neuromuscular system and exercise Flashcards
what is excitation-contraction coupling?
- this is the events that lead to an action potential occurring in the sarcolemma, that allows the myofilamnent to slide, resulting in contraction.
what are the 3 phases of excitation-contraction coupling?
- spread of depolarization
- binding of calcium to troponin.
- generation of force (cross-bridge cycling)
discribe cross-bridge cycling?
- cyclic events that are necessary for the generation of force or tension within the myosin head during muscle contraction.
the nervous system divides into what 2 systems?
- somatic nervous system
- autonomic nervous system.
what is the somatic and autonomic nervous system responsible for?
SOMATIC
- contraction of muscle fibres through the efferent neurons
- controles skeletal muscle.
AUTONOMIC
- controls heart, glands, hallow organs, and maintaining homeostasis.
- controls visceral and smooth muscle
what is the sliding filament theory?
- this is the force of how muscle contraction generates force, which occurs during concentric force.
what are the 3 principle of sliding filament theory?
- the force of contraction is generated by the actin filament (thin) sliding over the myosin filament (thick), which exposes the binding site for calcium to bind, allowing for contraction. The force is produced because the actin filament decreases the space between adjacent actin molecules which shortens the muscle fibre and producing contraction.
- length of thick and thin filaments do not change during contraction.
- length of sarcomere decrease as the actin filaments slide over the myosin filaments and pull the z disk towards the center of the sarcomere.
name the 4 measurements of studying muscle?
- electromyograph
- muscle biopsy
- imagining and spectroscopic techniques
- isokinetic dynamometry & force transducers
what is a electromyograph (EMG)?
- muscle action potentials that allow for muscle contraction.
- force of static contraction X tension of consistent-velocity contraction.
- this allows for the use of muscle recruitment patterns.
- voltage with the amount of force.
what is a muscle biopsy?
- muscle is removed from someone in which it is able to be analyzed what type of muscle fibre types are present in a certain muscle.
what is imagining and spectroscopic techniques?
- CT, MRI, ultra sound.
- this can evaluate how much fat and how dense a muscle is in a certain area.
what is isokinetic dynamometry (ID) and force transducers? (FT)
ID
- velocity of movement of a limb throughout contraction that is hooked up to a computer.
FT
- measures static endurance and stregrenth, and is based on how long the subject can hold that position for.
overview of thick filaments (myosin)?
- numerous myosin protein strands
- filament heads that protrude outwards.
- myosin head attaches to active site on the actin filament (thin)
- the myosin head contains mATPase to breakdown ATP and energy to be released.
what are 3 thin filaments?
- actin
- 2 protein strands twisted around each other. - tropomyosin
- thin strand laying in the actin groove that COVERS the active site. - troponin
- attached to actin and tropomyosin strands: has a strong want for Ca2+.
cytoskeletal structural protein?
- M-band
- located in middle of thick filament (myosin)
- contains creatine kinase - titan
- connects myosin filaments to z-disks.
- stabilize myosin in the middle of sarcomere - z-disk
- thin filament attchment.
- contains several cytoskeletal proteins