11. Histology of Bone & Cartilage Flashcards
Label this (bone).
What are the 2 types of bone?
- Other names for lamellar bone?
- Other names for woven bone?
- Where do each lie in a bone?
- Functions of each?
Types of Bone
Lamellar Bone (80% skeletal weight)
- Also known as Cortical, Compact, or Dense bone
- Weight bearing tissue of long bones
- Mature
Woven Bone
- Also known as Cancellous, Trabecular or Spongy bone
- Supportive, scaffolding structure of inner bone
- In healing bone is the immature precursor
What are the 4 cells of bone?
- What is the embryological origin of Osteoprogenitor cells?
Label the bone cells here.
Label the components of bone.
What is the Bone Matrix composed of?
Bone Matrix Composition
-
Inorganic/Mineral component
- 60 to 70% mineralized component
- Microcrystalline calcium phosphate (hydroxyapatite)
- Traces of sodium, magnesium, fluoride etc.
-
Organic component
- Type I collagen
- Glycosaminoglycans
What are 5 functions of bone?
Bone Functions
- Support
- Protection
- Locomotion (with muscles)
- Haematopoiesis (bone marrow)
- Calcium and phosphorus storage
How does bone develop?
Bone Development
- In the embryo formed from a cartilaginous precursor (most long bones)
- Precursor - osteoid - replaced by mineralized bone as it grows and is vascularized
What are osteoids?
What is Lamellar/Compact/Cortical/Dense Bone?
- What is their unit of structure?
- What surrounds it?
- What lines marrow cavity?
Lamellar/Cortical/Compact/Dense Bone
- Structure from transformation of osteoid
- Collagen aligned into sheets of parallel fibrils
- Composed of cylinders (along the long axis) known as osteons or Haversian systems
- Outside surrounded by circumferential lamellae and then periosteum
- Endosteum lines marrow cavity
Describe the osteon of lamellar bone.
Osteon of Lamellar Bone
- Layered cylinders of collagen
- Lacunae of osteocytes between each layer(lamella)
- Canaliculae radiate from each lacuna and house osteocyte cellular processes
- Central - Haversian canal contains neurovascular components
Label this image of bone.
Which cells can be seen here residing in the canaliculi of cortical bone?
What do osteocytes look like at different life stages?
What is Woven/Spongy/Cancellous/Trabecular Bone?
- Where is it found?
- What is it oriented to?
- What is it lined by?
Woven (Spongy, Cancellous, Trabecular) Bone
Within core of long bones
Collagen runs in various directions
Oriented to mechanical loads & stresses acting on the bone
Lined by osteoblasts
Where is the lamellar bone?
Where is the cancellous bone?
How old is this bone?
How can you tell?
What kind of bone is this?
What is Cartilage?
- Can it regenerate?
- Blood supply?
- Where does it receive its nutrients from?
What is happening at the mark pointed to by the arrow?
- What part of bone does it form?
Cartiliage = CT
- Does not regenerate
- Is avascular (no blood supply)
- Nutrients by diffusion from perichondrium & synovial fluid
- Forms the bone growth plate
– Also known as the epiphyseal plate
Label this.
What are 3 functions of cartilage?
Cartilage Functions
- Frictionless surface for smooth movement
- Shock absorption - Deformable gel (80% water)
- Resists mechanical stress
What is the Structure of Cartilage (Cells & Matrix)?
Cartilage Structure
Cells
- Chondroblasts - Derived from mesenchymal chondrogenic cells of the perichondrium
- Chondrocytes - Sit in their own lacunae, arranged according to type of cartilage & Secrete cartilage matrix
-
Perichondrium
• Capsule of mesenchymal cells
• Vascular supply which feeds cartilage
Matrix (gel-like)
- Glycosaminoglycans (GAGs)
- Hyaluronic acid, chondroitin & keratan sulphates which are aggregated with collagen fibrils
- Proteoglycans
- Collagen (some water-bound here too)
- Hydrated (between 60 to 78% water) bound to negatively charged GAGs
Describe the zones of cartilage growth.
What are the 3 types of cartilage?
- What type of collagen are each composed of?
- Which is strongest?
- Where are they each found?
- Macroscopic/Microscopic appearances?
- Presence of perichondrium?
Types of Cartilage
1 - Hyaline (means glassy) = Type II collagen
2 - Elastic - more pliable = Type II collagen + Elastin
3 - Fibrocartilage - withstands strong tensile forces = Type I collagen = Structured array of collagen and chondrocytes
Label this.
What type of cartilage is this?
What kind of cartilage is this?
= Fibrocartilage
What are Joints?
- What are the 3 types of joints classified by structure and function?
- What is the binding material of each joint type?
- Which of these joints has a cavity?
- Examples of each
Joints
- Defined as connections between any rigid component parts in the skeleton
- Three types (structural classification)
- Fibrous = Synarthoroses (immovable)
- Cartilaginous = Amphiarthoroses (slightly movable)
- Synovial = Diarthoses (freely moveable)
Label this.
Which type of cartilage forms intevertebral discs?
What are the features of a Synovial joint?
Synovial Joint
- Cartilage/mineralized cartilage/subchondral bone
- Synovial Membrane(synoviocytes)
- Synovial fluid
- Peri-chondrium or peri-osteum
- Joint Capsule
Label this.