Neuromuscular system Flashcards
what is the autonomic nervous system?
the system that controls movement
-controlled by he brain via the nerves
–works involuntarily
what is the peripheral nervous system?
contains the sympathetic + parasympathetic nervous system
–transmits info from the brain to the body parts that need to adjust for exercise
what does the sympathetic nervous system do?
it prepares the body for exercise
what does the parasympathetic nervous system do?
relaxes the body + slows down many high energy functions
what do muscle spindles do?
–detect changes in muscle length/tension/stretch
–prevents over-stretching by initiating the stretch reflex
detects over-stretching-> sends message to the brain->brain sends impulse to muscle for it to contract
what are the 3 muscles fibre types?
–Type 1=Slow Oxidative
–Type 2a= Fast Oxidative Glycolytic
–Type 2b/x= Fast Glycolytic
what are features of the slow oxidative muscles fibres?
-slow contraction speed
-used in low intensity exercise
-produce energy aerobically// very high aerobic capacity
-high mitochondrial density
-high capillary density
-small motor neurone size
-high myoglobin content
-low myosin ATPase activity
e.g: marathon
what are the features of fast oxidative glycolytic muscle fibres?
–fast contraction speed
–generate a greater force of contraction
–more resistant to fatigue
–used where a longer burst of energy is needed
–used for short intense bursts of effort
–produces energy more anaerobically// high anaerobic capacity
–large motor neurone size
–medium mitochondrial/capillary density + myoglobin content
-high myosin ATPase activity
e.g: 400m sprint
what are the features of fast glycolytic muscle fibres?
–fast contraction speed
–generate a greater force of contraction that type 2a
– used for highly explosive events
–fatigue much quicker than type 2a
–produces energy anaerobically// very high anaerobic capacity
–large motor neurone size
–low mitochondrial/capillary density + myoglobin content
–very high myosin ATPase activity
e.g:100m sprint
what does a motor unit consist of?
a motor neurone + muscle fibre types
–only one muscle fibre type can be found in one particular motor unit
explain how motor neurones and muscle fibres work together
–muscle fibres work with the nervous system to allow contractions
–each motor neurone has branches that end in a neuromuscular junction
nerve impulse–>muscles fibre (via motor neurone)
what is the correlation between muscle size and number of muscle fibres?
the larger the muscle, the greater the number of muscle fibres present
what is the all or none law?
–once motor neurones stimulate muscle fibres, either all of them contract or none of them contract
–minimum threshold needed to be met in order for contraction to occur
what is wave summation?
-when muscles contract repeatedly without relaxing, calcium builds up
- causing a stronger tetanic contraction
– allows a performer to have more power to jump/take off/perform the skill correctly
what is spatial summation?
when impulses are received at the same time at different places on the neurone
