Microstructure and Ultra Structure of Ligaments and Tendons Flashcards
what are the cervical spine ligaments?
Anterior and Posterior Atlanto-Occipital Membranes
Apical Ligament of Dens
Alar Ligaments
Transverse Atlantic Ligament
Cruciate Ligament of the Atlas
Tectorial Membrane of Atlanto-Axial joint
Nuchal Ligament
what are the major molecular components of both tendons and ligaments?
collagens
what is collagen?
a fibrous protein with high tensile strength.
what are the 3 types of collagen?
procollagen
tropocollagen
growing fibril
The structural hierarchy of ligaments and tendons is made up of what?
fibres, fibrils, subfibrils, microfibrils and tropocollagen but also contain water, proteoglycans and several glycoproteins.
fibroblasts are what?
the biological cells that produce the ligament or tendon via the formation of collagen.
skeletal ligaments are what and do what?
soft, densely-packed, fibrous bands of collagenous connective tissue which connects two bones, cartilage or holds together a joint
what is a ligaments function?
to guide normal joint motion when a tensile load is applied, passively maintain stability of joints and restrict abnormal or excessive joint movement.
when are the fibres recruited in a ligament?
as the joint moves
what are tendons?
soft, fibrous bands of connective tissue that connect muscle to bone
tendons are composed of what?
collagen
tendons are passive or unpassive?
passive
are tendons elastic or inelastic?
inelastic
what is the main function of tendons?
to transfer muscle generated tensile force to the bony skeleton, facilitating movement around a joint.
tendons act as what?
a mechanical pulley
what are the secondary functions of tendons?
maintain posture, stability and provide motor control.
does the arrangement of collagen fibres differ between tendon and ligament?
yes
how are ligaments organised?
in a dense but random/loose-packed network.
how are tendons organised?
highly ordered, linearly packed arrangement of bundles almost parallel to the long axis of the tendon in line with the muscle.
what are ligaments and tendons composed of ?
of fibres oriented in a parallel manner
tendons can handle what during activity?
handle higher unidirectional (uniaxial) tensile loads
ligaments handle what during activity?
generally sustain tensile loads in a predominant direction but also bear smaller tensile loads in other directions, i.e. they are anisotropic.
tendons have how much protein?
very little- type III
ligaments have how much protein?
higher ratio of Type III collagen to Type I collagen.
what are ligaments mechanical porperties?
provide it with not only the flexibility but also the tensile properties to resist force.
how much of ligaments is composed of water?
65%- 70%
type I collagen makes up what of ligaments and is responsible for what?
70-80% of dry weight, tenisle strength
type III collagen makes up what of ligaments total wight?
8% dry weight
type V collagen makes up what of ligaments?
12% dry weight
Variations in the concentrations of these basic constituents in ligaments lead to what?
different mechanical behaviors suitable for their respective functions.
The differences in collagen concentrations arise due to what?
differences in the fibroblasts and their gene expression such as reticular cells.
The ligamenta flava consist mostly of what?
dense elastic fibers
supraspinous and interspinous ligaments are predominantly made up of what?
collagenous correlating with their difference in function
The hierarchical structure of tendon and its functional properties are determined what?
by the collagens present, as well as their supramolecular organization.
load refers to what?
external force applied to the collagen.
stress refers to what?
to the amount of resistance within the collagen to the load.
strain refers to what?
is the amount of deformation that occurs in the collagen because of the load.
crimp is what?
is the waviness of the fibrils that make up the fascicles.
how many regions are ther in a stress strain curve?
3