Which extension passes messages to other neurons or to muscles or glands?

• A. Dendrite
• B. Axon
• C. Myelin Sheath
• D. Neuron

Answer: (B)

Axons are the long extensions that carry messages away from a neuron’s cell body toward other neurons or to muscles and glands. The signal travels as an electrical impulse along the axon and is released at the axon terminals into the synapse, where neurotransmitters communicate with the next cell. Dendrites, by contrast, are the receiving parts that collect signals from other neurons and don’t pass messages along to effectors. The myelin sheath speeds up the transmission along the axon but doesn’t itself convey the message. The neuron is the whole cell, not just a single extension.