cartilage growth
Appositional growth - chondroblasts differentiate into chondrocytes
Interstitial growth - proliferation and hypertrophy of existing chondrocytes (replicated cells stay clustered together)
Majority of bone matrix
Made of hydroxyapatite (compound of calcium phosphate)
Bone calcification
Extra cellular matrix is calcified - goes from osteoid to bone
Structure of bone
Shaft - primary centre of ostification
Epiphysis - secondary centre of ostification
Yellow marrow - contains mesenchymal stem cells
Red marrow - where RBCs are made by haemopoiesis
Different types of bone cells
Osteogenic/osteoprogenitor cell - stem cell
Osteoblast - forms bone matrix
Osteocyte - maintains bone tissue
Osteoclast - resorbs bone
How many bones in adults? Newborns?
Adult - 206
Newborn - roughly 300
Functions of the skeleton
Provide rigid framework for muscle attachment
Allows movement
Protects organs
Storage reservoir of calcium and phosphate
Production of blood cells
Types of bone shapes
Long
Short
Flat
Irregular
Sesamoid
Bone development
1 - Originate directly from soft connective tissue (intramembranous ossification)
2 - Develop from cartilage (endochondral ossification)
What is missing from bones formed by intramembranous ossification?
Hyaline cartilage
Types of joints
Fibrous joints
Cartilaginous joints
Synovial joints
