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
Fibrous joint
Found where there is little movement between bones
Bones are connected by fibrous tissue
Types of fibrous joints
Sutures - serrated, squamous, plane
Syndesmoses - bound by ligaments
Gomphoses - peg and socket
Types of cartilaginous joints
Primary - bone segments separated by hyaline cartilage
Secondary - separated by fibro cartilage
Where are primary cartilaginous joints found?
Growing skeleton
1st sternocostal joint
Where are secondary cartilaginous joints found?
In the midline of the body
Bursa
When capsule is breached by the synovial membrane
Gives synovial cushion to structures surrounding the joint
What does joint stability depend on?
Articular shape
Strength of capsule
Ligaments
Muscle
Tendons
Types of movement in joints
Saddle joint
Ball and socket joint
Pivot joint
Hinge joint
Gliding joint
Ellipsoid/condyloid joint
