| A | B |
|---|
| Regulation | Control and coordination of activities |
| Receptors | Are specialized structures that are sensitive to changes in the external and internal environment |
| Neurons | nerve cells |
| Effectors | l Are muscles or glands in which neurons are attached to |
| Impulse | electrochemical message |
| Stimulus | is a change in the external or internal environment which initiates an impulse. |
| Dendrites | l Fibers that detect stimuli and generate an impulse toward the cyton |
| Cyton | cell body, nucleus of neuron |
| Axon | l A fiber that transmits the impulse away from the cyton and towards the terminal branches |
| Terminal Branches | l The ends of axons that secrete neurotransmitters |
| Synapse | l The gap between the terminal branches of 1 neuron and the dendrites of another neuron. |
| Neurotransmitters | l Chemicals secreted by the terminal branches that aid in the transmission of an impulse across the synapse |
| Reflex Arc | path of an impulse |
| Hydra | l Contains no brain or control center, so impulses travel in all directions across a nerve net |
| Recepters, Neurons and Effectors | 3 basic structures of the Nervous System |
