Voluntary Movement Flashcards
What are examples of semi-automatic actions?
Walking
Breathing
Chewing
What are semi-automatic actions driven by?
Central pattern generators (CPG)
What are central pattern generators?
Collections of neurons that have a rhythmic output that will influence muscle groups
Why is the hands and face have extended motor units?
Due to the precision needed for contraction
How many neurons are needed in descending motor pathways?
2
Upper motor neuron (motor cortex)
Lower motor neuron (brainstem/spinal chord)
How many neurons are needed in descending motor pathways?
2
Upper motor neuron (motor cortex)
Lower motor neuron (brainstem/spinal chord)
What regions of the white matter are associated with descending projections for voluntary movements?
Dorso-lateral funiculus
Ventralmedial funiculus
On the descending projections for voluntary movement what sections does the motor neurons innervate?
Midbrain
Pons
Medulla
What do branches given of at the pons innervate on the corticobulbar pathway?
-The trigeminal motor nucleus, which innervates the motor branch of the trigeminal nerve
-The facial motor nucleus, innervates the motor neurons of facial nerve
What do branches given of at the medulla innervate on the corticobulbar pathway?
Nucleus ambiguous, motor neurons for the hypoglossal and vagus nerve
What do branches given of at the medulla innervate on the corticobulbar pathway?
Nucleus ambiguous, motor neurons for the hypoglossal and vagus nerve
What is the difference between the corticospinal and corticobulbar pathways?
Corticospinal transcends all the way down the spinal chord while the spinobulbar is just down the brainstem
What is the crossing over of axons at the medulla to spinal chord known as?
Pyramidal decussation
Where do the axons cross in the lateral corticospinal tract?
Dorsal-lateral funiculus (85%)
Where do the axons cross in the anterior corticospinal tract?
Ventralmedial funiculus
