Get Biology Corner Anatomy Of A Nerve Impulse (anatomy Of A Synapse) 2017-2025

Within a neuron, the impulse moves to the tip of an axon and causes the release of neurotransmitters, chemicals that act as messengers. Neurotransmitters pass through the synapse, the gap between two nerve cells, and attach to receptors on the receiving cell.

Nerve impulses only travel in one direction in neurons. This impulse transmission is dependent on synaptic transmission. This happens because nerve cells only have one transmission site. The receptors also work in one direction.

Neurotransmitters pass through the synapse, the gap between two nerve cells, and attach to receptors on the receiving cell. This process repeats from neuron to neuron, as the impulse travels to its destination — a web of communication that allows you to move, think, feel and communicate.

A synapse is made up of a presynaptic and postsynaptic terminal. The presynaptic terminal is at the end of an axon and is the place where the electrical signal (the action potential) is converted into a chemical signal (neurotransmitter release).

Synapses are composed of three main parts: The presynaptic ending that contains neurotransmitters. The synaptic cleft between the two nerve cells. The postsynaptic ending that contains receptor sites.

Acetylcholine binds with receptors in the post-synaptic membrane. These receptors change shape, opening a channel to allow sodium ions to diffuse in. As the receptors are only present on the post-synaptic membrane, the impulse cannot travel back, so it is unidirectional.

Due to the arrangement of the neurons at the synapse, one will always be the pre-synaptic nerve and the other the postsynaptic nerve. Thus, the nerve impulse can only be transmitted in one direction: from the pre-synaptic nerve to the postsynaptic nerve.