1. NERVOUS SYSTEM AND ACTIVE TRANSPORT Big Ideas: #2 (Homeostasis) & #4 (Interactions)

2. Basic Organization of the Nervous System

3. Organization of the Brain

4. Nervous Tissue

5. Functional Unit: Neuron

6. Communication Sequence

7. Potential in a neuron

8. What allows for the potential difference? The sodium potassium pump uses ATP to maintain a charge differential inside and outside the neuron

9. Mechanism for the Sodium Potassium Exchange Pump Active Transport Requires ATP Movement against the concentration gradient.

10. Role of facilitated diffusion Movement of ions through gated channels is “down the concentrat ion gradient” or passive

11. Action potential: The change in charge that propagates down a nerve cell and allows signals to travel over long distances. Watch the action potential animation. http://outreach.mcb.harvard.edu/animations/actionpotential_short.s wf http://outreach.mcb.harvard.edu/animations/actionpotential_short.s wf While you are watching the animation, draw a nerve impulse and identify the changes that cause the impulse to occur.

12. Action potential graph:

13. Propagation down an axon

14. Channels are concentrated in nodes of Ranvier

15. What happens when the signal gets to the end? Signal must cross a space (synapse) between: 2 neurons A neuron and a muscle cell Signal changes: Electrical  Chemical  Electrical

16. To prepare for the next lecture: Sketch and label a drawing of a basic nerve synapse.