Which part of a neuron receives signals?

• A. Synapse
• B. Dendrites
• C. Axon
• D. Soma

Answer: (B)

Signals are received by the dendrites because they are the neuron’s primary input surfaces. Their branched membranes are studded with receptors for neurotransmitters released from other neurons at synapses. When a neurotransmitter binds to these receptors, ion channels open and small electrical changes—postsynaptic potentials—occur. These inputs accumulate and are integrated mainly in the cell body and at the axon hillock; if the combined signal is strong enough, an action potential is triggered and travels down the axon. The synapse is the communication junction, but the actual reception of the signal happens on the dendritic membrane due to its high receptor density and large surface area. The axon, in contrast, carries signals away from the neuron, not reception, and the soma primarily integrates inputs rather than serving as the main receiving site.