Download Spinal Cord and Spinal Nerves

Spinal Cord
Spinal Cord






42 cm long (17 inches) and 1.8 cm thick
Provides two way conduction pathway to
and from the brain (white matter)
Major reflex center (gray matter)
Enclosed within vertebral column
Extends from skull to the last rib (L1)
Protected by bone, cerebrospinal fluid and
meninges
Spinal Cord



The cord does not extend the
entire length of the vertebral
column
A group of nerves leaves the
inferior spinal cord and extend
downward
Resembles a horses tail and is
called the cauda equina.
Spinal Cord

31 pairs of spinal nerves
arise from the vertebral
column
Cross Section of Spinal Cord


The gray matter in the center surrounds
the central core
Looks like a butterfly
Cross section of Spinal Cord

Two posterior projections


Posterior/Dorsal horns
Two anterior projections

Anterior/Ventral horns
Cross section of Spinal Cord




Neurons with specific functions can be found in the gray
matter
Dorsal horns contain interneurons and cell bodies
Sensory neurons enter through dorsal root ganglion
Motor neurons send their signals through the ventral
root
Cross section of Spinal Cord

White matter in the spinal cord runs in three
directions depending on function



Ascending, descending, and across
Myelinated nerve fibers
Made up of tracts – axons with the same
direction and functions