Making Sense of Touch with The Dorsal Column System
Throughout our lives we have used our sense of touch to perceive the
environment around us. But, how does our body exactly interpret skin
stimulation? Humans have several skin receptors that enable us to
detect various stimuli, which in turn send signals to the brain.
Although there are a few skin receptors that have been studied over the
years, the Meissner corpuscle and it’s ability to perceive form
will be looked at in this storyboard. Let’s take a look at how
this touch receptor works:
First, a Meissner corpuscle, which has a relatively large receptive
field, detects stimulation along the skin and sends action potentials
along the axons of a cutaneous nerve. These axons, which belong to
unipolar neurons, enter the dorsal roots of the spinal cord and travel
to the spinal column dorsal horn.
The axons now travel along side the spinal cord’s dorsal column
of white matter and move upwards toward the brain. Moving up to the
brainstem, an axon synapses on a neuron of the dorsal column nuclei in
the medulla. This neuron’s axon then crosses the midline and
travels to nuclei in the thalamus. Finally, the left thalamus receives
the information from the periphery and sends the received information
to the somatosensory cortex.