1. Nervous System
Ch 28, Sections

2. Which type of immune response is always disadvantageous to a person?
A) cell-mediated
B) inflammatory
C) humoral-mediated
D) autoimmune
E) All immune responses are advantageous.

3. 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)

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

5. Neurons come in 3 basic types: Sensory neuron, Interneuron, Motor

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

7. 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

8. The synapse is the connection point between neurons

9. 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

10. 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

11. Ion channels in synapses generate electric current

12. At rest, neurons are low in sodium, high in potassium

13. 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

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

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

16. 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.  

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

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

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

20. Nerve impulse Synopsis: 1. Neuron at rest, -70mV

21. 2. Opening of gated sodium channels depolarizes the cell

22. 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.

23. 4-5. Potassium (K+) channels hyperpolarize the cell behind the action potential

24. 3.5: The impulse is propagated down the axon
In between the Schwann cell ,myelin, Na+ channels open
The action potential moves cown the cell rapidly

25. 6. Depolarization at the axon terminal causes vesicle fusion with membrane
Vesicles contain neurotransmitter
Neurotransmitter is released into the synapse, stimulating the receiving neuron
Stiumuls is terminated by ruptake or destruction of the neurotransmitter

26. 0.5: Vesicles were marched down the axon previously by kinesin

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

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

29. The reflex arc is the most basic neural circuit

30. The Ganglion splits the signal to notify the brain

31. What causes the signal that crosses a synapse to stop?  
A) A second action potential traveling down the signaling cell sounds a sort of "retreat," and the ions reverse direction.  
B) The responding cell runs out of sodium and is no longer able to respond to the stimulus.  
C) The responding cell runs out of potassium and is no longer able to respond to the stimulus.  
D) The chemically gated ion channels of the receiving cell's membrane can only transport for a short period of time before they close.  
E) The neurotransmitter is broken down or transported back to the signaling cell.  

32. Once the threshold potential is reached  
A) the membrane potential is positive.  
B) K+ channels open.  
C) Na+ channels close.  
D) an action potential is inevitable.  
E) None of the choices are correct.  

33. The human brain has 3 major regions

34. Higher thought is compartmentalized to the cerebrum

35. Regions of the cerebral cortex are themselves compartmentalized

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

37. 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

38. Which of the following neurotransmitters is associated neuromuscular junctions?  
A) acetylcholine  
B) GABA  
C) epinephrine  
D) serotonin  
E) endorphins