Chapter 6 · Biology
Control and Coordination
A reflex is fast because it skips the brain. The module here computes the actual response time from nerve length, conduction velocity and synaptic delay — so 'faster than thinking' becomes a number.
Reflex Action & Plant Response Lab
Trigger a stimulus and watch the nerve impulse travel; explore synapses and tropisms in plants.
- Pathway
- Receptor → Sensory → Spinal cord → Motor → Effector
- Estimated reaction time
- 120 ms
- Involves thinking?
- No — involuntary
- Synapse chemical
- Neurotransmitter (e.g. acetylcholine)
Formula sheet
Conduction time
t = distance / conduction velocity
Nerve impulses travel at roughly 1–120 m/s depending on the fibre.
Reflex time
t_total = t_conduction + (number of synapses × synaptic delay)
Each synapse adds roughly 0.5–1 ms.
Reflex arc
Receptor → Sensory neuron → Spinal cord → Motor neuron → Effector
The brain is only informed afterwards.