ligaments, tendons and muscle Flashcards
Draw a load-elongation curve for ligaments and tendons?
- toe region - uncrimping of fibres
- progressive failure of the fibres
- minimal to no plastic zone
axis:
* load = n
* elongation = mm
what is the difference between ligaments and tendons?
5 main differences between ligaments and tendons:
* structure
* composition
* blood supply
* insertion site
* function
Structure
Both have type 1 collagen fibres but arranged differently:
* Ligament - layered fibres , less parallel - strength in different planes instead of one plane
* Tendon - parallel fibres - good at resisting stretch - high tensile strength
Composition
- Tendons: collagen high
- Ligaments: more elastin
Blood supply
Tendons - sheathed or unsheathed
* sheathed - vinculae diffusion - flexor tendons
* unsheathed - paratenon - more vascular - achilles tendon
Ligaments -bone
Insertion
* ligaments - insert directly onto the bone
* tendon - indirect via 4 transition zones
zone 1 - tendon tissue - tenocytes
zone 2 - uncalcified fibrocartilage - chondrocytes
zone 3 - calcified fibrocartilage - chondrocytes
zone 4 - subchondral bone - osteocytes
sharpey fibres cross all 4 zones
Function
Ligaments
* insert from bone to bone
* augment stability and proprioception
Tendon
* attach muscle to bone to transmit load
what is the structure and composition of tendons?
what is the structure and composition of ligaments?
-
Tendon healing
Haematoma phase
* tendon ruptures, activation of coagulation cascade and lots of fibrin
Inflammatory (proliferative) phase
* proliferation of fibroblasts
* increase in type 3 collagen - early movement reduces type 3 laid down
* macrophage activity - remove necrotic debris
Remodelling (consolidation) phase
* type III collagen converted into type 1 collagen
repair is weakest at 7-10 days
Tell me about the structure of muscle?
Why is tensioning muscle important for its function?
