| A | B |
|---|
| Regulation | l Is the control and coordination of all life activities |
| Receptors | Are specialized structures that are sensitive to changes in the external and internal environment |
| Neurons | Are nerve cells |
| neuron | basic unit of structure and function in the nervous system |
| Nerve control | l Neurons are used for the transmission of impulses from one part of the body to another |
| Impulse | electrochemical message |
| Stimulus | is 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, Contains the nucleus of the neuron. |
| Axon | 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 | the gap between the terminial branches that aid in the transmission of an impulse accros the synapse |
| Neurotransmitters | l Chemicals secreted by the terminal branches that aid in the transmission of an impulse across the synapse |
| Receptor | receives 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 |
| Effector | is a muscle or gland |
| Hydra | Contains no brain or control center, so impulses travel in all directions across a nerve net |
