Answer
The posterior columns of the posterior-medial lemniscal pathway are the cuneate fasciculus(bundle) and the cuneate fasciculus.The posterior-medial lemniscal tract is a combined white matter tract which comprises the posterior tract of the spinal cord, and the lemniscal tract of the brainstem
Work Step by Step
The posterior columns are comprised of first order neurons with their cell bodies in dorsal root ganglia of the spinal cord. Their axons enter the spinal cord travel to the cuneate and gracile nuclei (on the same side) in the medulla. These ascending axons form two white matter tracts known as the cuneate and gracile fasciculi. In the nuclei of the medulla the axons of the dorsal columns synapse with dendrites of second order neurons of the dorsal-medial meniscal pathway which then cross to the other side.The axons of the cuneate tract carry impulses from receptors(touch, pressure, vibration, conscious proprioception) that serve upper limbs, upper trunk, neck, posterior head). Axons of the gracile tract transmit similar sensory impulses from lower limbs and the lower part of the trunk.
