1. Exam #3 W 4/2 in class Review T 4/1 from 5-7pm in PAI 3.02 Before Exam #3: the nervous system, movement and the immune system

2. Two ways to think about the world: atoms molecules organelles cells tissues organs systems organisms environment Reductionism

3. Two ways to think about the world: atoms molecules organelles cells tissues organs systems organisms environment Reductionism Wholism

4. Sensing and reacting to the environment is critical

5. Failure to properly sense and react to the environment can be fatal

6. CB 48.3 Nerves allow us to perceive the environment while the brain integrates the incoming signals to determine an appropriate response.

7. CB 48.5 Neurons: cells specialized for transmitting signals

8. Axon Parts of a neuron Signals

9. CB 48.7 In the brain neurons are shorter and highly interconnected

10. CB 48.5 Neurons: signals move through neurons electrically and between neurons chemically

11. Nervous System Signaling Stimulus Transduction Response

12. Na + /K + pump plasma membrane Na + K+K+ ATP–>ADP CB 48.10 Ionic gradients in neurons

13. CB 48.13 At rest, the Na + /K + gradient is maintained

14. CB 48.13 Depolarization occurs with the opening of Na + channels

15. CB 48.13 An action potential starts when the local depolarization causes other Na + channels to open

16. CB 48.12 Action potentials only occur when the initial depolarization is above the threshold

17. CB 48.13 An action potential starts when the local depolarization causes other Na + channels to open

18. CB 48.13 Repolarization is achieved via closing Na + and opening K + channels

19. CB 48.13 the Na + /K + pump reestablishes the resting state

20. Depolarization of one part of the membrane opens Na + channels further along so the signal travels from one end to the other CB 48.14

21. CB 48.8 Myelination: allows the depolarization to travel faster

22. CB 48.15 Myelination: allows the depolarization to travel faster…it jumps

23. CB 48.5 Neurons: signals move through neurons electrically and between neurons chemically

24. CB 48.17 At the end of the neuron, neurotransmitters are released signaling the next neuron to depolarize

25. Neurotransmitters can be excitatory or inhibitory (+) (–) (+) (+/–) (–) CB tbl 48.1

26. electrical at synapse chemical At the synapse the electrical signal is converted to a chemical signal

27. CB 48.16 Neurons are commonly connected to many other neurons, and the effect of the different incoming signals determines what the neuron will do.

28. CB 48.18 Neurons are commonly connected to many other neurons, and the effect of the different incoming signals determines what the neuron will do.

29. Incoming signals move through neurons. Only signals above the threshold are transmitted along the neuron.

30. Neuron videos: http://www.youtube.com/watch?v=YwN9aCobCy8 http://www.blackwellpublishing.com/matthews/actionp.html http://www.blackwellpublishing.com/matthews/nmj.html

31. CB 48.19 The brain and the central nervous system integrate the various incoming signals