Motor Units And Muscle Spindles Flashcards
What is the function of synergistic muscles?
They support the main agonist muscles
What are examples of a synergistic relationship?
Brachialis and biceps brachii, anconeous and triceps brachii
What is the function of axial muscles?
They control the trunk
What is the function of the proximal muscles in shoulder, elbo, plvis and knee?
To mediate locomotion
What is the function of distal muscles in the hands, feet and digits?
Fine motor movement
What are the two groups of neurons of the somatic NS?
Upper and lower
Where do upper neurons arise?
In the prmary motor cortex
With what do upper neurons synapse?
Lower neurons
What neurotransmitter acts from the upper neuron to stimulate the action potential?
Glutamate
Where do lower neurons arise?
The spinal cord
From where do the lower neurons recieve the action potential?
The upper neurons
Where do the lower neurons synapse?
The skeletal muscle target
What are the subtypes of the lower neurons?
Alpha neurons innervate bulk fibres in muscle.
Gamma neurons innervate the muscle spindle.
How do lower neurons exit the spinal cord?
In spinal nerves
Where are the cell bodies of lower neuron found?
In the spnal cord
Where do the lower neurons project?
Through the anterior root of the spinal cord
What creates the spinal nerve?
Fusion of the posterior and anterior root
What is the action of spinal nerves?
To end out motor nerves and collect afferent signals
How are the spinal nerves named?
By the vertebra from which they exit
Where do the nerves that create the brachial plexus arise from?
C5-T1
What is the brachial plexus?
The nerves in the neck an shoulders that innervate the arms
What area of the body is innervated by nerves from the lumbo-sacral region?
The lower limb
What will happen following damage to C2?
Death as the diaphragm will be paralysed
What will be the outcome of injury to T1 nerve?
los of function in the lower limb
