Motor Unit and Movement Flashcards
What is the Somatic Nervous system
a branch of the peripheral nervous system which consists of skeletal muscle and their neural control elements
also is voluntary movements
Define these words for movement of the brachial and brachialis and tricep brachii and anceoneus
Synergist
Antagonist
Synergist - when they work togther to make both muscle groups more powerful
biceps brachii and brachilais work together
antagonists means that they have different functions
bicepso brachii and brachilias cause flexor and oppose tripceos brachii and anceonous extensors
What does axial muscles control
where are these found
movement of the trunk proximal muscle
shoulder , elbow, pevlis , knee and distal muscle move hands feet and digits
What are the two subdivsions of motor neruons in the somatic nervous system
where do these arise and use what neurotransmitter
Upper Motor neruons - arise in cerebral cortex and use glutamate neurotransmitter
Lower motor Nuerons - arise from spinal cord and use acetylcholine as neurotransmitter
Where do lower motor neurons exit
what does this provide
what do the nerves do
Exit the spinal cord in the spinal nerves
provide both motor and sesnory supply to skeletal muscle (and sesnory input from skin visceral receptors)
innverate muscle roughly at the spinal segment
System for the movement of sensory and motor neruons from vertebrae to the brain
spinal cord to the anterior root of motor and sensory are at the part of the spinal nerve
these converae and rise anterior root
spinal cord goes through anterior root
What is a motor unit and pool
Unit - a motor neuron and all of the sketla muscle it innervates
pool - single muscle innervated by group of a motor neurons
What is force of contraction from a motor neuron infleucnes by
relationship between force of contraction and action potential
Motor unit recruitment
frequency of action potential generated
greater the force of contraction the bigger action potential generated which will influence contraction
What do smaller and larger motor units control
what are they innervated by
examples of these
Smaller - finer movements and are innervated by smaller a motor neurons (extracolar muscles of the eyes)
Larger - control postural muscles innervated by larger a motor neuorns (pectolaris and erecetor spinae)
Fast fatiguing Motor Units:
Tension
rate
size of a Motor Neurons and threshold
and type of fibre
Example
very high tension
fast fatiguging
larger a MN and higher threshold
Type IIx fibres
Burst power
fatigue resistant Motor Units:
Tension
rate
size of a Motor Neurons and threshold
and type of fibre
Example
high tension
slow fatiguging
intermedaite a MN and threshold
Type IIa fibres
Susatined locomotion
slow fatiguing Motor Units:
Tension
rate
size of a Motor Neurons and threshold
and type of fibre
Example
low tension
fatiguging resistance
slow a MN and threshold
Type I fibres
Antigravity sustained moevment
