1. AIM: How does the Nervous System work and how does it help the body maintain homeostasis?
DO NOW: What is the function of the nervous system? What are the three types of neurons? What are their functions?
Nervous System Vocabulary: neuron, cell body (soma), axon, dendrites, myelin sheath, synapse, neurotransmitter, receptor, central nervous system, peripheral nervous system, stimulus, impulse, regulation, effector, action potential, membrane (resting) potential, depolarization
Have out HW for me to check
Results and Discussion section due via turnitin.com on 12/23 (extended)
HW due Tuesday pg 900 questions 1-5 and pg 905 ques 5
Exam on Wednesday circulation, respiration and the nervous system

2. Function of the Nervous System
Process Information
Stores Information
Controls Voluntary movements
Controls Involuntary process and actions
Stimulus Vs Response

3. Parts of the Nervous System
Central Nervous System
Brain
Spinal Cord
Peripheral Nervous System
Autonomic Nervous System
Somatic Nervous System

4. What is Regulation? Control and coordination of all life functions
2 systems involved
Stimulus: change or activity in the environment that causes a change in the organism; physical, chemical
Receptors
Response: action or movement resulting from a stimulus
Effectors
Impulses: electrical messages sent over a nerve cell (neuron)

5. Aim: How is an action potential propagated in the nervous system?
Do Now: What is the central nervous system? Distinguish between sensory, motor and interneurons
Results and Discussion section due via turnitin.com on 12/23 (extended)
HW due Tomorrow pg 900 questions 1-5 and pg 905 ques 5
Exam on Wednesday circulation, respiration and the nervous system

6. Review of Do Now Central Nervous System Sensory Neurons Motor Neurons
Brain and spinal cord
Sensory Neurons
Carry signals betewen the central nervous system and a sense organ.
Motor Neurons
Carry signals between the central nervous system and a muscle
Interneurons
Carry signals between sensory and motor neurons
Demyelination

7. Neuron
Sketch the diagram of a neuron below, and label each part AND its function.
(See page 897)
What would you expect to happen if a person had a disease in which the myelin sheath is destroyed?
Sensory, motor, interneurons
Axon terminals
Myelin sheath
Nodes
Cell body
Axon
Nucleus
Dendrites

8. Membrane Potential
Describe the difference in charge between the inside and outside of the nerve cell (a).
How is this difference maintained? Explain based on the picture above (b). Be specific!

9. Follow-up Questions
Why is it impossible for ions to travel across the membrane by simple diffusion? How do ions travel across the cell membrane (two ways)?
What do you think would happen if the sodium channels in a nerve cell were suddenly opened? The potassium channels?
What effect would each of these events have on the membrane potential?

10. Aim: How is an action potential propagated in a neuron
Do Now: How does an influx of Na+ change the membrane potential? What about an influx of K+?
Have out HW
Test on Thursday

11. The Action Potential
Aim: How is an action potential propagated in the nervous system?

12. Cool Neuroscience Animation!

13. Review Questions
How does an action potential stop, i.e., how does a nerve cell return to its resting (membrane) potential?
Why is an action potential an all or none event?
If action potentials are all or none events, how does the nervous system distinguish between strong and weak stimuli?

14. The Action Potential
Resting potential established by Sodium Potassium pump
Sodium-potassium pump
(3 Na+ out, 2 K+ in)
Stimulation: Channels open Na+ in and K+ out
Threshold
Reversal of charges
All or none event
Like the Domino effect

15. Dendrite of adjacent neuron
The Synapse
Direction of Impulse
Dendrite of adjacent neuron
-Junction between axon of one neuron and dendrites of another
-Neuron can transfer an impulse to another cell
How would abnormal levels of neurotransmitters affect the function of the nervous system?
Axon
Receptor
Vesicle
Electrical vs. Chemical Signaling
Axon terminal
Synaptic cleft
Neurotransmitter

16. Questions For Review
How does the nervous system couple electrical and chemical signaling? What events take place at the junction between two neurons?
What is an action potential?
Define depolarization.
How does a neuron distinguish between a strong stimulus and a really strong stimulus?
What is a synapse? What type of signaling takes place at the synapse?