Impulses run at each fibre type's real conduction speed, slowed down by the amount chosen. Timings and colours are a teaching approximation.
Not to scale: a cell body is about 20 µm across and each myelin segment about a millimetre long; the segments are drawn much shorter.
3D models: VOKA 3D Anatomy, as used in G8 Anatomy. The impulses run along the centre lines of VOKA's nerves, spinal cord and brainstem.
Pathways: Gener8. The spinothalamic (pain and temperature), dorsal column–medial lemniscus (touch) and corticospinal (movement) pathways follow standard neuroanatomy texts. Where VOKA has no part for a structure (dorsal root ganglion, pons and midbrain, internal capsule, cortex areas) the route passes through points placed from the parts around them.
Fibre types and speeds: Erlanger–Gasser classification: Aα 80–120 m/s, Aβ 35–75 m/s, Aδ 5–30 m/s, C 0.5–2 m/s. The impulses run at a typical speed for each, slowed by the amount chosen.
Neuron close-up and conditions: Gener8. The action potential follows the textbook sequence (sodium in, potassium out, refractory period) and the saltatory conduction of myelinated fibres. Multiple sclerosis and Guillain–Barré levels are teaching approximations drawn from NICE NG220 (multiple sclerosis) and standard descriptions of demyelinating neuropathy.
Educational model. Speeds, timings, sizes and colours are a teaching approximation, not for diagnosis or treatment. The text needs a check by someone with neuroscience knowledge before client use.