Intro and muscle anatomy - term 1 Flashcards
Why is conditioning purely through strength training been criticized?
- Focus on max strength gains.
- Concentric muscle action
- Utilise isolated muscle groups
- Uni planar movement
Integrated training focuses on functional strength which is the body’s ability to…
- produce force
- reduce force
- dynamically stabilize
Define neuromuscular efficiency
CNS ability to coordinate muscle groups during activity.
What is the stretch shortening cycle (ssc)
Stretch reflex stored potential energy.
What is the structure and organisation of the skeletal muscle starting from the whole muscle?
Muscle —>Fascicles —>Individual muscle fibres —> Myofibrils —>actin and myosin
What is at the neuromuscular junction?
Axon terminals, motor end plates and schwann cell sheaths.
What does the motor end plate contain high concentration of?
ACh receptors
What is the sarcoplasmic reticulum?
A fluid filled membrane that encircles each myofibril.
What does the sarcoplasmic reticulum store?
Ca2+
How many actin filaments encircle the thicker myosin filament?
Six
What does Ca2+ bind to when it’s levels increase in cytosol?
Troponin
What does the troponin-Ca2+ complex do?
Pulls tropomyosin away from G-actin binding site
When tropomyosin is pulled away what happens then?
Myosin binds to actin and completes power stroke
When concentric action is carried out too fast, why does this reduce force?
Actin past myosin too quick, less time for cross bridges to form.
What happens to maximal power due to faster speeds of contraction?
Decreases
Does Fast twitch or slow twitch fibres have greater power?
Fast twitch
Why do fast twitch produce more force?
Because they contain more cross-bridges per cross sectional area
What does the extent of control of a muscle depend on?
The number of muscle fibers within each motor unit.
What does the order of recruitment of muscle fibres depend on?
Exercise intensity and fibre type
What are muscle spindles?
Proprioceptors that consist of several modified muscle fibres enclosed in a sheath of connective tissue
What does the muscle spindle do when a muscle is stretched to cause the muscle to contract?
activates the sensory neuron, which sends an impulse to the spinal cord, where it synapses with a motor neuron.
What does the sensory neuron of the GTO activate?
An inhibitory interneuron in the spinal cord which in turn synapses with and inhibits a motor neuron serving the same muscle.
What is the overall outcome of the GTO?
The muscle relaxes and protects the muscle from damage.
What can resistance training do to the GTO?
Desensitize it
