Lecture 4: Connective Tissue Part 2 Flashcards
Cartilage is ___, ___ and more ___ than bone.
Stronger, lighter, flexible.
What are the three components of cartilage?
- Cells
- Fibres
- Ground Substance
What produces the extracellular matrix?
The chrondoblasts and chrondocytes.
What structure surrounds cartilage (except articular cartilage)?
The perichondrium which is dense irregular connective tissue.
How does cartilage gain nutrients considering is lacks all vessels?
Through diffusion.
What are the two cell types found in cartilage?
Chondroblasts (stem cells) and chrondocytes (mature blasts).
Where are chrondocytes located and what is their function?
Located in isogenic groups surrounded by ECM. The function is to secrete and maintain the ECM.
Where are the chrondoblasts located and what is their function?
Derived from mesenchymal cells in the perichondrium. Their function is to secrete the ECM of cartilage.
What are the four layers in this structure of cartilage?
Perichondrium, cartilage, loose connective tissue, respiratory epithelium (top to bottom).
What are the two types of growth patterns of cartilage?
Interstitial and appositional.
What is interstitial growth?
The division of chondrocytes by mitosis to make more matrix.
What is appositional growth?
Where mesenchymal cells in the perichondrium differentiate into chondroblasts.
What is the perichondrium?
The dense irregular tissue that surrounds cartilage. (All but articular cartilage).
What are the cells of the perichondrium called?
Condrogenic cells.
What are the three types of cartilage?
- Hyaline cartilage
- Fibrocartilage
- Elastic cartilage
All contain chondrocytes but differences arise in the ECM.
What is the most common type of cartilage and what is its main function?
The function of hyaline cartilage is to resist compressive forces due to high water content.
What type of cartilage is this?
What type of cartilage is this?
What type of cartilage is this? Insert histology of elastic cartilage ppt. pg. 25.
Elastic cartilage.
The ECM of elastic cartilage contains ___ and ___.
Collagen (type II) and elastin fibres.
Cartilage is avascular and thus gains nutrients via ___ only.
Diffusion.
How is cartilage repaired?
The differentiation of cells from the perichondrium.
Why is articular cartilage difficult to repair?
There is no perichondrium.
What are the three regions of a long bone?
- Proximal epiphysis
- Diaphysis
- Distal epiphysis
What are the three components of bone and what gives bones rigidity?
- Cells
- Fibres
- Ground Substance
The rigidity is formed from the mineralisation of the ECM.
What are the four types of bone cells?
- Osteoprogenitor cells (stem cells)
- Osteoblasts (bone forming cells)
- Osteocytes
- Osteoclasts
What are the three main functions of bone?
- Support
- Protection
- Calcium homeostasis
Bones exist in what two forms?
- Woven (immature)
- Lamellar (mature) – is compact and spongy
Where is the periosteum (tough connective tissue layer) located?
The outermost layer of the bone, surrounding the other structures.
What type of immature bone has random organisation of collagen fibres?
Woven bone.
What type of bone is dense and organised with osteons and a lateral canal?
Compact bone (fibres and matrix create strength and rigidity).
What shape are osteons and where do they run from?
Osteons are cylindrical and run the length of compact bone.
What is the function of an osteon?
The function is to provide a canal for blood vessels, nerves and lymphatics while resisting vertical compression.
How do blood vessels supply osteons?
Through lateral canals.
Where do the arteries come from that supply the bone?
The periosteum.
