19 terms

The Spinal Cord

Gray Matter
H-shaped; dendrites and neuron cell bodies
White Matter
Bundles of mylienated nerve fibers called spinal tracts
Ascending Tracts
Conducts impulses up the spinal cord to the brain
Descending Tracts
Conducts impulses from the brain down the spinal cord
Loss of sensation
Loss of the ability to make voluntary movements
Sensory Neuron ( Afferent )
Contains receptors that receive impuses from stimuli in tendons, skin, and motor neurons
Interneuron ( Association )
OPTIONAL- conducts impulses between sensory neurons and motor nuerons.
Motor Nueron ( Efferent )
sends impulses from spinal cord to an effector ( a muscle or gland )
Reflex Center
The part of the reflex arc that is within the grey matter of the spinal cord.
Posterior Root Ganglion
Contain hundreds of sensory neuron cell bodies
produces myelin AND allows for regenerations ( something CNS nerves CANNOT do because they do not have neurilemma )
Cranial Nerves
-12 Pairs
-attached to underside of brain
-control areas NOT controlled by spinal nerves
For vision
For eye movement
controls digestive and heart activity
Spinal Nerves
-31 pairs
-attached to spinal cord
-controls impulses from all parts of the body except the tract the cranial nerves control
Largest nerve in the body
Inflammation of the sciatic nerve