Posterior column
Encyclopedia
thumb
Posterior column or dorsal column refers to the area of white matter in the dorsomedial side of the spinal cord
. It is made up of the fasciculus gracilis
and fasciculus cuneatus
and itself is part of the dorsal funiculus. It is part of an ascending pathway that is important for well-localized fine touch and conscious proprioception
called the posterior column-medial lemniscus pathway
.
Joint capsules, tactile and pressure receptors send a signal through the dorsal root ganglia up through the fasciculus gracilis
for lower body sensory impulses and the fasciculus cuneatus
for upper body impulses. Once the fasciculus gracilis
reaches the nucleus gracilis and the fasciculus cuneatus
reaches the nucleus cuneatus in the lower medulla, they begin to cross over the medulla as the internal arcuate fibers
. When they reach the contralateral side, they become the medial lemniscus
, which is the second part of the posterior column-medial lemniscus pathway
.
Lesions in this pathway can diminish or completely abolish tactile sensations and movement or position sense below the lesion.
Posterior column or dorsal column refers to the area of white matter in the dorsomedial side of the spinal cord
Spinal cord
The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain . The brain and spinal cord together make up the central nervous system...
. It is made up of the fasciculus gracilis
Fasciculus gracilis
The fasciculus gracilis is a bundle of axon fibres in the posterior column of the spinal cord and carries information from the middle thoracic and lower limbs of the body...
and fasciculus cuneatus
Fasciculus cuneatus
The fasciculus cuneatus is a tract of nerves in the spinal cord which primarily transmits information from the arms...
and itself is part of the dorsal funiculus. It is part of an ascending pathway that is important for well-localized fine touch and conscious proprioception
Proprioception
Proprioception , from Latin proprius, meaning "one's own" and perception, is the sense of the relative position of neighbouring parts of the body and strength of effort being employed in movement...
called the posterior column-medial lemniscus pathway
Posterior column-medial lemniscus pathway
The posterior column-medial lemniscus pathway is the sensory pathway responsible for transmitting fine touch, vibration and conscious proprioceptive information from the body to the cerebral cortex; as well as tactile pressure, barognosis, graphesthesia, stereognosis, recognition...
.
Joint capsules, tactile and pressure receptors send a signal through the dorsal root ganglia up through the fasciculus gracilis
Fasciculus gracilis
The fasciculus gracilis is a bundle of axon fibres in the posterior column of the spinal cord and carries information from the middle thoracic and lower limbs of the body...
for lower body sensory impulses and the fasciculus cuneatus
Fasciculus cuneatus
The fasciculus cuneatus is a tract of nerves in the spinal cord which primarily transmits information from the arms...
for upper body impulses. Once the fasciculus gracilis
Fasciculus gracilis
The fasciculus gracilis is a bundle of axon fibres in the posterior column of the spinal cord and carries information from the middle thoracic and lower limbs of the body...
reaches the nucleus gracilis and the fasciculus cuneatus
Fasciculus cuneatus
The fasciculus cuneatus is a tract of nerves in the spinal cord which primarily transmits information from the arms...
reaches the nucleus cuneatus in the lower medulla, they begin to cross over the medulla as the internal arcuate fibers
Internal arcuate fibers
Internal arcuate fibers are the axons of second-order neurons contained within the gracile and cuneate nuclei of the medulla oblongata.These fibers cross from one side of the medulla to the other to form the medial lemniscus....
. When they reach the contralateral side, they become the medial lemniscus
Medial lemniscus
The medial lemniscus, also known as Reil's band or Reil's ribbon, is a pathway in the brainstem that carries sensory information from the gracile and cuneate nuclei to the thalamus.-Path:...
, which is the second part of the posterior column-medial lemniscus pathway
Posterior column-medial lemniscus pathway
The posterior column-medial lemniscus pathway is the sensory pathway responsible for transmitting fine touch, vibration and conscious proprioceptive information from the body to the cerebral cortex; as well as tactile pressure, barognosis, graphesthesia, stereognosis, recognition...
.
Lesions in this pathway can diminish or completely abolish tactile sensations and movement or position sense below the lesion.