What are small pockets or sacs located in terminal buttons that contain a neurotransmitter?

What are small pockets or sacs located in terminal buttons that contain a neurotransmitter?

• A. Receptors
• B. Synaptic vesicles
• C. Axon terminals
• D. Dendrites

Answer: (B)

Neurotransmitters are stored in synaptic vesicles, tiny sacs inside the presynaptic terminal (the terminal button). When an action potential arrives, calcium influx triggers these vesicles to fuse with the membrane and release their contents into the synaptic cleft. The released neurotransmitter then binds to receptors on the next neuron, influencing whether that neuron fires. After release, vesicles are recycled for future signaling. Receptors are on the postsynaptic side, axon terminals refer to the presynaptic end in general, and dendrites are the receiving parts of the next neuron—not the small storage sacs.

Neurotransmitters are stored in synaptic vesicles, tiny sacs inside the presynaptic terminal (the terminal button). When an action potential arrives, calcium influx triggers these vesicles to fuse with the membrane and release their contents into the synaptic cleft. The released neurotransmitter then binds to receptors on the next neuron, influencing whether that neuron fires. After release, vesicles are recycled for future signaling. Receptors are on the postsynaptic side, axon terminals refer to the presynaptic end in general, and dendrites are the receiving parts of the next neuron—not the small storage sacs.