BRAINCAKETransmission of Impulse across Synapse
When an action potential reaches the pre-synaptic bulb, calcium ion channels open. The diffusion of calcium ions into the axon causes vesicles containing neurotransmitters to move to the pre-synaptic membrane, fuse with the membrane and release their contents by exocytosis.
Sign in free to see the rest of this lesson, the R.E.C.I.P.E. recall steps and the quiz
BrainCake is free. Make an account in seconds and pick up where this page stops.
Key terms in this lesson
- Action potential
- The temporary reversal of the electrical charge across an axon membrane, from about -70mV to +40mV, that occurs when a neurone is stimulated above threshold.
- Neurotransmitter
- A chemical released from the presynaptic membrane at a synapse that diffuses across the synaptic cleft and binds to receptors on the postsynaptic membrane, triggering a response.
More in Neuronal Communication
- Nerve Impulse
- Saltatory Conduction
- Synapses
- Neurotransmitters
- The Role of Synapses
- Summation
- Structural Organisation of the Nervous System
- Functional Organisation of the Nervous System
All 38 lessons in Neuronal Communication · All OCR A-level Biology topics