Why is the flow of signals in a synapse from the axonal end of one neuron to the dendritic end of an

Why is the flow of signals in a synapse from the axonal end of one neuron to the dendritic end of another neuron but not the reverse?

Answer

• In nerve cells signals go from;

Dendrites → Soma → Axon → Nerve endings → Synapse → Dendrite of next neuron

• Signals are in the form of electric impulses as they pass from dendrites to nerve endings .
• Signals are in the form of chemicals called neurotransmitters during transmission of messages across the synapse .
• The chemicals called neurotransmitters are not present in the dendrites, they are only present in the axon. 
• So, the dendrites cannot convert electrical impulses to chemical impulses . Thus the flow of signals in a synapse is from the axonal end one one neuron to the dendritic end of another neuron but not the reverse.