Anterior white commissure
Encyclopedia
The anterior white commissure, also known as the alba anterior medullae spinalis, is a bundle of nerve fibers which cross the midline of the spinal cord just anterior to the gray commissure
(Rexed lamina
X). A δ fibers
and C fibers carrying pain sensation in the spinothalamic tract
contribute to this commissure, as do fibers of the anterior corticospinal tract
, which carry motor signals from the primary motor cortex
.
Gray commissure
The gray commissure is a thin strip of gray matter that surrounds the central canal of the spinal cord and, along with the anterior white commissure, connects the two halves of the cord. It comprises lamina X in the Rexed classification....
(Rexed lamina
Rexed laminae
The Rexed laminae comprise a system of ten layers of grey matter , identified in the early 1950s by Bror Rexed to label portions of the spinal cord...
X). A δ fibers
A delta fiber
A delta fibers, or Aδ fibers, are a type of sensory fiber.They are associated with cold and pressure, and as nociceptors stimulation of them is interpreted as fast/first pain information....
and C fibers carrying pain sensation in the spinothalamic tract
Spinothalamic tract
The spinothalamic tract is a sensory pathway originating in the spinal cord. It transmits information to the thalamus about pain, temperature, itch and crude touch...
contribute to this commissure, as do fibers of the anterior corticospinal tract
Anterior corticospinal tract
The anterior corticospinal tract is a small bundle of descending fibers that connect the cerebral cortex to the spinal cord...
, which carry motor signals from the primary motor cortex
Primary motor cortex
The primary motor cortex is a brain region that in humans is located in the posterior portion of the frontal lobe. Itworks in association with pre-motor areas to plan and execute movements. M1 contains large neurons known as Betz cells, which send long axons down the spinal cord to synapse onto...
.