Lucas part 6 Flashcards
3 components of the CNS
Motor cortex, cellebrum, spinal cord
4 main purposes of skeletal muscle control systems
Voluntary Motion
Coordination of Multiple Muscles
Graded Force Levels (adjust contraction intensity)
Automatic Systems (reflexes)
which part of the CNS controls voluntary motion
motor cortex
what does the cerebellum do
coordinate timing and accuracy of complex movements
what does the spinal cord do in the CNS
Houses central pattern generators for rhythmic activities like walking, and reflex arcs for automatic responses
whats the order that leads to a motor output
stimuli - sensory neuron - interneuorn - motor neuron - muscle
Signals from the ____travel down to motor neurons in the spinal cord.
motor cortex
____ motor neurons directly control muscle contraction.
alpha
____ lets us modulate the level of force produced by a muscle
modulate
____ levels of force are achieved through ____
graded, summation
temporal vs spatial summation
temporal: single presynaptic neuron sends signals to a postsynaptic neuron at a rapid rate, the signals add up.
spatial:** multiple** presynaptic neurons send signals to a postsynaptic neuron at the same time, the signals add up
Small motor units involve =
Large motor units involve =
fine control (e.g., fingers).
strong force (e.g., thighs).
Problem: Too many motor units (thousands) for the brain to control individually.
Solution: ?
Solution: Recruitment based on the size principle
small alpha neurons are used for:
SO fibres, slow endurance tasks
big alpha neurons are for:
FG fibres, powerful, short bursts.