Download 1 Chapter 12 Central Nervous System Spinal Cord

1 Chapter 12
Central Nervous System
Spinal Cord
2 Spinal cord dorsal view figure 12.29, pg. 467
3 Spinal cord
4
Gray matter of spinal cord
• Dorsal horns – associated with afferent,
sensory nerve impulses from receptors, C1-L5
neuron cell bodies bundled in dorsal root
ganglion
• Ventral horns – associated with efferent,
motor nerve impulses to effectors, C1-L5
neuron cell bodies are in gray matter of
ventral horn
• Lateral horns – only in in T1-T12 region
5 Spinal cord
• Central nervous system consist of the brain and
the spinal cord.
Afferent peripheral (?)nerves bring nerve
impulses from the receptors (?) to the
spinal cord.
Afferent nerve tracts (?) in the spinal cord
take the nerve impulses to the brain
Bundles of nerve fibers (axons) in the peripheral
nerve system are called nervesBundles of nerve fibers in the CNS are called tracts
6 Spinal Cord
• Nerves and tracts are bundles of axons
• Somewhere near one end of the nerve there
will be the cell bodies of the nerve.
• Often these cell bodies will also be bundled
together.
– If the bundles of cell bodies are in the PNS
they’re called ganglions
– If the bundles of cell bodies are in the CNS
they’re called nuclei. (center of)
7 Spinal cord
• Motor neurons are efferent - descend from
the brain - synapse and go to the spinal cord,
synapse and then out to the effectors
(muscles or glands)
• Sensory neurons are afferent, go from the
receptor to the spinal cord synapse, ascend up
the cord and synapse at the brain