Connective Tissue Flashcards
Connective Tissue Functions
Connect
Protect
Support
Connective Tissue Components
Made of fibers, cells and ground substance
Fibers
Provide tensile strength
Main types are collagen and elastin
Collagen
Made up of tropocollagen
Cells
Either fixed or migratory
Ground Substance
Made up of water, GAG’s and proteoglycans
GAG’s
Negatively charged and resist pressure
Dense Connective Tissue
Ligament
Tendon
Outer layer of joint capsule
Loose Connective Tissue
Adipose
Areolar tissue
Surrounds blood vessels/nerves
Viscoelastic Material Properties
Time-dependent
Rate-dependent
Hysteresis
Time-Dependent
Longer load = greater deformation
Rate-Dependent
Better resists loads applied more quickly than slow
Hysteresis
Energy dissipates due to internal friction, leading to curve of deformation
Creep Phenomenon
Strain reaches equilibrium over period of time
Stress-Strain Curve
Strain is the deformation of tissue
Stress is the load placed on the tissue
Toe Region
Minimal stress
Elastic Region
Increased stress up to yield point
Elastic limit
Plastic Region
Past the last limit and will have permanent deformation
Failure Point
Complete rupture
Young’s Modulus
How much a substance will deform in response to force
Cortical Bone
Outer perimeter
Resist torsion and bending
Cancellous Bone
Metabolic activity
Highly vascular
Wolff’s Law
Bone is laid down in areas of high stress and resorbed in areas of low stress
Cartilage Zone
Superficial (horizontal collagen) (1)
Transitional zone (arch-like collagen) (2)
Deep zone (perpendicular collagen) (3)
Zone of calcified cartilage (4)
Tendons
Type 1 collagen fibers Oriented in line of tension Transmit muscle force to bones Poor blood supply Myotendinous junction is weakest
Ligaments
Type 1 collagen fibers
Oriented in line of tension
Provide joint stabilization at end range
Bone to bone
Bone Optimal Stimulus
Loading along axis of bone
Cartilage Optimal Stimulus
Intermittent compression and decompression
Ligaments/Tendons
Tensile stress in the line of fiber orientation
Aging on Connective Tissue
Decreased water content, elasticity, maximal strength and adaptability
Diabetes on Connective Tissue
Increased cross-linkage of fibers (greater stiffness and risk for damage)
Immobilization on Connective Tissue
Osteoporosis Decrease water content Atrophy of cartilage Atrophy at MTJ (dec tendon strength) Atrophy/disorganization of ligament fiber arrangement
