C2.2 Neural signalling

Neural signalling transmits information through neuron structure, ion gradients, action potentials, synapses and chemical modulation of postsynaptic responses, linking cellular mechanisms to rapid communication in nervous systems.

What you’ll learn

16 learning objectives

Choose one objective for a focused lesson, or study the complete topic.

Exam analysis

An aggregate view of how the complete C2.2 Neural signalling appears across past papers.

Chance of appearing50%of analysed past papers

Latest appearanceNovember 2025

Most common paperPaper3

Most tested objectives

C2.2.12 (HL)—Exogenous chemicals20 questions
C2.2.5—Synapses as junctions11 questions
C2.2.8 (HL)—Depolarization and repolarization11 questions

Common question formats

Calculation
Comparison
Data analysis
Diagram interpretation
Process explanation
Structured response
Definition or recall

Exam question appearances

November 2025Paper2 ["HL"] · TZ18(b)[ 7 ]C2.2.6—Neurotransmitter release

November 2025Paper1B ["HL"] · TZ13(d)[ 3 ]C2.2.11 (HL)—Saltatory conduction

November 2025Paper1B ["HL"] · TZ13(c)(ii)[ 1 ]C2.2.4—Variation in impulse speed

November 2025Paper1B ["HL"] · TZ13(c)(i)[ 1 ]C2.2.4—Variation in impulse speed

November 2025Paper2 ["HL"] · TZ33(c)[ 3 ]C2.2.12 (HL)—Exogenous chemicals

Practice this topic

7 original exam-style questions based on the patterns above.

Coverage 2012–2025 · Updated 15 Jul 2026