The part of a neuron that receives signals from other neurons is called:

• A. Axon
• B. Dendrite
• C. Soma
• D. Myelin sheath

Answer: (B)

Receiving signals from other neurons happens mainly through the dendrites. Dendrites are the branch-like extensions of a neuron that bear receptors for neurotransmitters released at synapses from neighboring neurons. When a neurotransmitter binds to these receptors, ion channels open and small graded potentials are produced. These inputs converge and are integrated in the soma, and if the combined signal reaches threshold, an action potential is generated and travels along the axon to communicate with other cells. The soma’s role is to integrate inputs, the axon transmits the outgoing signal, and the myelin sheath speeds conduction along the axon. Dendrites often have many small protrusions called dendritic spines, which increase surface area for receiving synaptic input.