1. What are the functions of the Nervous System? _____ ________ (environment & self) Conduct ________ _________ & __________ impulses (stimuli) __________ BIOL 2010 Human Anatomy & Physiology I

2. What are the functions of the Nervous System? Out of this comes _________, & ability to ___________

3. How is the Nervous System organized? ________ ______ _____ ________ ______ _____ Central Nervous System (CNS) Peripheral Nervous System (PNS) 43: ( ___ cranial & ___ spinal nerves)

4. How is the Nervous System organized? CNS ____ Afferent _________ Somatic ____________ Sympathetic _____________

5. What are the Structural/functional units of the Nervous System? Nerve cells ~ _______ Maintaining cells ~ ______ ______ Neuron anatomy: ___________________ ____________ _________

6. What are the different types of Neurons? Structural types: ________ ______ ________ Functional types: Association ~ Interneurons Afferent ~ Sensory neurons Efferent ~ Motor neurons

7. What are the types of glial cells and what tasks do they accomplish? ___________: control substances entering/leaving CSF Associated with _______________ which is formed by endothelial cells of blood vessels.

8. _______________: Line the ventricles (cavities) of CNS, create cerebral spinal fluid and aid in its circulation. What are the types of glial cells and what tasks do they accomplish?

9. _____________: Small specialized macrophages that are attracted to areas of damage in the CNS and phagocytize debris What are the types of glial cells and what tasks do they accomplish?

10. ________________: Cells in the CNS that have multiple extensions that wrap around multiple axons forming myelin sheaths. What are the types of glial cells and what tasks do they accomplish?

11. _______________: Cells in the PNS that wrap around single axons forming myelin sheaths. The gaps in between Schwann cells are called ______ __ ___________ What are the types of glial cells and what tasks do they accomplish?

12. What are the differences between Myelinated and Unmyelinated Neurons? _______________: Action potential occurs along entire plasma membrane… ________ _______________: Action potentials jump from one node to the next… _________

13. What is Saltatory Conduction and why is it important? Thick myelin sheaths insulate plasma membrane and force “jumping” (__________) movement of electrical charge (action potential) ____________ effects myelin sheaths in CNS

14. How can you tell if nervous tissue is myelinated? Myelin sheaths contribute to white appearance = _____ _________ Neuron cell bodies and dendrites contribute to a darker color = _______ __________ Clusters of cell bodies are called _______ or _____ in the PNS and the CNS respectively

15. How are signals sent along the axon highway? Make sure you are comfortable with: Establishment of resting potentials Formation and propagation of action potentials. Mechanisms involved with conducting action potentials between cells (Intercellular action potential propagation).

16. Electric signals (called _______________) are essential to nerve cell function and muscle contraction. Refer to tables 11.2, 3 & 4 BI 201 Human Anatomy & Physiology How does the body generate electric potential?

17. _________ with “-” charge stuck inside cells __________ channels that allow K+ to diffuse in or out of the cell Very few Na+ ions can diffuse through cell membrane EXCEPT via _____________ ___________ contributes to gradient Gated Non-gated BI 201 Human Anatomy & Physiology How does the body maintain electrical gradients?

18. As K+ diffuse out they leave ____________ inside the cell and develop an electric potential. When the “-” attraction inside the cell is = to the tendency for K+ to leave then __________ is established. Usually around -70 to -90 mVolts… called _______ ___________ BI 201 Human Anatomy & Physiology How does the body maintain electrical gradients?

19. 1) 2) What are the 2 primary ways to change the resting potential? Decrease potential… _____________ (hypopolarization) Increase potential… _____________ BI 201 Human Anatomy & Physiology

20. What would the effect on the resting membrane potential be if the permeability of the plasma membrane to K+ was reduced? Why? BI 201 Human Anatomy & Physiology Take 5!!! Discuss with your neighbor and predict an answer.

21. What is the effect on the resting potential that results from changing Na+ concentrations? Change in Na+ ion concentration DOESN”T have much effect Change in permeability DOES Why? BI 201 Human Anatomy & Physiology

22. Cells such as muscle and nerve cells have >#... What properties make some cells electrically excitable? Depolarization causes the ___ channels to open quickly… (___ open more slowly and close more slowly)

23. What about the effects of Ca 2+ ions on the resting potential? When extracellular Ca2+ ions are reduced then they _________ _____ ______ (including gated Na+ channels, which causes them to open). What is the result of Hypocalcemia? BI 201 Human Anatomy & Physiology Ca 2+

24. A localized stimulus usually causes… a _____ _______ (change in resting membrane potential). Can be caused by: 1) 2) 3) 4) 5) BI 201 Human Anatomy & Physiology Are there any potentials other than resting potentials?

25. Changes in the resting potential can be at different levels of magnitude, i.e. ________ Influence of local potentials can be increased by ___________ BI 201 Human Anatomy & Physiology What are the properties of local potentials? Local potentials taper off as they move away from the stimulus source (see table 11.3)

26. If the threshold potential is reached… then an _______ _________ results These are propagated along the plasma membrane and are “_____________” 3 phases: Below the threshold = local potential ~ “______” Above the threshold = action ~ “______” BI 201 Human Anatomy & Physiology Do local potentials have any potential? (see table 11.4)

27. BI 201 Human Anatomy & Physiology How do those waves correlate with cellular reality?

28. What happens after all the excitement? Refractory period Until the voltage gated channels return to the resting state, no further action potential is possible. When totally insensitive…then ________ __________ _________ BI 201 Human Anatomy & Physiology

29. How do action potentials move along a cell? What keeps the action potential from reversing direction?

30. What about getting the electrical “message” (action potential) to the next cell? Generally accomplished via _________ _________ If ligand opens Na+ channels then… If ligand opens K+ channels then… BI 201 Human Anatomy & Physiology

31. Cardiac & smooth muscle tissue have _________ ____________. Action potentials can be propagated across adjacent cells via the ___ _________, which allow ions to pass through. BI 201 Human Anatomy & Physiology What about getting the electrical “message” (action potential) to the next cell?

32. Some neurons will continue to maintain a local potential sufficient to initiate action potentials. other neurons begin to become insensitive to continued stimulus and the frequency drops off until the local potential drops below threshold (_____________). BI 201 Human Anatomy & Physiology Do all neurons respond to continued stimulation equally?

33. How are signals sent along the axon highway? In addition to neurotransmitters, there are also ________________ (w/c influence _________ of pre- or post-synaptic membrane) Example: ___________, w/c when bound w/ receptors on pre-synaptic neurons limit neurotransmitter release (see table 11.5)

34. What is the difference between Excitatory & Inhibitory neurons? Ligands binding with post- synaptic receptors can cause: A _____________ in postsynaptic membrane potential (_________ ~ closer to zero… depolarization) Example: ___ ~ opens Na + channels An __________ in postsynaptic membrane potential (_________ ~ further from zero…hyperpolarized) Example: ________ ~ opens Cl - channels

35. Action potentials in pre-synaptic terminal don’t always result in an action potential on the postsynaptic membrane… ________ ___________________ __________ Are action potentials always propagated between cells?

36. Different action potentials from varying neurons can simultaneously influence the neuron they collectively synapse with to create ________ ___________ Are action potentials always propagated between cells?

37. Reflexes and Pathways ___________ How are reflexes and pathways integrated?

38. Can nervous tissue recover from injury? Why would the portion of an axon severed from the neuron cell body die? If a nerve is cut, the ____ ______ and _____ _______ are phagocytized. However, the Schwann cell bodies remain. The proximal axon “________” for reconnection If it encounters ________ _____ then it grows inside this pathway to re-innervate the organ (muscle) Why would this not readily occur in the CNS?