Spinal Cord Basics
This structure marks the inferior end of the spinal cord around L1.
Conus medullaris
This part of the spinal cord contains neuron cell bodies.
Gray matter
This root carries sensory (afferent) information.
Dorsal root
This region has 8 pairs of spinal nerves.
Cervical region
These tracts carry sensory information toward the brain.
Ascending tracts
These two enlargements of the spinal cord correspond to the limbs.
Cervical and lumbar enlargements
This horn processes sensory information.
Dorsal horn
This root carries motor (efferent) signals.
Ventral root
This plexus gives rise to the phrenic nerve.
Cervical Plexus
These tracts carry motor commands away from the brain.
Descending tracts
This structure anchors the spinal cord to the coccyx.
Filum terminale
This horn contains motor neuron cell bodies.
Ventral horn
These structures contain sensory neuron cell bodies.
Dorsal root ganglia
This plexus innervates the upper limb.
Brachial plexus
This term refers to crossing over of nerve fibers.
Decussation
This bundle of spinal nerves resembles a horse’s tail.
Cauda equina
These columns carry ascending and descending tracts.
White columns (funiculi)
This branch supplies the muscles and skin of the back.
Dorsal ramus
This major nerve from the sacral plexus is the largest in the body.
Sciatic nerve
Sensory neurons in ascending tracts are typically this type of neuron.
Unipolar neurons
This opening at the base of the skull is where the spinal cord begins.
Foramen magnum
This horn is associated with the autonomic nervous system.
Lateral horn
These branches form nerve plexuses and supply limbs.
Ventral rami
This plexus primarily supplies the anterior thigh.
Lumbar plexus
Motor neurons in descending tracts originate in this brain region.
Cerebral cortex