Action potentials and synaptic transmission

What you’ll practice

Work through key ideas behind membrane excitability, action potential phases, and how signals move from one neuron to the next. You’ll also connect mechanisms to outcomes, like how channel changes alter firing rate or how synapses shape postsynaptic potentials.

Every question uses 4 options and there’s no timer, so you can focus on reasoning instead of speed. Choose your question count before starting, and pick an easier or harder mix depending on whether you’re reviewing basics or training for exams.

Common pitfalls to avoid

Many mistakes come from mixing up which ions drive each phase, or confusing equilibrium potential with resting membrane potential. Another frequent trap is treating EPSPs/IPSPs like all-or-none events rather than graded signals that sum over time and space.

• Confusing voltage-gated vs ligand-gated channel roles in signaling
• Mixing up threshold, refractory periods, and firing frequency
• Forgetting driving force when predicting ion movement and PSP direction
• Treating synaptic potentials as identical across synapse locations and timings
• Overlooking presynaptic steps like Ca2+ entry and vesicle fusion

How the difficulty is balanced

Difficulty is mixed: you’ll see straightforward definitions alongside scenario-based questions that require applying principles to graphs, channel states, or synaptic outcomes. The set is designed to ramp up naturally, with easier recall items interleaved to keep momentum while still challenging your understanding.