1. Non-Neuronal Cells of the Nervous System Neuroglia Can’t generate or transmit nerve impulses (signals)

2. Non-Neuronal Cells of the Nervous System

3. 1) Astrocytes Provides neurons with nutrients & energy Physical support Forms the “Blood:Brain Barrier” Central Nervous System (4 kinds of cells)

4. 2) Oligodendrocytes Secretes myelin sheaths around the axon of the neurons (this directs impulse)

5. 3) Microglia Are like Macrophages Scavenge cell debris Protects from pathogens in the brain

6. 4) Ependymal Cells Line the hollow cavities (ventricles) Secretes cerebral & spinal fluid which acts as ‘shock absorber’, and distributes nutrients in the brain and spinal cord

7. Central Nervous System

8. Peripheral Nervous System A myelin system Protects cells

10. Transmission Of the Nerve Impulse

11. Page 399 Synapse (2 cells) Before arrival of an Action (Electric) Potential

12. Action Potential opens channels that cause Calcium ions to move into the Synaptic Bulb

13. Vesicles fuse to the Synaptic Membrane

14. Neurotransmitters released into ‘cleft’ Examples: Glutamate (most common in brain) Gamma-aminobutyric acid (GABA) Dopamine Acetylcholine Epinephrine Histamine Serotonin Neurotensin Nitric Oxide Neuropeptide Y

15. Neurotransmitters bind to receptors in next neuron...opening Sodium channels. This initiates an Action Potential in the next Neuron.

16. Neurotransmitters are cleared out of cleft. By: Diffusion Reuptake by upper neuron Enzymatic breakdown