Download Spinal Cord Tracts

Spinal Cord Tracts
The white matter of the spinal cord is divided into the paired posterior
(dorsal), lateral, and anterior (ventral) columns. These columns are
sometimes called funiculi (or funiculus when singular) and are made
up of axons that are traveling up (ascending) or down (descending) the
spinal cord. The ascending tracts generally carry sensory information
from the periphery to the brain, while the descending tracts carry motor
signals to muscles and glands.
The columns can be further divided into tracts (sometimes
called fasciculi), which is a way of functionally grouping the neurons
based on similar origin, destination and function. These tracts are often
named for the structures that they connect. For example,
the spinothalamic tract indicates that the fibers are carrying
information from the spinal cord to the thalamus of the brainstem. You
may note from its name that it is an ascending tract, so the information
that it carries is sensory.
Some of the tracts cross over (decussate) either in the spinal cord or
brainstem, and when this occurs, the relationship between the origin
and destination is termed contralateral. Much of our motor control is
contralateral. For example, the motor area in your left-brain mainly
controls your right arm. When the origin and destination of a tract are
on the same side of the body, it is referred to as an ispsilateral
relationship.
Spinal Tracts
Tract
Column
Location
Dessusitation
location
Function
Ascending Tracts - Sensory
Gracile
fasciculus
posterior
medulla
below level T6: limb and trunk
position sensations; deep touch;
visceral pain; vibration
Cuneate
fasciculus
posterior
medulla
level T6 and above: limb and
trunk position sensations; deep
touch; visceral pain; vibration
Spinothalamic
lateral and
anterior
spinal cord
light touch, tickle, itch,
temperature, pain, and pressure
sensations
Spinoreticular
lateral and
anterior
some fibers of the
spinal cord
pain sensation from tissue injury
Posterior
spinocerebellar
lateral
none
proprioception - feedback from
muscles
Anterior
spinocerebellar
lateral
spinal cord
proprioception - feedback from
muscles
Descending Tracts - Motor
Lateral
corticospinal
lateral
medulla
fine limb control
Anterior
corticospinal
anterior
spinal cord
fine limb control
Tectospinal
anterior
midbrain
head-turning reflex in response to
visual and auditory stimuli
Lateral
reticulospinal
lateral
none
posture and balance; awareness of
pain regulation
Medial
reticulospinal
anterior
none
posture and balance; awareness of
pain regulation
Spinal Tracts
Lateral
vestibulospinal
anterior
none
posture and balance
Medial
vestibulospinal
anterior
some fibers of the
medulla
head position control