Spinal cord pathways model

These models can be assembled to create a model of the spinal cord and brain which can be used as a learning tool to understand the motor and sensory pathways between the brain and spinal cord. 

This model was designed as a physical version of the animated learning tool AXON: Animated eXploration Of Neuroanatomy, developed by Tom Flanagan and Carol Chan at UCD School of Medicine.

Printing and assembly:

Models in the photos were printed at 150% scale - smaller prints can be used for more compact models. 

All models were printed in PLA (prusament vanilla white), 0.2mm layer height, 15% infill, on Prusa I3 MK3S. Bigger layer heights and lower infills will probably work fine though. For the coronal section of the cerebrum, adding a filament change allows different colours to be used for grey and white matter - eSUN Bone White PLA+ is an good choice for a reasonably realistic contrast colour. 

The printed brain/spinal cord sections are then arranged in order from brain (coronal section of cerebrum), to brainstem (midbrain, pons, medulla), to spinal cord (cervical, thoracic, lumbar). All parts have mounting holes that fit M5 screws. In our case, we drilled corresponding holes in a 1250mm X 500mm X 5mm sheet of acrylic, but plywood (or anything else) could also be used. 

***UPDATE***

We have included a revised version of the of the cerebrum which replaces the pegs in the model with holes sized for M3 (or similar), which cane be used for more robust tie points if needed - the printed pegs may snap off with excessive force.

Using the model to demonstrate the spinal pathways. 

There are lots of ways to use this model, but here's how we have used it - we've included some photos of the model as it was after students had used it in a class. We ask students to draw the rest of the body (head, arms, legs) on the acrylic with whiteboard marker, and then trace the sensory pathways from the hand/feet/face to the sensory cortex. Once assembled on the board, you can thread string/wire from the hands etc. through the holes in each of the spinal cord/brainstem sections, finally attaching to pegs in the thalamus and cortex in the cerebrum section. Just be sure to add something to attach the string to for the start of the pathway - we used a row of holes drilled along either side of the acrylic sheet. In our experience wire is the easiest to use.

Different coloured string can be used to identify different neurons in a pathway (with knots for “synapses”), or different colours for different pathways (spinothalamic, dorsal column, corticospinal etc.). You can also demonstrate the impact of spinal cord lesions (e.g. lateral hemisection) by just cutting the strings at the appropriate place. 

Afterwards, the acrylic can be wiped clean and wires removed, allowing the model to be reused again at a later point.