How would you descrive the transmission of a nerve impulse across a synapse?

1 Answer
Jun 29, 2016

Nerve impulse transmission across synapse takes place by
1. Neurosecretion and
2. Chemoreception.

Synaptic transmission is achieved by use of neurochemicals.


Synapse has three structural entities:

  1. presynaptic axonic terminal/knob,
  2. synaptic cleft and
  3. postsynaptic dendritic terminal/membrane.

Synaptic impulse transmission takes place from presynaptic to postsynaptic neuron.

  • When nerve impulse reaches presynaptic terminal, calcium ions flow in. This prompts secretory vesicles stored inside axonic terminal to burst and release neurohumor substances in synaptic cleft.
  • Neurohumor molecules act as neurotransmitters, and are of different types: acetylcholine, serotonin, etc. Neurotransmitter molecules diffuse through synaptic cleft and reach dendritic terminal.
  • Postsynaptic dendritic membrane ramains associated with specific receptors for specific neurohumor. Attachment of neurohumor to receptor causes depolarisation and a new action potential is formed in the postsynaptic neuron.