Cns Major Structures Flashcards
Where spinal cord originate
Foramen magnum at base if the skull
Describe spinal cord
Encased in vertebral column
Stars at opening of skull, foramen magnum
Is shorter than vertebral column
Adult terminate
Conus medullaris lower border of first lumbar
Children terminate
Conus medullaris upper border of third lumbar
Thus does not extend through all 31 vertebrae
Spinal cord transmit neural signals
Pipeline for motor transmissions from the brain to body via tracts (bundled axons) coursing downwards in efferent manner
And for sensory info being sent to the roan from body via tracts upwards in afferent manner
Efferent
Motor transmissions from brain to body via tracts going downward
Afferent
Sensory info from body to brain via tracts course upward
Spinal cord reflex arc
Coordinates and independently controls reflexive responses and movement
Reflex arc allow for immediate motor movements to sensory input that signal danger
Regions of spinal cord
5 regions of spinal cord
Spinal nerves (part of pns) come and go between openings in vertebrae attaching to spinal cords
Cross section of spinal cord outer layer
White matter Contains ascending (afferent) and descending (efferent) nerve fiber tracts
Inner core layer
Gray matter
H shaped
Posterior horn
Contains sensory neurons
Anterior horn
Motor neuron
Ventral anterior sc
Is involved in transmission of motor output messages
From the brain to the body
In efferent matter
Dorsal/anterior sc
Sensory info
To the Brain from the body
In afferent manner
