BSCI201 FINAL EXAM REVIEW THE NERVOUS SYTEM CNS PNS 1 Nissl body well developed rough ER in cell body of neuron 2 Neurofilaments intermediate filaments in neuron 3 Ganglia 4 Nuclei 5 Tract bundle of axons in CNS 6 Nerve bundle of axons in PNS 7 Axonal terminals bulbous ends at end of axon 8 Neurilemma cytoplasm and nucleus of Schwann cell squeezed outside myelin sheath 9 Nodes of Ranvier spaces between adjacent myelin sheaths 10 Endoneurium delicate CT wrapped around each axon 11 Perineurium coarse CT wrapped around each fascicle 12 Epineurium tough CT wrapped around a nerve tract 13 Cell body biosynthetic region of neuron 14 Dendrites receptive region of neuron SUPPORTING CELLS Neuroglia LOCATED IN CNS brain a Regulates brain function 15 Astrocytes form blood brain barrier regulates chemical environment of 16 Microglia macrophages that engulf destroy pathogens and cell debris 17 Ependymal cells ciliated columnar cells that line ventricles cavities in brain that contain cerebrospinal fluid 18 Oligodendrocytes extensions myelinate axons of neurons in CNS LOCATED IN PNS environment 19 Schwann cells myelinate axons of neurons in PNS 20 Satellite cells surround cell bodies of neurons control chemical 21 Myelinated axons in CNS do not regenerate when severed b c a Microglia poorly clean up area of damage b No neurilemma to guide growth of severed axon c Growth inhibiting proteins in CNS inhibit regeneration of severed 22 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 unmyelinated 23 DEPOLARIZATION PHASE of action potential a Entry of sodium ions membrane potential less negative b Spike b c of entry of sodium ions positive membrane potential axon reached 24 REPOLARIZATION PHASE of action potential a Sodium channels close b Potassium channels open potassium ions rush out c Reversal of membrane potential toward negative membrane potential 25 ABSOLUTE REFRACTORY PERIOD depolarization phase of action potential when sodium channels are opened a Another action potential cannot be generated 26 RELATIVE REFRACTORY PERIOD repolarization phase of action potential when sodium channels close potassium channels open a Strong stimulus can cause sodium channels to open sodium ion influx depolarization generation of another action potential STRUCTURAL CLASSES OF NEURONS 27 Multipolar at least 3 processes 1 axon and at least 2 dendrites most abundant neuron in human body 28 Bipolar 2 processes 1 axon and 1 dendrite 29 Pseudounipolar 1 short process from cell body bifurcates into central process peripheral process FUNCTIONAL CLASSES OF NEURONS 30 Motor Efferent transmits impulses AWAY FROM CNS to effector organs 31 Sensory Afferent transmits impulses from sensory receptors TOWARD 32 Association neurons interneurons located in CNS b w sensory neurons CNS and motor neurons a Most of neurons in body are association neurons 3 TYPES OF NERVE FIBERS 33 Group A fibers largest diameter heavily myelinated a Fastest conduction velocity 34 Group B fibers intermediate diameter lightly myelinated 35 Group C fibers smallest diameters unmyelinated THE BRAIN 4 PROTECTIVE STRUCTURES 36 Cranium bony helmet of 8 cranial bones frontal parietal temporal occipital sphenoid ethmoid 37 Meninges 3 connective membranes surrounding brain outermost double layered outer periosteal inner innermost clings to surface of brain 38 Cerebrospinal fluid CSF filtered from blood inside and outside of brain a DURA MATER meningeal b ARACHNOID MATER c PIA MATER middle Functions a Liquid cushion b Buoyancy to brain c Provides nutrients d Removes metabolic wastes 39 Blood brain barrier prevents harmful substances in blood from crossing to brain DEFINITIONS ventricle 40 Septum pellucidum median membrane that connects 2 lateral ventricles 41 Interventricular foramen channel that connects 2 lateral ventricles to 3rd 42 Cerebral aqueduct connects 3rd ventricle to 4th ventricle 43 LATERAL VENTRICLES in each cerebral hemisphere 44 3rd VENTRICLE in diencephalon 45 4th VENTRICLE in brain stem 4 REGIONS OF ADULT BRAIN 46 CEREBRUM 47 DIENCEPHALON 48 BRAINSTEM 49 CEREBELLUM CEREBRUM 50 Gyrus elevated ridge on surface of cerebrum 51 Sulcus shallow grooves on surface of cerebrum 52 Fissure deeper grooves 53 Corpus callosum holds together 2 cerebral hemispheres 54 Gray matter cell bodies dendrites makes up cerebral cortex 55 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 hemispheres a Ex Corpus callosum a Ex Pyramidal tracts a Ex Arcuate fasciculate 57 Projection tracts connect cerebrum to lower brain areas spinal cord 58 Association tracts connect areas within same cerebral hemisphere 5 LOBES IN CEREBRAL HEMISPHERE 59 Frontal lobe 60 Temporal lobe 61 Parietal lobe 62 Occipital lobe 63 Insula cannot be viewed externally deep to lateral sulcus 3 FUNCTIONAL AREAS IN CEREBRAL CORTEX 64 MOTOR AREAS voluntary movements a Primary motor cortex premotor cortex Broca s area frontal eye field b All located in frontal lobes 65 SENSORY AREAS conscious awareness of sensation a Primary somatosensory cortex primary visual cortex primary auditory cortex primary olfactory cortex primary gustatory cortex 66 ASSOCIATION AREAS integrate interpret sensory inputs from sensory 3 MAJOR BASAL NUCLEI islands of gray matter in cerebral white matter a LENTIFORM NUCLEUS putamen globus pallidus b CORPUS STRIATUM lentiform nucleus caudate 70 PARKINSON S DISEASE caused by degeneration of dopaminergic neurons to areas 67 Caudate nucleus 68 Putamen 69 Globus pallidus basal nuclei SPINAL CORD 71 Conus medullaris papery cone shaped structure that ends spinal cord 72 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 coccyx 74 Epidural space filled with fat and veins 75 Subdural space arachnoid mater separated from spinal dural sheath 76 Subarachnoid space separates arachnoid mater from pia mater a Contains CSF 77 Central canal core of spinal cord contains CSF from 4th ventricle in brain 78 Cervical enlargement superior spinal nerves innervate skeletal muscle in 79 Lumbar enlargement inferior spinal nerves innervate skeletal muscle in stem upper limbs lower limbs 80 TRANSECTION OF
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