1. Nerve Cell Structure and Function
Interactions
Nerve Cell Structure and Function

2. Opener What’s the key information in the question?
Which two can you eliminate right away? Why?
Which one seems right, but isn’t? Why?
FIVE MINUTES
Answer is D

3. Agenda Grade practice FRQ Notes:
Nerve Cells: How they work, and why we love them. . .
Next class how nerve cells communicate with one another
Homework: Read Ch and add to the notes we are taking in class

4. Learning Target
I can explain how the parts of a nerve cell work together to receive, transmit and send a message

5. Practice FRQ
Put a number by where you got points on the two practice FRQ’s
Total the numbers at the top of your paper out of 13

6. Dendrites
Axon
Axon
Terminals
Cell Body

8. Nerve Cells Also called neurons
Receive and transmit information through a combination of chemical and electrical signals

9. The Action Potential
The transmission of an electrical impulse through a nerve cell
How nerve cells send “messages” to each other and other cells
Depends on THREE key transport proteins:
Sodium/Potassium Pump
Voltage-gated Na+ channel
Voltage-gated K+ channel

11. Resting Potential Transport Proteins maintain: Protein state:
Concentration gradient
Electrical gradient
Protein state:
Na+ gate closed
K+ gate open
Inside cell:
Negative (-) Charge
Outside cell:
Positive
More Na+ ions

12. Step 1: Depolarization Stimulus received by Neuron
Na+
Stimulus received by Neuron
Voltage Gated Na+ Channels in cell membrane OPEN
Na+ moves into cell DOWN concentration gradient
K+ channels CLOSED K+
Na+ Channel
Cell
Membrane
Cell
K+ Channel

13. Result The charge polarity (+/-) is REVERSED Inside of cell +
Outside of cell -

14. Step 2: repolarization Voltage Gated Na+ Channels Close K+ OPEN
K+ moves OUT of the cell, RESTABLISHING the resting potential charge difference K+
Na+ Channel
Cell
Membrane
Cell
K+ Channel

15. The Na+/K+ Pump helps restore ion balance
STEP 3
The Na+/K+ Pump helps restore ion balance

17. Step 4 The action potential travels down axon
Steps 1-3 are repeated multiple times

18. Sodium channels close but K+ still open to return to resting state
Step 5
Sodium channels close but K+ still open to return to resting state

20. What happens next?
The signal can be TRANSMITTED to another nerve cell at the SYNAPSE
OR the signale can result in an action by another cell type (MUSCLE cell, for example)

21. Action Potential: Mr Anderson Action Potential Book