Answer:
from the axon hillock toward the axon terminals.
Step-by-step explanation:
Axon hillock is a cone-shaped elevation of an axon. It is the region where axons join the cell body. In most neurons, nerve impulses arise at the junction of the axon hillock and the initial segment of axons. This region is called the trigger zone. From this region, a nerve impulse travels towards axon terminals. Axon terminals may have synaptic end bulbs at their tips. As nerve impulse travel from axon hillock to the axon terminal, synaptic vesicles having neurotransmitters are released into the synaptic cleft.