Biology · Interaction and interdependence
C2.2 — Neural signalling
Biology · SL / HL · syllabus-mapped notes
C2.2.1
Neurons as cells within the nervous system that carry electrical impulses
Describe neurons and the structures that carry impulses.
C2.2.2
Generation of the resting potential by pumping to establish and maintain concentration gradients of sodium and potassium ions
Explain the three factors that generate and maintain the resting potential.
C2.2.3
Nerve impulses as action potentials that are propagated along nerve fibres
Explain depolarization and repolarization, and how impulses are propagated one way.
C2.2.4
Variation in the speed of nerve impulses
Explain how diameter and myelination change impulse speed, and apply correlation coefficients.
C2.2.5
Synapses as junctions between neurons and between neurons and effector cells
Describe the three types of synapse, and explain why signals pass one way only.
C2.2.6
Release of neurotransmitters from a presynaptic membrane
Explain how calcium influx triggers neurotransmitter release.
C2.2.7
Generation of an excitatory postsynaptic potential
Explain how an excitatory postsynaptic potential is generated and then ended.
C2.2.8
Depolarization and repolarization during action potentials
Explain voltage-gating and the sequence of an action potential.
C2.2.9
Propagation of an action potential along a nerve fibre/axon as a result of local currents
Explain how local currents propagate the action potential along an axon.
C2.2.10
Oscilloscope traces showing resting potentials and action potentials
Read resting and action potentials from an oscilloscope trace.
C2.2.11
Saltatory conduction in myelinated fibres to achieve faster impulses
Explain saltatory conduction and why myelination speeds impulses up.
C2.2.12
Effects of exogenous chemicals on synaptic transmission
Explain how neonicotinoids block transmission and how cocaine blocks reuptake.
C2.2.13
Inhibitory neurotransmitters and generation of inhibitory postsynaptic potentials
Explain inhibitory postsynaptic potentials, contrasting GABA with acetylcholine.
C2.2.14
Summation of the effects of excitatory and inhibitory neurotransmitters in a postsynaptic neuron
Explain summation of excitatory and inhibitory inputs, and why it underlies decision-making.
C2.2.15
Perception of pain by neurons with free nerve endings in the skin
Explain how pain receptors generate impulses, and where pain is actually perceived.
C2.2.16
Consciousness as a property that emerges from the interaction of individual neurons in the brain
Explain consciousness as an emergent property, and what can and cannot be claimed about it.