TENDONS Flashcards
what are the types of connective tissue
- muscle
2.bone - tendons - muscle to bone
- cartilage
- ligaments -connect bone to cone
what are the 2 types of musculoskeletal injuries(bone, muscle, tendons and ligaments)
- acute onset injuries- from a single overuse event
- chronic overuse injuries - repetitive overuse
what is the point of union between muscle and tendon
the myotendinous junction
what is the point of union between muscle and bone
the osteotendinous junction
what are the 2 properties of tendons
they are viscous and elastic
what are features of the viscoelastic tendon material
- hysteresis
- rate dependence
- creep
- load relaxation
what is hysteresis
this is when the loading an unloading of a tendon leads to energy loss as heat
what is rate dependence
this is when the faster we load a tendon leads to greater stress and strain compared to when it is loaded slower
what is load relaxation
this is when a constant load is applied to tendons kept at constant length we see a decrease in the force in the tendons
what is creep
when a constant load is applied to tendons we see their length deform over time
explain the stages of the tendon stress(load) strain(elongation) curve
1.the first step is the toe phase where we see uncrimpling of the collagen fibres
2. linear phase where we see the collagen backbone straightening aswell
3. failure where we see the fibres sliding past one another and crosslinks breaking and so the the tendons fail
=rupture if not healed properly
what is the structure of a tendon
- collagen molecule(proteins ie type 1)
- fibril-protein collagen molecules come together
- fibre-fibrils come together
- fascicle -fibers come together
5.tendon-fascicles come together
what is the smallest structural unit of collagen
the collagen fibril
what are the collagen proteins made of
alpha chain triple helices
-these are when 3 alpha chains come together to form a helix
-each alpha chain is made up of triplet repeats of GLY-X-Y
-X is usually lysine or proline
-Y is usually hydroxylysine or hydroxyproline
-the triple helices are glycosylated
what are the types of fibrillar collagens
- type 1 collagen - 2a 1 and 1a2 chains
-most abundant type
-heterotrimer
-confers rigidity - type 11 collagen- 3a1 chains
-homotrimer
-most common in cartilage
3.type 111 collagen
- 3a1 chains
-often found with type 1
-confers elasticity