Voluntary Movement Flashcards
describe voluntary actions
self-initiated, purposeful, learned, improve with practice, adaptable
how are semi-automatic actions different from voluntary actions
they are still voluntary but you don’t have to think about them
what are semi-automatic actions and give examples
repeated movement sequences, adaptable e.g. walking, breathing and chewing
what are semi-automatic actions driven by?
CPGs (central pattern generators)
what do central pattern generators do?
influence whether muscle groups are going to contract or relax
what do the feedback circuits do?
they generate a complex circuit to help you refine the output from the central pattern generators
what type of feedback circuits are fedback to the CPGs?
reflex feedback, sensory feedback, central feedback (once it has gone through the higher control neurons)
how is movement refined?
from recruitment and influences from subcortical areas such as the thalamus and the basal ganglia
what is the circuit of reception to movement when passing through the cortexes?
receptor - spinal cord and brainstem - subcortical areas (thalamus and basal ganglia) - sensory cortex - association cortex - motor cortex - spinal cord and brainstem - muscles - movement
what does the anteriolateral funiculus contain?
secondary order pain receptors
describe the pathways that motor neurons take when innervating muscle groups in the head and neck
at the brain stem the sensory neurons activate lower motor neurons - lower motor neurons target motor nuclei for cranial nerves - these nuclei activate motor neurons which innervate muscle groups
what muscles does the trigeminal nerve supply?
muscles of mastication
what muscles does the facial nerve supply?
muscles of facial expression
what head and neckmuscles does the vagus nerve supply?
soft palate, pharynx, larynx
what muscles does the hypoglossal nerve supply?
extrinsic muscles of tongue
how can axons innervate both side of the body if they only project from one side of the brain
they bifurcate
describe the corticospinal pathway
upper motor neurons send axons down through the internal capsule of brain and brainstem - 85% of axons cross over beneath medulla to other side (contralateral part of spinal cord) this happens at the pyramidal decussation - these neurons are found in the dorsal lateral funiculus - the other 15% of nueorns are in the ventral medial funiculus
what is the difference between the corticospinal and corticobulbar pathways?
the corticobulbar pathway can innervate bilaterally but with the corticospinal pathway the axon has to cross to the other side of the spinal cord
what part of the brain is the motor nucleus of the trigeminal nerve found?
the pons
what part of the brain is the motor nucleus of the facial nerve found?
pons
what part of the brain is the motor nuclei of the vagus and hypoglossal nerves found?
medulla
where do the motor neurons for the distal muscles come from?
the opposite side of the brain
describe the descending motor pathway in terms of synapses
the upper motor neuron comes from the motor cortex and synapses with the lower motor neuron at the brainstem/spinal cord, the lower motor neuron then innervates the muscle and gives movement
what happens if there is damage (lesions) to descending pathways?
it impairs their normal functions causing paralysis - palsy
