Biology Journal 3/11/2014

1. Biology Journal 3/11/2014 What do “excitatory” and “inhibitory” mean? Which of these drugs are excitatory, and which are inhibitory?

2. Biology Journal 3/11/2014 Excitatory = increase neurotransmitters and thus signals Inhibitory = decrease neurotransmitters and thus signals

3. What organs make up the central nervous system? What organs make up the peripheral nervous system?

4. What kind of neuron is A? What kind of neuron is B? What kind of neuron is C? A C B

5. A is a motor neuron because it attaches to a muscle. B is a sensory neuron because it has sensory receptors for dendrites. C is a relay neuron because it connects neurons to other neurons. A C B

6. Label this diagram 4 5 1 6 7 2 3 8

7. Label this diagram Mitochondrion Neurotransmitters Axon terminal Vesicle Transport protein (for reuptake of neurotransmitters) Synapse Dendrite Receptor (for neurotransmitters)

8. What are the effects of cocaineon the synapse? Cocaine blocks dopamine transporter proteins (also known as re-uptake proteins), thus dopamine stays in the synapse, overstimulating the dopamine receptors in the receiving neuron.

9. What are the effects of THC on the synapse? THCreduces the release of dopamine-inhibitors. Thus, lots of dopamine is freely released, causing overstimulation of dopamine receptors. (remember, THC “inhibits the inhibitor of dopamine,” “blocks the blocker,” “shuts down the shutdowner,” etc.)

10. What could be some reasons that drugs like cocaine and methamphetamine are so addictive? These drugs influence dopamine and other neurotransmitters that are involved in feelings of pleasure, calm, and the reward mechanism of the brain.

11. What is the charge inside of an axon when it is polarized? • What is the charge inside of an axon when it is depolarized? • What is the charge inside of an axon when it is repolarized?

12. Polarized: (-) inside axon, (+) outside axon. This is the starting, or “resting” potential. Depolarized: (+) inside axon, (-) outside axon. This occurs when the Na+1 diffuses into the axon. Repolarized: (-) inside axon, (+) outside axon. This happens when the K+1 diffuses out of the axon.

13. Label this neuron cell 8 1 7 2 4 6 3 5

14. Label this neuron cell Axon terminals Dendrites Node of Ranvier Cell body (soma) Myelin sheath Schwann cell Nucleus Axon

15. When does the inside of an axon have a negative charge? (write all correct letters) A. When it is polarized B. When it is depolarized C. When it is repolarized D. Resting potential E. After sodium diffuses in F. After potassium diffuses out G. After the Na/K pump has reset the ions following an action potential A C DFG

16. Which parts of an action potential involve passive transport? A. When Na enters the neuron B. When K leaves the neuron C. When the Na/K pump is moving ions D. Depolarization F. The reuptake of neurotransmitters by transport proteins G. The exocytosis of neuro-transmitters into the synapse ABD

17. What step on the graph… is the resting potential? does Na diffuse into the neuron? is repolarization? does the Na/K pump re-position the ions? is the inside of the axon positive? 0 1 4 5 2 and/or 3

18. What does the myelin sheath do for a neuron? The myelin sheath speeds up and protectsthe electrical signal (action potential)