The neuron
Label the following terms: Soma Dendrite Schwaan cell Axon terminal Nucleus Myelin sheath Axon Node of Ranvier
Neuron Vocabulary You must know the definitions of these terms
1. Synaptic Cleft
2. Neuron
3. Impulse
5. Motor Neuron
6. Interneuron
7. Body (Soma)
8. Dendrite
9. Axon
10. Action Potential
11. Myelin Sheath (Myelin)
12. Afferent Neuron
13. Threshold
14. Neurotransmitter
15. Efferent Neurons
16. Axon Terminal
17. Stimulus
18. Refractory Period
19. Schwann
20. Nodes of Ranvier
21. Acetylcholine
STEPS IN THE ACTION POTENTIAL 1. The presynaptic neuron sends neurotransmitters to postsynaptic neuron. 2. Neurotransmitters bind to receptors on the postsynaptic cell. - This action will either excite or inhibit the postsynaptic cell. - The soma becomes more positive. 3. The positive charge reaches the axon hillock. - Once the threshold of excitation is reached the neuron will fire an action potential. 4. Na+ channels open and Na+ is forced into the cell by the concentration gradient and the electrical gradient. - The neuron begins to depolarize. 5. The K+ channels open and K+ is forced out of the cell by the concentration gradient and the electrical gradient. - The neuron is depolarized. 6. The Na+ channels close at the peak of the action potential. - The neuron starts to repolarize. 7. The K+ channels close, but they close slowly and K+ leaks out. 8. The terminal buttons release neurotransmitter to the postsynaptic neuron. 9. The resting potential is overshot and the neuron falls to a -90mV (hyperpolarizes). - The neuron continues to repolarize. 10. The neuron returns to resting potential. The Synapse
Label the following terms: Pre-synaptic membrane Neurotransmitters Post-synaptic membrane Synaptic cleft Vesicle Post-synaptic receptors