Neuromuscular System :) Flashcards
sympathetic nervous system
prepares the body for exercise and is often referred to as the fight or flight response
parasympathetic nervous system
relaxes the body and slows down high energy functions and if referred to as the rest and relax response
contraction speed (func)
type 1: slow
type 2a: fast
type 2b fast
motor neuron size (struc)
type 1: small
type 2a: large
type 2b: large
motor neuron conduction capacity (func)
type 1: slow
type 2a: fast
type 2b: fast
force produced (func)
type 1: low
type 2a: high
type 2b: high
fatigability (func)
type 1: low
type 2a: medium
type 2b: high
mitochondrial density (struc)
type 1: high
type 2a: medium
type 2b: low
myoglobin content (struc)
type 1: high
type 2a: medium
type 2b: low
capillary density (struc)
type 1: high
type 2a: medium
type 2b: low
aerobic capacity (func)
type 1: very high
type 2a: medium
type 2b: low
anaerobic capacity (func)
type 1: low
type 2a: medium
type 2b: very high
atpase/glycolytic enzyme activity (func)
type 1: low
type 2a: medium
type 2b: very high
motor unit
consists of a motor neuron and a group of muscle fibres
~only one type of muscle fibre is found in one motor unit~
motor neuron transmits the nerve impulse to muscle fibre
all or none law
where a sequence of impulses has to be of sufficient intensity to stimulate all of the muscle fibres in the motor unit in order for them to contract. if not, none of them contract
wave summation
repeated activation of motor neuron with no time to relax in between, causing a smooth sustained contraction to occur
tetanic contraction
a sustained powerful muscle contraction caused by a series of fast repeating stimuli
spatial summation
motor units within a muscle are activated at slightly different times meaning the muscle is able to sustain a continuous contraction over a period of time
additional, bigger motor units are recruited to develop more force
pnf
1) passive stretch occurs with the help of a partner until tension is felt and detected by the muscle spindles
2) isometric stretch for at least 10 seconds by pushing against partner who provides resistance to hold the leg still
3) leg is passively stretched again and will go further than before
muscle spindles
proprioceptors that lie between skeletal muscle fibres
provide info to cns about how fast and far a muscle is being stretched
cns sends impulse back telling muscle to contract triggering stretch reflex
golgi tendons
found between muscle fibres and tendons
detect levels of tension in muscles
during isometric contraction in pnf - senses increase in tension and sends inhibitory signals to brain to allow antagonist muscle to relax and lengthen
autogenic inhibition
sudden relaxation of the muscle in response to high tension
during isometric contraction in pnf - senses increase in tension and sends inhibitory signals to brain to allow antagonist muscle to relax and lengthen
