Central Nervous System Overview

1. Nervous System: Consists of all the nerve cells. 2. Central Nervous System Brain and spinal cord responsible for voluntary (CNS) and involuntary actions. 3. Peripheral Nervous Sys- the sensory and motor neurons that connect the tem (PNS): central nervous system (CNS) to the rest of the body. 4. three major parts of the brain forebrain midbrain and hindbrain 5. Forebrain deals with thought and planning, memory, sensory processing, and emotion regulation. 6. Midbrain relaying sensory info, coordinating movement, and maintaining alertness. 7. Hindbrain Brain region regulating vital functions, balance, coordination, and reflexes. 8. Grey Matter Brain tissue with cell bodies; extends to spinal cord for signaling. 9. what cell bodies does the motor and sensory neurons, interneurons, and grey matter consist of neuropils 10. what is grey matter also substantia grisea known as 11. White Matter function facilitates communication. 12. what is white matter com- interconnecting fiber tracts, myelinated sensory posed of and motor axons. 13. what is white matter also substantia alba, known as 14. Cerebral Cortex Outer brain layer divided into 6 lobes for cognitive functions. 1/6 15. 6 lobes of the cerebral cortex frontal, temporal, parietal, occipital, insular and limbic lobes. 16. three primary roles of the send motor commands from the brain to the body spinal cord send sensory information from the body to the brain, and coordinate reflexes 17. Meninges Three protective layers covering the brain and spinal cord. 18. what is cerebrospinal flu- form of protection, a buffer that limits impact beid tween the brain and skull or between spinal cord and vertebrae. 19. Meningitis Infection of brain and spinal cord protective membranes. 20. how is meningitis tested cerebrospinal fluid analysis and culture or by for necropsy. 21. causes of meningitis Epsilon-toxin (ETX) Cocaine and methamphetamine heavy metals like lead and mercury, carbon monoxide and pesticides, 22. Cranial Nerves 12 nerves connected to the brain 23. function of cranial nerves • Seeing, smelling, tasting, hearing, and feeling things • Moving your face muscles for expressions • Blinking and moving your tongue 24. Spinal Nerves 31 pairs of nerves from the spinal cord connecting it to the rest of the body 25. what are spinal nerves functions • Sending signals from your body to your brain (touch, pain, etc.) 2/6 • Carrying messages from your brain to control your muscles 26. Nerve Bundle of neurons, connective tissue, blood vessels, and lymphatics. 27. Neuron Cell conducting nerve impulses in the nervous system. 28. fundamental units of the neurons (nerve cells / nerve fibres) nervous system 29. Sympathetic Nervous System Mobilizes body for emergencies, fight-or-flight response. 30. Parasympathetic Nervous System Conserves bodily resources, slows heart rate, calms. 31. Action Potential Transmission of electrical signal along neurons. 32. Dendrites Neuron part responding to stimuli like neurotransmitters. 33. Axon Neuron part conducting action potentials away from the cell body. 34. sensory nerves report information from body to the brain 35. motor nerves sending messages from the central nervous system (brain and spinal cord) to the body for movement. 36. Synapses Points of contact between neurons for information transfer. 37. what does a synapses consist of presynaptic neuron, synaptic cleft, and a postsynaptic cell . 38. Glial Cells form myelin sheath around axons 3/6 39. Myelination Insulation of axons by glial cells, increasing conduction velocity. 40. Neurotransmitters Chemicals transmitting signals between neurons at synapses. 41. Excitatory Neurotransmitters Neurotransmitters that excite neurons to continue passing messages. 42. Inhibitory Neurotransmit- Neurotransmitters blocking further transmission ters of chemical messages. 43. Modulatory Neurotrans- Neurotransmitters adjusting how cells communimitters cate at synapses. 44. Reuptake Process where neurotransmitters are reabsorbed and reused by the releasing nerve cell. 45. Degradation Process where enzymes break down neurotransmitters within the synapse. 46. Neurotransmitter Synthe- Local synthesis in nerve terminals to replenish sis small synaptic vesicles. 47. Neuropeptide Synthesis Occurs in the cell soma, stored in vesicles until release 48. where does neurotrans- pre-synaptic neuron. mitter synthesis take place 49. Neurotoxicity Adverse change in nervous system due to chemical or physical exposure. 50. Reactive Oxygen Species (ROS) Initiators of peroxidative cell damage. 51. examples of Reactive Oxygen Species (ROS) superoxide anion, hydrogen peroxide, and hydroxyl radicals 4/6 52. Antioxidants Molecules stabilizing free radicals by donating electrons. causing free radical to stabilize and become less reactive 53. Oxidative Stress Imbalance between pro- and antioxidants causing cellular damage. 54. Neuronopathy Injury or death to neurons, irreversible loss. 55. Neuronopathy Types Includes sensory (ganglionopathy), motor, and autonomic neuronopathy. 56. Methylmercury Binds to cysteine, potent neurotoxin that can pass bbb and placental barrier 57. how does mercury persist in the environment by cycling back and forth between the air, water and soil, all the while changing chemical forms. 58. Bioaccumulation Chemical concentration increase in an organism over its life. 59. Biomagnification Chemical concentration increase in a food web. 60. how is methylmercury absorbed by fish by the tissues of fish through their gills as they swim, and also through their digestive tracts as they feed. 61. Minamata Disease Methylmercury poisoning from fish consumption. 62. cyanide odor "bitter almond" smell, but it does not always give off an odor 63. plant substance that when it is processed by the body, it changes to cyanide. Amygdalin found in raw nuts bitter almonds, as well as apricot and cherry seeds 64. Axonopathy Defects in axon structure or function. 65. 5/6 Axonopathy in cns vs pns 66. Cytoskeleton • Irreversible in CNS • Reversible in PNS Structure supporting cell shape and function. 67. Neurofilament prolifera- Hexa-carbons cause the breaking of axons tion: 68. Delayed Neuropathy Effects of Tri-o-cresyl phosphate TOCP appearing after 2-3 weeks. 69. Myelinopathy Polyneuropathy from myelin loss. 70. specialized glial cells for oligodendrocytes (CNS) cns and pns Schwann Cells (PNS) 71. V-Series Nerve Agents Highly potent acetylcholinesterase inhibitors. 72. • Biological effects of v series agents include seizures, salivation, lacrimation, urination, diaphoresis, diarrhea, vomiting, miosis, and muscles spasms 73. Sarin Potent nerve agent inhibiting acetylcholinesterase irriversibly. (g series nerve agent ) 74. Atropine Muscarinic receptor antagonist used in sarin nerve agent exposure treatment. 6/6