1. Exam #3 W 4/7 in class (bring cheat sheet) before Exam #3: the nervous system, movement, and the immune system

2. Fig 45.3 Neurons: cells specialized for transmitting signals

3. Neurons: signals move through neurons electrically and between neurons chemically

4. Fig 45.11 the Na + /K + pump reestablishes the resting state

5. Depolarization of one part of the membrane opens Na + channels further along so the signal travels from one end to the other Fig 48.11

6. Neurons: signals move through neurons electrically and between neurons chemically

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

8. Fig 48.15 At the end of the neuron, neurotransmitters are released signaling the next neuron to depolarize

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

10. Fig 48.14 Neurons are commonly connected to many other neurons, and the effect of the different incoming signals determines what the neuron will do.

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

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

13. Fig 48.12 Sensory and motor neurons are often myelinated

14. Fig 48.13 Myelination allows faster movement of the action potential

15. Fig 48.3 Nerves allow us to perceive the environment while the brain integrates the incoming signals to determine an appropriate response. Response

16. Nervous System Signaling Stimulus Transduction Transmission Response Integration

17. Fig 50.2 This stretch sensitive neuron transduces different signals depending on the amplitude of the stimulus

18. Smells are detected by receptor neurons in our nose. Each receptor is sensitive to a different chemical Fig 50.15

19. Fig 50.18 Light is detected in the eye by receptors on the retina

20. Fig 50.19 Some vision problems arise from misshapen eyeballs too long too short

21. AAL 42.10

22. Light receptor neurons of the eye: Rods detect black and white Cones detect colors…one type of cone for each color - red, blue, and green

23. Fig 50.22 Inhibitory neuro- transmitter No light Membrane depolarized No Signal

24. Fig 50.22 Polar Membrane light No inhibitory neuro- transmitter Signal sent

25. Fig 50.23 Vertebrate retina structure

26. Fig 49.4 The brain and the central nervous system integrate the various incoming signals

27. Fig 48.3 Nerves allow us to perceive the environment while the brain integrates the incoming signals to determine an appropriate response. Response Responses can be release of hormones, change in cell activity, or muscle contraction

28. Muscles allow movement

29. An earthworm: without something to push against, muscles are not much use.

30. The skeleton, made of bones, gives support Fig 50.34

31. Bones (connective tissue) are alive

32. Connections between bones and muscles

33. Fig 50.32 Muscles can only contract. Therefore, two muscles are needed for each range of motion.

34. 2 nerve signals for every movement: excitatory and inhibitory Fig 50.32

35. How do muscles contract?

36. You should watch these animations about neurons: http://www.youtube.com/watch?v=YwN9aCobCy8 http://www.blackwellpublishing.com/matthews/actionp.html http://www.blackwellpublishing.com/matthews/nmj.html And this muscle contraction animation: http://www.blackwellpublishing.com/matthews/myosin.html