38. 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?

The electrical impulse travels through a neuron. But to be transmitted to another neuron, it needs to be passed in the form of neurotransmitters. Neurotransmitters are specialized chemicals. They can enter a neuron only through specialized channels. Such channels are present in dendrites but not in axons. On the other hand, a neurotransmitter can enter a dendrite. Due to this, the flow of signals in a synapse is from the axonal end of one neuron to the dendritic end of another neuron but not the reverse.