1. Neurons- The matter of the nervous system
Chapter 7: Pgs

2. The Nervous system controls the entire body
It is the interface between stimulus and response
Allows animals to interact with their environment
Brain and spinal cord: central nervous system (CNS)
Other nerves: peripheral nervous system (PNS)

3. The nervous system is the interface between stimulus and response

4. The Neuron is the base unit of the nervous system

5. Neurons are large cells supported by a variety of glial cells
Human neurons can be 1m in length
Potentially thousands of glial cells support a single neuron
Provide nutrition, support, insulation
Schwann cells are an example

6. Schwann cells are glial cells which protect neurons with myelin

7. The 3 kinds of neurons work together to interface between stimulus and response
The reflex arc is the simplest neural circuit
Consists of
1 sensory neuron
1 interneuron
1 motor neuron

8. The synapse is the connection point between neurons
Vesicles sit in axon terminals, loaded with neurotransmitters

9. Some important neurotransmitters
Acetylcholine- Neuromuscular
Dopamine-Exitatory
Norepinephrine
GABA- Inhibitory
Serotonin-Regulatory

10. Many Drugs copy the action of neurotransmitters
Methamphetamine is structurally similar to dopamine
Dopamine involved in learning and reward systems
Dopamine
Methamphetamine

11. Many synapses make complex information processing possible
Cell interactions form logic circuits
AND, NOT, etc. gates are formable
Human Brain: 100 billion neurons
Up to 10,000 synaptic connections/neuron

12. Which one of the following statements is false?
A) Sensory neurons convey signals from the CNS to sensory receptors.  
B) Motor neurons convey signals from the CNS to effector cells.  
C) Interneurons integrate data and relay appropriate signals to other interneurons or to motor neurons.  
D) The PNS includes nerves and ganglia.  
E) The CNS consists of the brain and spinal cord.  

13. The Nerve impulse

14. The nervous system runs on electricity
Current- The movement of charge (electrons or ions)
Voltage- potential energy stored in a charge disparity over distance
Nervous system uses ions (Na+, K+, Cl-, Ca++) to send signals from one neuron to another

15. At rest, neurons must be ready to respond in milliseconds
Charge and concentration gradients hold potential chemical energy
Water behind a dam is stored potential energy

16. Neurons have a resting membrane potential
Negatively charged
Keeps the neuron poised for instant action
-70mV
Maintained by constant active transport of ions

17. Pumps maintain gradients, channels activate cells

18. Which of the following statements about the sodium-potassium pump is false?  
A) It is a membrane protein.  
B) It keeps the concentration of sodium low inside the cell.  
C) It moves sodium across the membrane and into the cell.  
D) It helps maintain the resting membrane potential.  
E) It actively transports potassium into the cell

19. Two kinds of ion channels
Ligand-gated ion channels open when bound to a ligand (a neurotransmitter)
Voltage gated ion channels open when the voltage in the cell changes

20. Neurons can respond in milliseconds, giving us quick reflexes

21. Neurotransmitters are the chemical signals with which neurons communicate across a synapse
Neurotransmitters bind to gated ion channels in the cell membrane of the next neuron
Binding opens the ion channel
Hydrolysis or reuptake removes the neurotransmitter

22. The Nerve Impulse step by step

23. Step 1- depolarization causes vesicles to fuse

24. Step 2- Fused vesicles release neurotransmitter into the synapse

25. Step 3- Neurotransmitters open gated sodium channels, depolarizing cell

26. Step 5- Voltage-gated sodium channels pass the signal down the axon

27. Voltage-gated channels sit at nodes of Ranvier, making the signal travel faster

28. Step 6- Change in voltage at the axon terminal passes the signal on

29. Step 7- Potassium channels are opened, re-polarizing the cell for its next response

30. Step 8- Ion balance is restored using active transport- the Na+/K+ pump

31. What is the functional unit of the nervous system?
A) dendrite  
B) cell body  
C) neuron  
D) axon  
E) synapse  

32. Depolarization is the activation event
Depolarization is caused by opening of gated sodium channels
When depolarized, neurons respond in milliseconds

33. Action potentials normally travel along an axon
A) toward the cell body.  
B) away from the cell body.  
C) in either direction, depending on the needs of the animal.  
D) away from the synapse.  
E) from axons into dendrites.

34. Step 0.5: Vesicles were marched down the axon previously by kinesin

35. Antidepressants can block reuptake of neurotransmitters
SSRI- “Selective Serotonin Reuptake Inhibitors”
Prozac, Paxil, Zoloft, etc.- all SSRI’s

36. Sarin nerve gas is an Acetylcholinesterase Inhibitor
How does it work?
How does it kill people?

37. The reflex arc is the most basic neural circuit

38. The Ganglion splits the signal to notify the brain

39. The human brain has 3 major regions

40. Higher thought is compartmentalized to the cerebrum

41. Regions of the cerebral cortex are themselves compartmentalized

42. A homonculus shows the area of the brain devoted to regions of the body