Lesson 8 - Connective Tissue Adaptations to Exercise Flashcards
What is the function of connective tissue?
- maintain anatomical form and structure
insulation - energy reserve
- facilitate blood flow
What are the components of connective tissue?
- cells
- fibers
- ground substance
Which components of connective tissue are part of the extracellular matrix?
fibers and ground substance
What kind of fibers make up connective tissue?
- collagen
- elastin
- reticular
What is collagen fiber?
a strong protein with high tensile strength
What is elastin fiber?
an elastic protein with the ability to stretch and recoil
What is reticular fiber?
a short, fine, mesh network of fiber used for holding structures in place
What is ground substance?
gel like substance
Which connective tissues have high blood supply?
vascular tissue, adipose tissue, bone
Which connective tissues have low blood supply?
cartilage, ligaments, tendons
What is stiffness?
extent to which an object resists deformation in response to an applied force
What is Young’s modulus?
stress/strain curve
What is stress?
force or load
What is strain?
change in length
Which connective tissue has high Young’s modulus (stress/strain)?
tendon, ligaments, cartilage
Which connective tissue has a high Young’s modulus?
bone = does not deform easily
What does a tendon allow?
transmission of muscle forces to bones and joints
How does a tendon respond to exercise?
- increase stiffness
How does a tendon increase in stiffness in response to exercise?
increased collagen synthesis leading to changes in tendon material and morphology
What kind of load is most effective to elicit tendon adaptation?
high loads
What is tendon dependent on?
mechanical load
How many weeks of interventions are beneficial for tendon adaptation?
more than 12 weeks
Does contraction type (iso, ecc, con) matter in tendon adaptions?
no, insignificant
What is the role of a ligament?
connect bone to bone for stability
Which connective tissue are ligaments most similar to?
tendons
What is a ligaments response to exercise?
not much evidence on effects but it is suspected they have a similar response to tendon with increased metabolism dn collagen generation/turnover
What is a ligaments response to immobilization?
- loss of collagen tissue
- decline in tissue repair/healing process
What are the several types of cartilage?
- elastic
- hyaline (joints)
- fibrocartilage (cushioning and resists compression)
How does low vascularization affect cartilage?
leads to long healing time
What are the biomechanical properties of cartilage?
- permeability
- viscoelasticity
What is viscoelasticity?
- time dependent response of a material to constant load or deformation
What is stretch relaxation?
decreased tensile force/stress to a given stretch/strain
What is creep?
increased tissue lengthening (strain) to a constant force (stress)
What is cartilage response to exercise?
- thickness declines with static loading
- during dynamic loading, thickness decreases following load onset then remains stable during remaining cycles of loading
How long does it take for linear return to baseline for cartilage after exercise?
90 minutes after exercise
What is the function of cartilage?
not to absorb energy through deformation but equalize load distribution
What is cartilage response to prolonged unloading?
- reduced thickness
- recovery appears possible with reloading
What is Wolff’s Law?
- bone will adapt to the degree of technical loading, specific to increasing gets strength in resisting the applied load
How is loading of bone primarily caused?
- due to gravity and muscle contraction
How does bone respond to exercise?
- bone remodeling
- bone resorption
What is needed from a load to induce bone formation?
- greater loads more bone growth
- load must be greater than those produced in daily living
- quick loads more bone growth
- exercise combining gravitational and muscle loading more bone growth
What type of exercise promotes bone growth in men, pre/post menopausal women?
aerobic and resistance
How does exercise produce bone resorption?
can acutely disrupt calcium homeostasis
Which type of activities lead to bone resorption?
weight supported exercise like cycling
Who sees more calcium homeostasis disruption?
younger individuals