BSCI201 FINAL EXAM REVIEWTHE NERVOUS SYTEM: CNS + PNS1. Nissl body: well-developed rough ER in cell body of neuron2. Neurofilaments: intermediate filaments in neuron3. Ganglia:4. Nuclei: 5. Tract: bundle of axons in CNS6. Nerve: bundle of axons in PNS7. Axonal terminals: bulbous ends at end of axon8. Neurilemma: cytoplasm and nucleus of Schwann cell squeezed outside myelin sheath9. Nodes of Ranvier: spaces between adjacent myelin sheaths 10. Endoneurium: delicate CT wrapped around each axon11. Perineurium: coarse CT wrapped around each fascicle12. Epineurium: tough CT wrapped around a nerve/tract13. Cell body = biosynthetic region of neuron 14. Dendrites = receptive region of neuronSUPPORTING CELLS (Neuroglia)LOCATED IN CNS:15.Astrocytes: form blood-brain barrier (regulates chemical environment of brain)a. Regulates brain function16.Microglia: macrophages that engulf/destroy pathogens and cell debris17.Ependymal cells: ciliated columnar cells that line ventricles (cavities in brain that contain cerebrospinal fluid)18.Oligodendrocytes: extensions myelinate axons of neurons in CNSLOCATED IN PNS:19.Schwann cells: myelinate axons of neurons in PNS20.Satellite cells: surround cell bodies of neurons + control chemical environment21.Myelinated axons in CNS do not regenerate when severed b/c:a. Microglia poorly clean up area of damageb. No neurilemma to guide growth of severed axonc. Growth-inhibiting proteins in CNS inhibit regeneration of severed axon22.Impulses conducted faster in larger myelinated axon that in smaller unmyelinated axon b/c larger axon = larger diameter less resistance impulse transmission a. Myelinated axons transmit impulses faster than unmyelinated23.DEPOLARIZATION PHASE of action potential:a. Entry of sodium ions membrane potential less negativeb. Spike b/c of entry of sodium ions = positive membrane potential reached24. REPOLARIZATION PHASE of action potential:a. Sodium channels close b. Potassium channels open + potassium ions rush outc. Reversal of membrane potential toward negative membrane potential25. ABSOLUTE REFRACTORY PERIOD: depolarization phase of action potential when sodium channels are openeda. Another action potential cannot be generated26. RELATIVE REFRACTORY PERIOD: repolarization phase of action potential when sodium channels close/potassium channels opena. Strong stimulus can cause sodium channels to open sodium ion influx depolarization generation of another action potentialSTRUCTURAL CLASSES OF NEURONS27. Multipolar: at least 3 processes – 1 axon and at least 2 dendrites; most abundant neuron in human body28. Bipolar: 2 processes – 1 axon and 1 dendrite29. Pseudounipolar: 1 short process from cell body + bifurcates into central process + peripheral process FUNCTIONAL CLASSES OF NEURONS30. Motor/Efferent: transmits impulses AWAY FROM CNS to effector organs 31. Sensory/Afferent: transmits impulses from sensory receptors TOWARD CNS32. Association neurons/interneurons: located in CNS b/w sensory neurons and motor neurons a. Most of neurons in body are association neurons 3 TYPES OF NERVE FIBERS33. Group A fibers: largest diameter + heavily myelinateda. Fastest conduction velocity34. Group B fibers: intermediate diameter + lightly myelinated35. Group C fibers: smallest diameters + unmyelinatedTHE BRAIN 4 PROTECTIVE STRUCTURES:36. Cranium: bony helmet of 8 cranial bones – frontal, parietal, temporal, occipital, sphenoid, ethmoid37. Meninges: 3 connective membranes surrounding braina. DURA MATER : outermost; double-layered (outer periosteal, inner meningeal)b. ARACHNOID MATER : middlec. PIA MATER : innermost; clings to surface of brain 38. Cerebrospinal fluid (CSF): filtered from blood; inside and outside of brain. Functions:a. Liquid cushionb. Buoyancy to brainc. Provides nutrientsd. Removes metabolic wastes39. Blood-brain barrier: prevents harmful substances in blood from crossing tobrainDEFINITIONS40. Septum pellucidum: median membrane that connects 2 lateral ventricles41. Interventricular foramen: channel that connects 2 lateral ventricles to 3rd ventricle42. Cerebral aqueduct: connects 3rd ventricle to 4th ventricle43. LATERAL VENTRICLES: in each cerebral hemisphere44. 3rd VENTRICLE: in diencephalon45. 4th VENTRICLE: in brain stem4 REGIONS OF ADULT BRAIN46. CEREBRUM47. DIENCEPHALON48. BRAINSTEM49. CEREBELLUMCEREBRUM50. Gyrus: elevated ridge on surface of cerebrum51. Sulcus: shallow grooves on surface of cerebrum52. Fissure: deeper grooves53. Corpus callosum: holds together 2 cerebral hemispheres54. Gray matter: cell bodies, dendrites; makes up cerebral cortex55. White matter: deep to cerebral cortex; tracts with myelinated axons 3 TRACTS IN CEREBRAL WHITE MATTER:56. Commissural tracts: connect corresponding areas in 2 cerebral hemispheresa. Ex. Corpus callosum57. Projection tracts: connect cerebrum to lower brain areas + spinal corda. Ex. Pyramidal tracts58. Association tracts: connect areas within same cerebral hemispherea. Ex. Arcuate fasciculate 5 LOBES IN CEREBRAL HEMISPHERE59. Frontal lobe60. Temporal lobe61. Parietal lobe62. Occipital lobe63. Insula – cannot be viewed externally; deep to lateral sulcus3 FUNCTIONAL AREAS IN CEREBRAL CORTEX:64. MOTOR AREAS: voluntary movementsa. Primary motor cortex, premotor cortex, Broca’s area, frontal eye fieldb. All located in frontal lobes65. SENSORY AREAS: conscious awareness of sensationa. Primary somatosensory cortex, primary visual cortex, primary auditory cortex, primary olfactory cortex, primary gustatory cortex66. ASSOCIATION AREAS: integrate/interpret sensory inputs from sensory areas3 MAJOR BASAL NUCLEI (islands of gray matter in cerebral white matter)67. Caudate nucleus68. Putamen69. Globus pallidus a. LENTIFORM NUCLEUS = putamen + globus pallidusb. CORPUS STRIATUM = lentiform nucleus + caudate 70. PARKINSON’S DISEASE: caused by degeneration of dopaminergic neurons to basal nuclei SPINAL CORD71. Conus medullaris: papery cone-shaped structure that ends spinal cord72. Cauda equina: whip-like structure formed from spinal nerves exiting form area below where spinal cord ends 73. Filum terminale: fibrous extension from spinal cord that anchors spinal cord vertically to coccyx74. Epidural space: filled with fat and veins 75. Subdural space: arachnoid mater separated from spinal dural sheath76. Subarachnoid space: separates arachnoid mater from pia matera. Contains CSF77. Central canal: core of spinal cord; contains CSF from 4th ventricle in brain stem78.
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