Bryant-Nervous System

4. Transmitter that activates 2nd messenger system.
7. A brief period during a spike in which a second spike cannot be generated.
8. The nervous system where fibers innervate smooth muscle, cardiac muscle, and glands.
9. Gaps in myelin insulation containing high densities of voltage-gated Na+ and K+ channels.
12. What is the type of synapse where the chemical messenger transmits information one way across a space separating the two neurons?
14. An outer shell of gray matter covering an inner core of white matter.
15. The nervous system where the fibers of the motor neurons supply skeletal muscles.
16. The synaptic input of many neurons to one neuron.
18. Action potentials propagate when locally generated depolarizing current spreads to adjacent regions of membrane causing it to depolarize.
19. What kind of potential is spread by passive current flow and dies out over short distances?
21. Made up of multiple proteins called connexins.
23. Permit ions to flow down concentration gradients.
24. Blocks the degradation of ACh.
26. What kind of target can be a muscle, gland, or another neuron?

1. Blocks vesicular fusion. Blocks the reuptake of serotonin.
2. Change in membrane polarization to more negative values than the rest.
3. Myelin-forming glial cells in the central nervous system.
5. What equation describes the equilibrium potential for a particular ion?
6. Myelin-forming glial cells in the peripheral nervous system.
10. The synaptic output of one neuron onto many neurons.
11. Once the threshold potential is crossed, depolarization occurs via a positive what?
13. What kind of fluid does the brain float in?
17. What type of axon initiates the signal?
20. Change in membrane polarization to more positive values than the rest.
22. What is the kind of synapse where neurons are connected directly by gap junctions?
25. What kind of conduction has propagation of action potentials in myelinated axons by jumping from node to node?