Connective Tissue formation - week 17 Flashcards
What four components are there in connective tissue?
Cartilage, bone tendon, skin
What is the role of proteoglycans in connective tissue?
Important for mechanical properties of connective tissue
holds water in tissues
viscoelastic properties
interacts with cells, cytokines and collagen
What is aggrecan and its role in connective tissue?
Forms huge multimetric aggregates in cartilage
Draws water into tissue so enables cartilage to resist compression
What is the pathophys of osteoarthritis?
Altered joint mechanics
Breakdown of aggrecan and type II collagen
impairs mechanical properties of cartilage
causes pain
What are elastin fibres?
contain elastin, fibrillin 1,2,3, fibulins 4,5 and matrix associated glycoproteins
has structural (stretching of walls) and regulatory role
What is collagen?
Main structural component of connective tissue
How is collagen arranged from molecular to whole structure?
polypeptide chain (triple helix)
Collagen molecule
microfibril
fibril
fibre
What enables the longevity of collagen?
V stable and v slowly turned over
How many polypeptides are intertwined for each molecule of fibrillar collagen?
3 alpha chains (triple helix)
How does Vit C cause reduced collagen hydroxylation?
The reduced hydroxylation of proline in collagen weakens the collagen triple helix
What is the clinical diagnosis for Vit C defiiency and weakened collagen fibrils?
Scurvy
Symptoms of scurvy?
Bleeding gums
Loss of teeth
Skin lesions, bruises
Poor wound healing
Joint pain and weakness
How does connective tissue organisation vary?
different collagen composition depending on its location (skin, bone, tendon, cartilage)
What type of collagen and structure is in bone?
Type 1 collagen
forms lamellae
What type of collagen and structure is it in tendons?
Type 1 collagen
Forms fibrils in parallel bundles (allowing its strength)
What is unique about the enthesis of tendons regarding matrix organisation and composition?
Enthesis structure varies along its length
What is the pathophys of tendinopathy?
loss of collagen fibril organisation and reduced fibril diameter
changes collagen content
often affects the enthesis
