6.a&p i nervous system2010


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6.a&p i nervous system2010

  1. 1. Unit III- Nervous System <ul><li>Marieb, 8th Edition </li></ul><ul><ul><li>Chaps 11-12; skim 14 </li></ul></ul><ul><ul><li>pages 385-483; 491-493, 510- 519 skim; skim 525-539 </li></ul></ul><ul><ul><li>Book and CD-ROM </li></ul></ul><ul><li>CD-ROMS in SLC Rm 1214 </li></ul>
  2. 4. <ul><li>Nervous System </li></ul><ul><li>I. A. Introduction </li></ul><ul><ul><li>1. Homeostasis - maintain internal life functions within a normal range </li></ul></ul><ul><ul><li>2. Communication an important component </li></ul></ul><ul><ul><ul><li>Detect a problem - sensory system </li></ul></ul></ul><ul><ul><ul><li>Correct the problem with an adjustment </li></ul></ul></ul><ul><ul><ul><li>Communication between two components involves the nervous system and its principles </li></ul></ul></ul>
  3. 5. <ul><li>I. B. Organization of the Nervous System </li></ul><ul><ul><li>1. Central Nervous System (CNS) </li></ul></ul><ul><ul><ul><li>Brain </li></ul></ul></ul><ul><ul><ul><li>Spinal cord </li></ul></ul></ul><ul><ul><li>2. Peripheral Nervous System (PNS) </li></ul></ul><ul><ul><ul><li>a) Somatic Nervous System </li></ul></ul></ul><ul><ul><ul><ul><li>Voluntary system that controls skeletal muscles attached to limbs / bones </li></ul></ul></ul></ul><ul><ul><ul><li>b) Autonomic Nervous System (ANS) </li></ul></ul></ul><ul><ul><ul><ul><li>Involuntary system that controls cardiac and smooth muscles (stomach, uterus, blood vessels, etc.) and glands </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Sympathetic and Parasympathetic Divisions </li></ul></ul></ul></ul>
  4. 6. <ul><li>I. C. Cellular Neuroanatomy </li></ul><ul><ul><li>1. Nerve Cell = Neuron </li></ul></ul><ul><ul><ul><li>Cell body = nucleus, Rough ER, neurotubules, Golgi, etc. </li></ul></ul></ul><ul><ul><ul><li>Dendrites = processes which receive input to cell body </li></ul></ul></ul><ul><ul><ul><li>Axon = longer process which communicates with other neurons </li></ul></ul></ul><ul><ul><ul><li>Terminal Branches / End Terminals = end of axon that communicates with next neuron or muscle or gland </li></ul></ul></ul><ul><ul><li>How can we protect this long axonal process? </li></ul></ul>Fig. 11.4
  5. 7. <ul><li>I. C. Cellular Neuroanatomy </li></ul><ul><ul><li>2. Glial Cells - supportive cells of the CNS </li></ul></ul><ul><ul><ul><li>Protective, metabolic, phagocytosis, transport nutrients & wastes between neurons & blood vessels </li></ul></ul></ul><ul><ul><ul><li>Schwann cells in the PNS and a glial cell in the CNS produce myelin sheath - phospholipids membranes of cell wrapped around neuronal axon, function: </li></ul></ul></ul><ul><ul><ul><ul><li>protection - regeneration </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Speed up rate of conduction down axon (node to node) </li></ul></ul></ul></ul>Fig. 48-5
  6. 8. Fig. 11.3
  7. 9. Fig. 48-5
  8. 10. Fig. 11.5
  9. 11. Fig. 13-4
  10. 12. Fig. 48-4 and Table 11.1
  11. 13. <ul><li>I.C. Cellular Neuroanatomy </li></ul><ul><ul><li>3. Types of Neurons </li></ul></ul><ul><ul><ul><li>a) Sensory / Afferent Neurons - carry information about the environment (internal and external) towards the CNS </li></ul></ul></ul><ul><ul><ul><li>b) Motor / Efferent Neurons - carry information away from the CNS towards the periphery & effectors (muscle or gland) </li></ul></ul></ul><ul><ul><ul><li>c) Interneuron / Association Neurons </li></ul></ul></ul><ul><ul><ul><ul><li>Only within the CNS </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Connect two other neurons together, any combination </li></ul></ul></ul></ul>
  12. 14. Fig. 48-1
  13. 15. <ul><li>I. C. 4. Synapse space or gap between a neuron and a neuron or a neuron and an effector </li></ul><ul><li>I. C. 5. Stimulus Response Mechanism </li></ul><ul><ul><li>a) Stimulus </li></ul></ul><ul><ul><ul><li>Change in the environment </li></ul></ul></ul><ul><ul><li>b) Response </li></ul></ul><ul><ul><ul><li>Reaction by the organism in response to the original stimulus </li></ul></ul></ul><ul><ul><li>c) Basis of all functioning of the nervous system, communication directed at stimulus - response mechanisms basis of behavior, learning, etc. </li></ul></ul>
  14. 16. II. Impulse conduction <ul><li>A. Introduction </li></ul><ul><ul><li>1. 1930s - at Woods Hole Mass., work on the giant squid axon - nonconducting cell </li></ul></ul><ul><ul><ul><li>Large enough to isolate from animal and remove the cellular/axonal cytoplasm and chemically analyze </li></ul></ul></ul>
  15. 17. 1a. Ionic Distribution <ul><li>EXTRACELLULAR INTRACELLULAR </li></ul><ul><li>SODIUM - Na + Na + </li></ul><ul><ul><ul><li>HIGH LOW </li></ul></ul></ul><ul><li>POTASSIUM - K + K + </li></ul><ul><ul><ul><li>LOW HIGH </li></ul></ul></ul><ul><li>CHLORIDE - Cl - Cl - </li></ul><ul><ul><ul><li>HIGH LOW </li></ul></ul></ul><ul><li>HIGH PROTEINS - </li></ul><ul><li>SEMI-PERMEABLE MEMBRANE </li></ul>
  16. 18. 1b. CHANGES BASED UPON NORMAL NET DIFFUSION <ul><li>EXTRACELLULAR INTRACELLULAR </li></ul><ul><li>SODIUM - Na + Na + </li></ul><ul><ul><ul><li>HIGH LOW </li></ul></ul></ul><ul><li>POTASSIUM - K + K + </li></ul><ul><ul><ul><li>LOW HIGH </li></ul></ul></ul><ul><li>CHLORIDE - Cl - Cl - </li></ul><ul><ul><ul><li>HIGH LOW </li></ul></ul></ul><ul><li> HIGH PROTEINS - </li></ul><ul><li>SEMI-PERMEABLE MEMBRANE </li></ul>
  17. 19. 1c. CHANGES BASED UPON NORMAL NET DIFFUSION OPPOSED BY ACTIVE TRANSPORT AND ELECTROSTATIC CHARGES <ul><li>EXTRACELLULAR INTRACELLULAR </li></ul><ul><li>SODIUM - Na + Na + </li></ul><ul><ul><ul><li>HIGH LOW </li></ul></ul></ul><ul><ul><ul><li>PASSIVE </li></ul></ul></ul><ul><ul><ul><li>ACTIVE </li></ul></ul></ul><ul><li>POTASSIUM - K + K + </li></ul><ul><ul><ul><li>LOW HIGH </li></ul></ul></ul><ul><ul><ul><li>PASSIVE </li></ul></ul></ul><ul><ul><ul><li>ACTIVE </li></ul></ul></ul><ul><li>CHLORIDE - Cl - Cl - </li></ul><ul><ul><ul><li>HIGH LOW </li></ul></ul></ul><ul><ul><ul><li>ELECTROSTATIC </li></ul></ul></ul><ul><li>NEGATIVE </li></ul><ul><li> HIGH PROTEINS - </li></ul><ul><li>SEMI-PERMEABLE MEMBRANE </li></ul>
  18. 20. <ul><li>2. Summary of Above Ionic Behaviors </li></ul><ul><li>2a. Against maintaining the neuronal ionic gradient </li></ul><ul><ul><li>Passive diffusion (high to low) </li></ul></ul><ul><li>2b. Favors maintaining the neuronal ionic gradient </li></ul><ul><ul><li>Active transport of the Na + - K + pump </li></ul></ul><ul><ul><li>Electrostatic forces due to intracellular protein negative charge </li></ul></ul><ul><ul><ul><li>Keeps chloride out </li></ul></ul></ul><ul><ul><ul><li>Binds to positive K + to keep intracellular </li></ul></ul></ul>
  19. 21. Figure 48.6 Negative Intracellular Electrical Charge
  20. 22. Fig. 48-7
  21. 24. II. A. 3.Terms: <ul><li>a) potential difference - difference in electrical charge </li></ul><ul><li>b) polarized membrane - potential difference across membrane due to combination of membrane permeability and ionic concentrations </li></ul><ul><li>c) resting potential - non-conducting neuron with a potential difference across the membrane equal to -70 to -90 millivolts (mV) inside compared to outside </li></ul><ul><li>d) action potential or nerve impulse or spike a brief transient change in resting potential </li></ul>
  22. 25. Fig. 48.6 & 11.7 II.B. Action Potential 1. Stimulating and recording setup stimulator
  23. 26. <ul><li>ACTION POTENTIAL </li></ul><ul><li>+ </li></ul><ul><li>- </li></ul><ul><li>-50 </li></ul><ul><li>-70 </li></ul><ul><li> TIME msec </li></ul>2 3 4 5 6 7 8 9 10 0 mV
  24. 27. <ul><li>B. Action Potential </li></ul><ul><ul><li>2. Electrode enters the axon </li></ul></ul><ul><ul><li>3. Excitatory stimulus - below threshold </li></ul></ul><ul><ul><li>4. Threshold stimulus - (outside) sodium gates suddenly open and the Na-K pump OFF </li></ul></ul><ul><ul><li>5. Depolarization - sodium continues to enter past 0mV (loss of polarization) </li></ul></ul><ul><ul><li>6. Sodium inactivation around -35mV as (inside) gate closes - too much positive charge inside </li></ul></ul><ul><ul><li>7. Repolarization - potassium out since Na + gates closed & K + no longer attracted to positive protein </li></ul></ul><ul><ul><li>8. Hyperpolarization - pump actively back on as K + exit overshoots resting potential </li></ul></ul><ul><ul><li>9. Equilibrium or normal resting potential </li></ul></ul><ul><ul><li>10. Inhibitory stimulus - a hyperpolarizing stimulus, harder to excite neuron during this time period </li></ul></ul>
  25. 29. Fig. 11.8
  26. 30. FIG. 48.8, 11.9
  27. 31. FIG. 48.9
  28. 32. FIG. 48.9
  29. 33. FIG. 48.9
  30. 34. FIG. 48.9
  31. 35. FIG. 48.9 or 11.12
  32. 36. <ul><li>11. All - or - Nothing Phenomenon </li></ul><ul><ul><li>Once threshold is reached, no variation in strength of response </li></ul></ul><ul><ul><li>How does stronger stimulus manifest itself? </li></ul></ul><ul><ul><li>Increase in frequency - not change in magnitude or height of action potential </li></ul></ul><ul><li>12. a) Absolute Refractory Period - impossible to stimulate a neuron a second time while the Na - K pump turned off, from threshold to repolarization (while K + moving inwards) </li></ul><ul><ul><li>b) Relative Refractory Period - can stimulate a neuron with a stronger stimulus, to reach threshold, while neuron in hyperpolarization </li></ul></ul>
  33. 37. Fig. 11.13
  34. 38. <ul><li>13. Propagation </li></ul><ul><ul><li>Signal does not die out before reaching the end of the axon, nor does it have to boosted </li></ul></ul><ul><ul><li>Each area act as stimulus for the next portion of the membrane </li></ul></ul><ul><ul><li>Depolarizing region with its positive charge moves into the adjacent negatively charges “sink” </li></ul></ul><ul><ul><li>Why doesn’t action potential go BOTH ways in the axon?? </li></ul></ul>Fig. 48-10 & 11.12
  35. 39. Fig. 11.14
  36. 40. <ul><li>14. Factors influencing conduction velocity </li></ul><ul><ul><li>Size of axon - larger diameter means faster conducting velocity </li></ul></ul><ul><ul><li>Temperature - higher temperature means faster conduction velocity </li></ul></ul><ul><ul><ul><li>Cold block on axon stops conduction </li></ul></ul></ul><ul><ul><li>Myelin sheath faster conduction than non-myelinated axon </li></ul></ul><ul><ul><li>Fig. 11.16 </li></ul></ul>
  37. 42. III. Synaptic Transmission <ul><li>1. Synapse = space or gap between two neurons or a neuron and an effectors (muscle or gland) </li></ul><ul><ul><li>Electrical synapse - smaller gap where electrical charge (action potential) of a neuron jumps the gap to stimulate second neuron (electric eel) </li></ul></ul><ul><ul><li>Chemical synapse - larger space or gap where a chemical diffuses across synapse </li></ul></ul><ul><ul><li>Large number of synapses on a neuron’s cell body and dendrites </li></ul></ul>
  38. 43. Fig. 48-13
  39. 45. Fig. 11.16
  40. 46. <ul><li>2. Anatomy of a synapse </li></ul><ul><ul><li>Pre-synaptic unit - end terminals of axon that comes before the synapse, has action potential invading the end terminal where synaptic vesicles are located </li></ul></ul><ul><ul><li>Synaptic vesicles contain neurotransmitters which will be released into the (chemical) synapse </li></ul></ul><ul><ul><li>Post-synaptic unit - dendrites or the cell body (possibly the axon) of the next neuron in the sequence, after the synapse, or could be an effectors </li></ul></ul>
  41. 47. Signal travels from pre-synaptic, across synapse, to post-synaptic unit
  42. 48. <ul><li>3. Neurotransmitter chemicals </li></ul><ul><ul><li>a) Synaptic vesicle of the pre-synaptic side are membrane bound vesicles that contain specific chemicals = neurotransmitters </li></ul></ul><ul><ul><li>b) There are dozens of different types of neurotransmitters </li></ul></ul><ul><ul><li>c) Norepinephrine (norepi/NE) </li></ul></ul><ul><ul><ul><li>Found in the CNS and the Autonomic NS </li></ul></ul></ul><ul><ul><ul><li>Stimulates different parts of the CNS </li></ul></ul></ul><ul><ul><ul><li>Can stimulate OR inhibit the ANS (see VI) </li></ul></ul></ul><ul><ul><ul><li>Often similar action to Epinephrine </li></ul></ul></ul>
  43. 49. <ul><li>3. Neurotransmitters (continued) </li></ul><ul><ul><li>d) Acetylcholine (Ach) </li></ul></ul><ul><ul><ul><li>Found in the CNS and the Peripheral NS </li></ul></ul></ul><ul><ul><ul><li>Stimulates in the Somatic NS - skeletal muscles </li></ul></ul></ul><ul><ul><ul><li>Can stimulate OR inhibit the ANS (see VI) - involuntary muscle and glands </li></ul></ul></ul><ul><ul><li>e) Serotonin </li></ul></ul><ul><ul><ul><li>Found only in the CNS </li></ul></ul></ul><ul><ul><ul><li>Inhibits a variety of neurons </li></ul></ul></ul><ul><ul><ul><li>Anti-depressants (Prozac) work on serotonin </li></ul></ul></ul><ul><ul><li>f) GABA - inhibitory in the CNS </li></ul></ul>
  44. 50. <ul><li>3. Neurotransmitters (continued) </li></ul><ul><ul><li>g) Dopamine </li></ul></ul><ul><ul><ul><li>Found primarily in the CNS </li></ul></ul></ul><ul><ul><ul><li>Can stimulate or inhibit different areas </li></ul></ul></ul><ul><ul><li>h) Nitric Oxide (NO) </li></ul></ul><ul><ul><ul><li>Gas molecule released as a local regulator peripherally </li></ul></ul></ul><ul><ul><ul><li>NO causes smooth muscle to relax </li></ul></ul></ul><ul><ul><ul><li>Work on blood vessels, smooth muscle of penis, etc. </li></ul></ul></ul>
  45. 51. A&P - Table 11.3
  46. 52. <ul><li>4. Actions at the synapse </li></ul><ul><ul><li>a) pre-synaptic unit fires / depolarizes / is active as an electrical charge is propagated down the axon (remember Na + /K + changes of part II) </li></ul></ul><ul><ul><li>b) the electrical signal invades the pre-synaptic area of the terminal branch and the electrical signal dies - Why might signal die in this area? </li></ul></ul><ul><ul><li>c) Calcium channels open and Ca ++ enters the pre-synaptic area from the extracellular environment </li></ul></ul><ul><ul><li>d) Ca ++ causes the synaptic vesicles to migrate towards the pre-synaptic membrane and fuse with the membrane = exocytosis </li></ul></ul><ul><ul><li>e) the vesicle contents - neurotransmitter - is released into the synaptic space and starts to diffuse across to the post-synaptic side </li></ul></ul>
  47. 53. Fig. 48-12 A&P Flix
  48. 55. <ul><li>4. Actions at synapse (continued) </li></ul><ul><ul><li>f) as chemical reaches post-synaptic membrane, it reacts with specific receptors on this side to trigger a response by the post-synaptic unit due to a change in post-synaptic membrane permeability </li></ul></ul><ul><ul><li>g) if the post-synaptic membrane is now more permeable to Na + by opening sodium channels, </li></ul></ul><ul><ul><ul><li>this neuron becomes excited and depolarizes </li></ul></ul></ul><ul><ul><li>h) if the post-synaptic membrane is now more permeable to K + or Cl - </li></ul></ul><ul><ul><ul><li>this neuron becomes inhibited and hyperpolarizes - WHY? </li></ul></ul></ul><ul><ul><li>A single post-synaptic neuron will have different types of receptors on its membrane - like a door with several locks - each receptor can be activated by a different chemical </li></ul></ul>
  49. 56. Fig. 48-14 or (11-19) EPSP = excitatory postsynaptic potential (depolarizing) IPSP = inhibitory postsynaptic potential (hyperpolarizing)
  50. 57. Fig. 11-6
  51. 58. <ul><li>5. Summary </li></ul><ul><ul><li>a) Excitation or Depolarization </li></ul></ul><ul><ul><ul><li>due to increase in positive charges intracellular which brings membrane potential towards threshold which allows sodium gates to open and neuron fires </li></ul></ul></ul><ul><ul><li>b) Inhibition or Hyperpolarization </li></ul></ul><ul><ul><ul><li>Due to an increase in negative charges intracellular or positive charges leaving (K + ) which brings the membrane potential away from threshold, making it HARDER to fire this neuron </li></ul></ul></ul><ul><ul><li>c) How do we turn off the neurotransmitter? </li></ul></ul>
  52. 59. <ul><li>5d) As long as neurotransmitter is present in the synapse, it will keep reacting with post-synaptic receptors and keep the gates/channels open or closed and the reaction continues. </li></ul><ul><ul><li>1. Norepinephrine and Epinephrine are transported AWAY from synapse or transported back into the pre-synaptic unit to be recycles </li></ul></ul><ul><ul><li>2. Acetylcholine has specific enzyme in the synapse - Acetylcholinesterase - which cleaves the Ach into Acetyl plus Choline to be recycled </li></ul></ul>
  53. 60. <ul><li>6. Summation and Integration </li></ul><ul><ul><li>Number of excitatory vs. inhibitory synaptic inputs determine post-synaptic response </li></ul></ul><ul><ul><li>Time course of inputs </li></ul></ul><ul><ul><li>Examples </li></ul></ul><ul><ul><ul><li>Car - brake and gas pedal </li></ul></ul></ul><ul><ul><ul><li>Preying Mantis </li></ul></ul></ul>
  54. 61. <ul><li>7. Effect of Drugs on Synaptic Activity </li></ul><ul><ul><li>a) Insecticide or nerve gas </li></ul></ul><ul><ul><ul><li>What is behavior of animal exposed to this poison? </li></ul></ul></ul><ul><ul><ul><li>Block the action the enzyme which destroys Ach </li></ul></ul></ul><ul><ul><ul><li>Acetylcholinesterase = rigidity of muscles </li></ul></ul></ul><ul><ul><li>b) Curare </li></ul></ul><ul><ul><ul><li>Derived from plants </li></ul></ul></ul><ul><ul><ul><li>Blocks receptors on skeletal muscle </li></ul></ul></ul><ul><ul><ul><li>Prevents Ach from working - muscle flaccid/relaxed </li></ul></ul></ul><ul><ul><li>c) Stimulants / Amphetamines </li></ul></ul><ul><ul><ul><li>Mimic action of Norepi in brain </li></ul></ul></ul><ul><ul><ul><li>Stimulate release of Norepi in brain </li></ul></ul></ul><ul><ul><ul><li>Dependency </li></ul></ul></ul><ul><ul><ul><li>What over counter pill a stimulant, but not used to keep you awake? </li></ul></ul></ul>
  55. 62. <ul><li>7. Drugs (continued) </li></ul><ul><ul><li>d) Depressants / Anesthetics </li></ul></ul><ul><ul><ul><li>Inhibit many centers in the brain </li></ul></ul></ul><ul><ul><ul><li>Base of brain and higher up </li></ul></ul></ul><ul><ul><ul><li>Overdose = depresses respiratory centers </li></ul></ul></ul><ul><ul><ul><li>Alcohol? </li></ul></ul></ul><ul><ul><li>e) LSD / Hallucinogenic Drugs </li></ul></ul><ul><ul><ul><li>Normally - there is inhibition between the different sensory inputs </li></ul></ul></ul><ul><ul><ul><li>Smell goes to one place, sight another region </li></ul></ul></ul><ul><ul><ul><li>These drugs cause overspill of one input to different areas of the brain, so you see a sound, taste a light </li></ul></ul></ul><ul><ul><ul><li>Yellow Submarine experiment </li></ul></ul></ul>
  56. 64. IV. Spinal cord A. Definitions <ul><li>1. Grey Matter - collection of neuron cell bodies and dendrites within the CNS </li></ul><ul><li>2. White Matter - collection of myleinated axons within the CNS </li></ul><ul><li>3. Nucleus - a cluster or collection of related neurons within the CNS </li></ul><ul><li>4. Ganglion - a collection of related neuron cell bodies outside the CNS, in the periphery </li></ul><ul><li>5. Interneuron or Association neuron - connecting neuron within the CNS </li></ul>
  57. 65. Fig. 12.31/33
  58. 66. <ul><li>6. Ascending tracts - related sensory axons within the white matter of the CNS </li></ul><ul><li>7. Descending tracts - related motor axons within the white matter of the CNS </li></ul><ul><li>8. Meninges - three membranes that cover the entire CNS (brain and spinal cord) </li></ul><ul><ul><li>Dura Mata - tough , fibrous outer membrane that protects </li></ul></ul><ul><ul><li>Arachnoid membrane - middle layer that supports the blood vessels in a sub-arachnoid space (web like appearance) </li></ul></ul><ul><ul><li>Pia Mata - inner most membrane, (gentle) tissue paper thin but helps shape CNS, which normally has a jell-like consistency </li></ul></ul>
  59. 67. Fig. 12.24
  60. 68. <ul><li>9. Cerebral Spinal Fluid - CSF </li></ul><ul><ul><li>a) Formed in ventricles of brain as a filtrate of blood, CSF circulates through ventricles and central canal </li></ul></ul><ul><ul><ul><li>Stabilize extracellular environment </li></ul></ul></ul><ul><ul><ul><li>Tight junctions between capillary cells plus glial cells </li></ul></ul></ul><ul><ul><ul><li>Selective, not absolute permeability - varies in different parts of the brain (hypothalamus, vomit center) </li></ul></ul></ul><ul><ul><li>b) Ventricles - fluid-filled spaces of brain (large lateral, 3rd, 4th ventricles) </li></ul></ul><ul><ul><li>c) CSF carries nutrients, hormones, white blood cells and acts as shock absorber </li></ul></ul><ul><ul><li>d) After circulating in the CNS, CSF returns to veins on the surface of the brain, carrying wastes </li></ul></ul>
  61. 69. Fig. 12.26
  62. 70. Fig. 12.26b
  63. 71. <ul><li>9. CSF (continued) </li></ul><ul><ul><li>e) Meningitis - inflammation of the meninges, bacterial or viral, can spread to the nervous tissue of the CNS </li></ul></ul><ul><ul><li>f) Encephalitis - brain inflammation </li></ul></ul><ul><ul><li>g) Hydrocephalus - water on the brain - CSF forms normally, but there is an obstruction to flow and it accumulates in ventricles </li></ul></ul><ul><ul><ul><li>New born - enlarged head since skull bones not fused </li></ul></ul></ul><ul><ul><ul><li>Adult - compresses blood vessels and crushes soft nervous tissue </li></ul></ul></ul><ul><ul><ul><li>Remove obstruction or insert shunt to drain CSF </li></ul></ul></ul>
  64. 72. <ul><li>10. Spinal Puncture </li></ul><ul><ul><li>Removal of CSF below L 1 where spinal cord has ended </li></ul></ul><ul><ul><li>Nerves exiting at this point drift away from needle </li></ul></ul><ul><ul><li>Fluid removed from subarachnoid space and analyzed </li></ul></ul><ul><ul><li>Look for infection, excessive white blood cells, proteins, removal of hydrostatic pressure on the CNS </li></ul></ul>
  65. 73. IV. B. Spinal cord anatomy <ul><li>1. Spinal cord runs from base of brain to L 1 segment with enlargements in cervical and lumbar areas for serving arms and legs and 31 pairs of mixed spinal nerves </li></ul><ul><li>2. Dermatome - area of skin that has sensory innervations from a specific spinal nerve, there is some overlap </li></ul><ul><li>3. Spinal cord cross-section: Identify </li></ul><ul><ul><li>Deeper anterior/ventral median fissure </li></ul></ul><ul><ul><li>Shallow posterior/dorsal median sulcus </li></ul></ul><ul><ul><li>Central canal in middle of grey matter </li></ul></ul><ul><ul><li>Surrounding white matter </li></ul></ul><ul><ul><li>Dorsal and ventral horns connecting to a spinal nerve </li></ul></ul>
  66. 74. Fig. 48-16
  67. 75. Fig. 13.12
  68. 76. IV. B. Spinal Cord anatomy (continued) <ul><li>4. Trace the following pathway: (use diagram in notes) </li></ul><ul><ul><li>Sensory receptor or dendrites (stimulus) </li></ul></ul><ul><ul><li>Myelinated dendrite passes through spinal nerve </li></ul></ul><ul><ul><li>Travels up dorsal root </li></ul></ul><ul><ul><li>Dendrite finds its own sensory cell body in dorsal root ganglion </li></ul></ul><ul><ul><li>Central process/axon exits ganglion and travels in dorsal root to spinal cord </li></ul></ul><ul><ul><li>Enters dorsal horn proper of grey matter and synapses with an interneuron </li></ul></ul><ul><ul><li>Interneuron sends branch to brain AND branch to ventral area of grey matter and </li></ul></ul><ul><ul><li>Synapses with motor cell body in ventral horn </li></ul></ul><ul><ul><li>Motor axon exits spinal cord via ventral root and enters same spinal nerve (mixed) </li></ul></ul><ul><ul><li>Motor axon innervates an effector and a response occurs </li></ul></ul>
  69. 77. <ul><li>5. There are synapses - </li></ul><ul><ul><li>One between incoming sensory axon and dendrite/cell body of interneuron </li></ul></ul><ul><ul><li>Second between the terminal branch of the interneuron and the dendrite/cell body of the motor neuron </li></ul></ul><ul><ul><li>Third between the motor terminal branch and the effector (neuromuscular junction) </li></ul></ul><ul><ul><li>Why is there not a synapse in the dorsal root ganglion? </li></ul></ul><ul><li>6. Injections: </li></ul><ul><ul><li>Epidural - outside the dura mater and outside the spinal cord (more sensory in effect) </li></ul></ul><ul><ul><li>Subdural - into the CSF area of the middle arachnoid membrane and penetrates the spinal cord (both sensory and motor in its effects) </li></ul></ul>
  70. 78. IV. C. Spinal Cord Reflexes <ul><li>1. Reflex - innate, automatic response to a given stimulus </li></ul><ul><li>2. Reflex arc - functional unit of the stimulus-response mechanism, highly specific neural pathway involving above (B.4.) </li></ul><ul><li>3. Two types of reflexes </li></ul><ul><ul><li>Inborn / inherited </li></ul></ul><ul><ul><li>Learned / acquired / conditioned </li></ul></ul>
  71. 80. Fig. 48-3& A&P Flix
  72. 81. Fig.13.18
  73. 82. <ul><li>4. Inborn or inherited or 2 neuron reflex </li></ul><ul><ul><li>Pupillary eye reflex to light, heart rate </li></ul></ul><ul><ul><li>Patellar knee reflex, respiration </li></ul></ul><ul><ul><li>2 neuron reflex - sensory synapses directly with motor output, monosynaptic </li></ul></ul><ul><ul><li>No interneuron - no involvement of brain </li></ul></ul><ul><ul><li>No conscious control over response </li></ul></ul><ul><li>5. Learned or conditioned or polysynaptic or 3 neuron reflex </li></ul><ul><ul><li>Finger on hot stove </li></ul></ul><ul><ul><li>3 neurons - sensory, interneuron, motor, multisynaptic </li></ul></ul><ul><ul><li>Interneuron involves the brain which adds a conscious control over the motor response </li></ul></ul><ul><ul><li>Can you leave your finger on a hot stove for 30 seconds? </li></ul></ul>
  74. 83. <ul><li>6. Crossed Reflex </li></ul><ul><ul><li>Interneuron crosses to opposite side of the spinal cord as well </li></ul></ul><ul><ul><li>Reflex excites extensor on one side and flexor on the other side </li></ul></ul><ul><ul><li>Think of balancing on see-saw or stepping on a sharp tack </li></ul></ul>Fig. 13.19
  75. 84. Figs. 12.1/2 V. BRAIN
  76. 85. V. Brain <ul><li>A. Cerebrum or Cerebral Hemispheres </li></ul><ul><ul><li>1. Mammals - grows over other, older parts of the brain, assumed functions or control over older portions </li></ul></ul><ul><ul><ul><li>Furrows and convolutions of surface to increase surface area of gray matter </li></ul></ul></ul><ul><ul><ul><li>White matter of cortex = ascending and descending tracts plus interneurons within cortex </li></ul></ul></ul><ul><ul><ul><li>Left - Right Hemispheres connected via the Corpus Callosum - band of connecting interneuron axons </li></ul></ul></ul><ul><ul><ul><li>Ventricles and CSF </li></ul></ul></ul><ul><ul><ul><li>Function of the left brain?? Anatomical control?? </li></ul></ul></ul><ul><ul><ul><li>Function of the right brain?? Anatomical control?? </li></ul></ul></ul><ul><ul><ul><li>Lobes = frontal, parietal, occipital, temporal </li></ul></ul></ul>
  77. 86. Fig. 12.5
  78. 87. Fig. 12.4
  79. 88. Fig. 12.10
  80. 89. <ul><li>Figs. 12.6 </li></ul>
  81. 90. Fig. 48-24
  82. 91. Fig. 28-25 or 12.9
  83. 92. <ul><li>A. Cerebrum (continued) </li></ul><ul><ul><li>2. Function and locations </li></ul></ul><ul><ul><ul><li>Controls learned behavior </li></ul></ul></ul><ul><ul><ul><li>Highest reflection of sensory input (parietal) </li></ul></ul></ul><ul><ul><ul><ul><li>Vision - occipital </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Hearing - temporal </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Olfaction - temporal </li></ul></ul></ul></ul><ul><ul><ul><li>Highest origin of motor output (frontal) </li></ul></ul></ul><ul><ul><ul><li>Integrative functions for both </li></ul></ul></ul><ul><ul><ul><li>Intelligence </li></ul></ul></ul><ul><ul><ul><li>Memory </li></ul></ul></ul><ul><ul><ul><li>Language and speech (frontal & temporal) </li></ul></ul></ul><ul><ul><ul><li>Emotions (see limbic system) </li></ul></ul></ul>
  84. 93. Fig. 12.8
  85. 94. Fig. 12.8
  86. 95. Fig. 28-20
  87. 96. Fig. 28-27 or 12.18
  88. 97. <ul><li>A. Cerebrum (continued) </li></ul><ul><ul><li>3. Cut corpus callosum = split brain </li></ul></ul><ul><ul><li>4. Limbic System </li></ul></ul><ul><ul><ul><li>Emotion due to interactions with sensory input and association centers </li></ul></ul></ul><ul><ul><ul><li>Memory - Hippocampus </li></ul></ul></ul><ul><ul><ul><li>Frontal lobotomy </li></ul></ul></ul><ul><ul><li>5. Basal Ganglia </li></ul></ul><ul><ul><ul><li>Conscious and unconscious movements </li></ul></ul></ul><ul><ul><ul><li>Movement sequencing </li></ul></ul></ul><ul><ul><ul><li>Parkinson’s and Huntington’s diseases </li></ul></ul></ul><ul><ul><ul><li>Dopamine involvement ( Awakenings ) </li></ul></ul></ul>
  89. 98. Fig. 12.11b Basal Ganglia
  90. 99. Fig. 12.17
  91. 100. <ul><li>B. Cerebellum </li></ul><ul><ul><li>1. Under cortex, above medulla </li></ul></ul><ul><ul><li>2. Convoluted surface with internal axons </li></ul></ul><ul><ul><li>3. Communicates with many other areas (F 4 .) </li></ul></ul><ul><ul><ul><li>Sensory and motor areas </li></ul></ul></ul><ul><ul><li>4. Monitors and corrects motor activities </li></ul></ul><ul><ul><ul><li>Posture </li></ul></ul></ul><ul><ul><ul><li>Muscle coordination </li></ul></ul></ul><ul><ul><ul><li>Error control compares intention with performance </li></ul></ul></ul>
  92. 101. Fig. 12.12
  93. 102. Fig. 12.13
  94. 103. <ul><li>C. Thalamus </li></ul><ul><ul><li>1. Collection of nuclei bordering the third ventricle </li></ul></ul><ul><ul><li>2. Communicates with other areas (see F 4 below) </li></ul></ul><ul><ul><li>3. Relay for sensory input to the cerebrum </li></ul></ul><ul><ul><li>4. Conscious recognition </li></ul></ul><ul><li>D. Hypothalamus </li></ul><ul><ul><li>1. Below the thalamus, above the pituitary gland </li></ul></ul><ul><ul><li>2. Communicates with other areas (see F 4 below) </li></ul></ul><ul><ul><li>3. Psychosomatic disorders ?? </li></ul></ul><ul><ul><ul><li>Endocrine functions - produces different hormones that control the pituitary and other body organs and functions </li></ul></ul></ul><ul><ul><li>4. Nuclei controlling Autonomic Functions </li></ul></ul><ul><ul><ul><li>Food intake Fluid balance </li></ul></ul></ul><ul><ul><ul><li>Temperature regulation Sex Drive </li></ul></ul></ul><ul><ul><ul><li>Pleasure - Pain </li></ul></ul></ul>
  95. 104. <ul><li>E. Pons </li></ul><ul><ul><li>1. Posterior to the hypothalamus, part of the Brain Stem </li></ul></ul><ul><ul><li>2. Communicates with other areas (F.) </li></ul></ul><ul><ul><li>3. Influences other breathing centers of brain </li></ul></ul><ul><li>F. Medulla (oblongata) </li></ul><ul><ul><li>1. Part of the Brain Stem, connects the brain to the spinal cord </li></ul></ul><ul><ul><li>2. Conduction pathway for incoming sensory axons and outgoing motor axons </li></ul></ul><ul><ul><li>3. Nuclei that control Vital Reflexes </li></ul></ul><ul><ul><ul><li>Cardiac Respiratory centers </li></ul></ul></ul><ul><ul><ul><li>Swallow Cough Vomit centers </li></ul></ul></ul><ul><ul><li>4. Origin of the Reticular formation </li></ul></ul>
  96. 105. Fig. 12.16a/b
  97. 106. Fig. 12.16c
  98. 107. Fig. 28-21 or 12.19
  99. 108. F. Medulla 4. Reticular formation (continued) <ul><ul><li>Ability to facilitate or inhibit incoming sensory and outgoing motor activities </li></ul></ul><ul><ul><ul><li>Aids in ignoring certain stimuli as brain processes other inputs </li></ul></ul></ul><ul><ul><li>Responsible for normal arousal of the higher centers of brain </li></ul></ul><ul><ul><li>Patient in coma </li></ul></ul><ul><ul><li>Muscle jerk as one falls asleep </li></ul></ul><ul><ul><ul><li>Response??? </li></ul></ul></ul><ul><li>G. EEG or Brain Waves </li></ul><ul><ul><li>External detection of depolarizations and hyperpolarizations over brain </li></ul></ul><ul><ul><li>Alpha = quiet rest Beta = active </li></ul></ul><ul><ul><li>Theta = stress Delta = sleep </li></ul></ul>
  100. 109. Fig. 48-22 Fig. 12.20
  101. 110. Fig. 13.5
  102. 111. <ul><li>H. Cranial Nerves </li></ul><ul><ul><li>1. 12 pairs exiting/entering from the brainstem </li></ul></ul><ul><ul><li>2. Olfactory (#1) - sensory </li></ul></ul><ul><ul><li>3. Optic (#2) - sensory to optic chiasm </li></ul></ul><ul><ul><li>4. Trigeminal (#5) - mixed - chewing and facial sensations </li></ul></ul><ul><ul><li>5. Vagus (#10) - mixed from.to all over body including cardiac, visceral and skeletal </li></ul></ul><ul><li>I. Neural Disorders </li></ul><ul><ul><li>1. Polio - viral degeneration of ventral horn motor cell bodies of spinal cord </li></ul></ul><ul><ul><li>2. Cerebral palsy - voluntary muscles are poorly controlled due to brain damage during fetal development or birth (oxygen deprivation) </li></ul></ul>
  103. 112. <ul><li>I. Disorders (continued) </li></ul><ul><ul><li>3. Parkinson’s Disease - degeneration of dopamine producing cells of the substantia nigra, which target Basal Ganglia cells of the inner cerebrum </li></ul></ul><ul><ul><ul><li>Tremors </li></ul></ul></ul><ul><ul><ul><li>Slow in initiating and executing voluntary motion </li></ul></ul></ul><ul><ul><ul><li>L-dopa compounds, fetal tissue, genetically engineered adult cells </li></ul></ul></ul><ul><ul><li>4. Multiple Sclerosis - autoimmune loss of myelin from motor and sensory neurons causes short-circuiting of signals </li></ul></ul><ul><ul><ul><li>Since axon healthy, variable remissions occur </li></ul></ul></ul>
  104. 113. <ul><li>5. Alzheimer’s Disease - progressive degeneration of the brain resulting in dementia (genetic factors) </li></ul><ul><ul><li>Ach problems </li></ul></ul><ul><ul><li>Structural changes in cerebrum and hippocampus </li></ul></ul><ul><ul><li>Protein bound to beta amyloid protein plus neurofibrillar tangles in cell body </li></ul></ul><ul><li>6. Stroke or CVA - blockage of blood circulation to brain and brain tissue dies </li></ul><ul><ul><li>Caused by clot, compression by hemorrhaging or edema </li></ul></ul><ul><ul><li>Atherosclerosis - narrowing of blood vessel by deposits </li></ul></ul>
  105. 114. VI. Autonomic Nervous System <ul><li>1. Peripheral Nervous system </li></ul><ul><ul><li>Somatic NS - </li></ul></ul><ul><ul><li>Autonomic NS - involuntary motor system that connects to cardiac and smooth muscles and glands </li></ul></ul><ul><li>2. Two divisions of the ANS </li></ul><ul><ul><li>Parasympathetic NS </li></ul></ul><ul><ul><li>Sympathetic NS </li></ul></ul><ul><li>3. Dual Innervations - both parasympathetic and sympathetic systems connect to the same effectors </li></ul><ul><ul><li>Heart Intestine Salivary glands etc. </li></ul></ul><ul><ul><li>Why have two systems to same organs? </li></ul></ul>
  106. 115. Fig. 14.2
  107. 116. Fig. 14.3
  108. 117. <ul><li>4. Antagonist Functions of the 2 ANS divisions </li></ul><ul><ul><li>One system excites and the other system inhibits </li></ul></ul><ul><li>Organ Parasympathetic Sympathetic </li></ul><ul><li>Heart </li></ul><ul><li>Smooth </li></ul><ul><li>muscle </li></ul><ul><li>Of </li></ul><ul><li>Digestive </li></ul><ul><li>System </li></ul>
  109. 118. Organ Parasympathetic Sympathetic Inhibits Heart Rate & Strength of beat Heart (cardiac muscle) Increases HR & Strength of beat Stimulates Peristalsis - smooth rhythmic contraction of gut Smooth Muscle of Digestive System Inhibits Peristalsis
  110. 119. <ul><li>5. Properties of Parasympathetic NS </li></ul><ul><ul><li>a) 80% of all parasympathetic activity from brain is associated with the Vagus Nerve (10th cranial nerve), all parasympathetic nerves originate from the top or bottom of the spinal cord </li></ul></ul><ul><ul><li>b) main neurotransmitter released is Acetylcholine </li></ul></ul><ul><ul><li>c) main functions: conserve or restore energy levels in the body </li></ul></ul><ul><ul><ul><li>Appetite related </li></ul></ul></ul><ul><ul><ul><li>Digestion </li></ul></ul></ul><ul><ul><ul><li>excretion </li></ul></ul></ul>
  111. 120. Figs. 14.4/6
  112. 121. <ul><li>6. Properties of Sympathetic NS </li></ul><ul><ul><li>a) no one single nerve, but nerves originate from the middle of the spinal cord </li></ul></ul><ul><ul><li>b) main neurotransmitter released is Norepinephrine plus these nerves also release hormones of the adrenal gland to prolong the actions of the sympathetics </li></ul></ul><ul><ul><li>c) main function: utilize energy </li></ul></ul><ul><ul><ul><li>Fight or Flight Syndrome </li></ul></ul></ul><ul><ul><ul><li>Stress Related - opposite of homeostasis </li></ul></ul></ul><ul><ul><li>d) too much stress causes imbalance between these two systems resulting in changes in blood pressure, ulcers, heart arrhythmias, etc. </li></ul></ul><ul><ul><li>e) reduce stress in your life - don’t let Biology get to you! </li></ul></ul>
  113. 122. Fig. 14.9 Levels of ANS Control