The rounded areas on the end of the axon terminals are called the

The rounded areas on the end of the axon terminals are called the

• A. Terminal branches
• B. Synaptic knob
• C. Schwann cell nucleus
• D. Choroid coat

Answer: (B)

The rounded end of the axon terminal is the synaptic knob. This knob is the specialized swelling that forms the synapse with the next neuron or an effector cell, and it houses tiny vesicles filled with neurotransmitters. When an action potential arrives, calcium triggers these vesicles to fuse with the membrane and release neurotransmitters into the synaptic cleft, transmitting the signal onward. The other terms don’t describe this specific end-region: terminal branches are the small divisions at the end of the axon before reaching the synapse; Schwann cell nucleus is the nucleus of a glial cell that insulates peripheral nerves; and the choroid coat is a vascular layer of the eye.

The rounded end of the axon terminal is the synaptic knob. This knob is the specialized swelling that forms the synapse with the next neuron or an effector cell, and it houses tiny vesicles filled with neurotransmitters. When an action potential arrives, calcium triggers these vesicles to fuse with the membrane and release neurotransmitters into the synaptic cleft, transmitting the signal onward. The other terms don’t describe this specific end-region: terminal branches are the small divisions at the end of the axon before reaching the synapse; Schwann cell nucleus is the nucleus of a glial cell that insulates peripheral nerves; and the choroid coat is a vascular layer of the eye.