Somatic- Volntary Skeletal Flashcards
Sns Innervate to/from all
Skeletal muscle
Somatic nervous system: voluntary control of skeletal muscle
Provide conscious, voluntary control
Sns outgoing dependent upon
Tracts leaving the cortex, traveling down the spinal column and synapsing with new motor neurons before exiting the cns
Sns efferent nerves leaving the cns now traveling
As apart of the pns, an synapsing directly with muscle–> causing/firing muscle movement
Sns incoming afferent nerves entering the cns coming directly
From skin or muscle ( temp,pressure, pain, texture)
Sns incoming nerves synapse with
Other sensory neurons along he way now traveling as part of cns –> providing sensory info form the pns
Close laptop lid Brain pathway
Premotor to plan- primary motor- projection fibers (corona radiati/ internal capsule)- basal ganglia to edit- cerebellum to fix once start
And reflex arcs provide
Conscious, voluntary Control
Reflex arc directly mapped/linked
Sensory-motor system in the pns
Reflex arc located
At the level of the spinal nerves involved in the pns
Reflex ace bypasses the
Cns altogether and provides for immediate responses to external stimuli
Act in a protective manner to minimize danger
Upper motor neurons are all located
In the cns- cell body
Axons from UMNs do not leave the cns …
They remain within the brain, brainstem, and/or the spinal cord
UMNs originate in the
Premotor cortex of the frontal lobe
Axons of the UMN corticospinal tracts and
corticobulbar tracts
Corticospinal
Projection fibers traveling vertically
Sending axons to synapse with lower motor neurons in the spinal cord
Corticobulbar tracts
Projection fibers traveling vertically
Sending axons to synapse with cranial nerve nuclei in the brainstem
UMNs provide for a direct activation system
From cns to pns –> direct link between UMN and LMN doe. In the spinal cord, direct route for voluntary movement
UMN referred to as
Direct activation pathway
Direct motor system
Pyramidal tract (because they decussate at the level of a structure referred to as the pyramid in the brainstem
Lower motor neurons (cell bodies and axons)
Those neurons which convey the neural impulse to its final destination
LMN
Cell body in the cns
Axon extend out of the spinal cord or brainstem and into the periphery which is in the pns
LMN fiction to x
Receive incoming UMN message from the motor Cortex
Transmit that incoming motor impulse to the muscle itself
Cause the muscle itself to fire/move/contract
LMN entIre system called
The diablo common pathway
LMN also called
2nd order neurons, cranial nerve neurons, anterior horn cells, alpha motor neurons
Where do efferent tracts cross over
Medulla
Signal travel in spinal cord
Travel down ipsalaterally and at medulla cross over and travel contra laterally until reaches LMN
