| A | B |
|---|
| Regulation | the control and coordination of all life activities |
| Receptors | specialized structures that are sensitive to changes in the external and internal environment |
| Neurons | nerve cells |
| Effectors | muscles or glands in which neurons are attached to |
| Impulse | electrochemical message |
| Stimulus | a change in the external or internal environment which initiates an impulse |
| Receptors | structures that are specialized to detect stimuli |
| Dendrites | l Fibers that detect stimuli and generate an impulse toward the cyton |
| Cyton | known as the cell body and contains the nucleus of the 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 |
| What does a receptor receive? | the stimulus and initiates an impulse |
| Sensory neuron | carry impulses from the receptors toward the spinal cord and brain |
| Interneuron | relay impulses from one neuron to another |
| Motor neuron | carry impulses from brain and spinal cord toward the effectors |
| What is an effector? | a muscle or gland |
| Hydra | l Contains no brain or control center, so impulses travel in all directions across a nerve net |
