When a neural impulse reaches the end of an axon, it causes the tiny oval sacs at the end of the axon to release chemicals called
a. effectors
b. neurotransmitters
c. stimulants
d. ions

b. neurotransmitters

Explanation:

Neurotransmitters are chemical substances released by axons that are the terminal parts of neurons, neurotransmitters are stored in membrane-bound synoptic vesicles at axon terminals. The neurotransmitter discharge happens when a nerve impulse reaches the end of the axons