NURS 220 Lecture Notes - Lecture 19: Dura Mater, Pia Mater, Dorsal Root Ganglion
Document Summary
Ventral horn/dorsal horn-relative to position-where input comes inz. Gray matter: horn cell-in the shape of an h for horn (in middle of spinal cord). D. ) efferent: away from the central nervous system. E. ) decussation: most axons cross over to the contralateral side at some point; smaller portion project ipsilaterally (on the same side as the origin of the track) F. ) somatotopy: a precise spatial relationship among tract fibers that demonstrates an orderly mapping of the body. All information from different parts of body come into their precise spots. Ex) can poke toe in many different parts but all information comes into the same point in the brain. Somatotopy in spinal cord: sensory information from the arm enters lateral to that of the leg. This differential information is carried through different fibers in the tract. All-or-nothing: either the input is strong enough to fire the neuron or nothing happens.
