Sue - Neuromuscular Flashcards
What is the role of muscle spindles?
They detect how FAR and how FAST a muscle is stretched and produce stretch reflex
What is the role of Golgi Tendon Organs?
They detect levels of tension in a muscle. When a muscle is being stretched in PNF, they sense tension and send inhibitory signals to the brain which allows lengthening of the muscle
What type of contraction occurs in PNF?
Isometric
Basic description of PNF
Passive stretch, muscle spindles detect stretch, stretch reflex occurs, isometric stretch for 10s with resistance, Golgi-tendon organs activated, signals to override the signals from muscle spindles, delays stretch reflex
= allows the leg to stretch further
Sympathetic system is the……………………………….response
‘Fight or flight’
Parasympathetic system is the………….response
‘Rest and relax’
What are muscle fibres and motor neurones grouped into?
Motor units
What type of motor unit would a small muscle used for fine motor control have?
Small motor unit
What type of motor unit would a large muscle used for gross motor control have?
Large motor unit
What two types of fibres can be present in motor units?
Fast-twitch fibres and Slow-twitch fibres
In order to achieve maximal contractions, what is needed?
A large motor unit, containing fast-twitch fibres and recruitment of lots of motor units
Where a sequence of impulses has to be of sufficient intensity to stimulate ALL of the muscle fibres in a motor unit in order for them to contract
All or none law
Where there is repeated nerve impulse with no time to relax so a smooth, sustained contraction occurs rather than twitches
Wave summation
A sustained powerful muscle contraction caused by a series of fast repeating stimuli
Tetanic contraction
When the strength of contraction changes by the altering the number and size of the muscle’s motor units
Spatial summation
