Final answer:
Axon terminals contain synaptic vesicles that house neurotransmitters, which are crucial for transmitting signals to other neurons across synapses.
Step-by-step explanation:
Axons branch into axon terminals, which have synaptic vesicles located at the terminal ends. These synaptic vesicles contain neurotransmitters, which are released into the synapse, a complex membrane junction between neurons, when an action potential reaches an axon terminal. The neurotransmitters then bind to receptor sites on the dendrites of the next neuron, allowing the signal to be communicated and initiating a new action potential in the receiving neuron.