Regional Divisions of the Spinal Cord
How many segments are in the spinal cord?
31 segments: 8 cervical, 12 thoracic, 5 lumbar and 5 sacral and 1 coccygeal in the vertebral canal.
Where does the spinal cord end in adults?
it ends after L1 or L2 and the canal is filled with roots known as the cauda equine
What is gray commissure?
it has axons that connect the Left and Right gray area
How is the gray matter divided?
it has the dorsal and ventral horn with an intermediate gray area
how is the white matter divided?
it has the ventral, lateral and dorsal faniculi or columns
What is the rexed laminae?
it is the 10 layers of the gray matter
What is the central canal?
it sits in the commissure
Where does the spinal cord taper off?
it tapers off starting at T12-T1 becoming the conus medularis.
Where are the cell bodies for the motor and sensory neurons?
the cell bodies for the sensory neurons are in the dorsal root ganglia and the cell bodies for the motor neurons are in the gray matter.
How is the spinal cord divided?
the ventral aspect has the anterior median fissure while the dorsal side has the posterior septum
What are preganglionic nerves?
they are spinal nerves from T1 to l3 and are part of the sympathetic nervous system
What does the faniculi do?
It carries information from the CNS and TO the CNS
How does the spinal cord anchor onto the coccyx?
a root coming off the pia mater known as the filum terminal anchors it to coccyx.
What does each spinal segment have?
a spinal nerve which is a merging of the ventral and dorsal root