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52 Cards in this Set
- Front
- Back
Gray Matter=
White Matter= |
mostly cell bodies
mostly axons |
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Nuclei=
cortex= |
clusters of neurons
layers of neurons |
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Neurons are terminally....
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differentiated. lack capacity for cell division after prenatal development. CNS can't regrow. PNS can sometimes regrow depending on damage
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name the 4 main parts of the neuron
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dendrites, cell body (soma), axon, synaptic bouton
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Dendrites contain fine filaments, ___, ___, and ____. Also have ____
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mitochondria, RER and free ribosomes. also have spines
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dendritic spines are what? associated with?
density correlated with? |
small lateral projections along dendrite shaft associated with synaptic contacts.
density correlated with greater synaptic capacity and efficacy |
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Soma is what? used for?
abundant in? |
cell body, metabolic support for cell, abundant RER (lots of protein synthesis) and mitochondria
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axons do what? abundant in? don't have what? what are the side branches called?
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conduct/carry action potentials
abundant in microtubules some mitochondria, NO RER side branches=collaterals |
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Axonal Transport what is it? what are the 2 types?
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electrical mechanism to move molecules and organelles along inside the axon.
anterograde (orthograde): molecules made in soma transported to needed place in axon retrograde: take up molecules at boutons and transport toward soma |
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Orthograde/Anterograde uses what protein?
Retrograde uses what protein? |
Kinesin
Dynein |
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Alzeimhers disease has less of what two types of synapses?
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perforated and multiple spine boutons
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Convergence
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single neuron receive input from many sources/neurons. motor neurons
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divergence
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axon of neuron branches to affect cells in many different locations. sensory system.
5-10x more sensory neurons than motor |
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Afferent vs. Efferent Neurons vs. Inter Neurons
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Afferent=carry signals into the CNS from Sensory cells (A=Arrives at CNS)
Efferent=carry signal from CNS to muscles/glands (Exits CNS) Interneurons=interconnect groups of neurons in CNS. Most neurons in brain are inter |
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unipolar
Bilpolar Multipolar: Spherical vs. Planar (Pyramidal, Purkinje, motor) |
-smallest nerve cells. invertebrates.
-two sets of processes extending from opposite sides of cell -multipolar: most common, branched processes. one axon, rest dendrites |
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Nissl Bodies
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Large amounts of RER in soma used for protein synth needed to maintain healthy neuron
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Chromatolysis results in what?
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neuron injured: cell becomes pale, swells, loss of Nissl Staining, protein synth increased, RER dispersed, Nucleus becomes large, vesicular, moves to margin of cell
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What diseases are associated with chromatolysis?
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ballooned neurons seen in ALS, Alzheimers, pellagra, prion disease, pick's disease,
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Neuromelanin
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present only in humans, possible byproduct of neurotransitter synthesis, parkinsons presents a loss in neuromelanin
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Neuroglia
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glue which hold brain together, important supportive functions for neurons
90% of cells in brain are glia, 50% of volume of neural tissue, smaller than neurons Einstein had lots! |
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Function of Glial cells
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-maintain ionic milieu
-modulate signal -propagation/synaptic action -uptake of neurotransmitter -provide scaffolding -aid in damage recovery |
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4 types of glia
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astrocytes: maintain environment
ependymal: line ventricles, CSF oligodendrocytes: form myelin microglia: phagocytic |
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Glia develop how?
what function do they maintain? |
stem cells--->neuroblasts (neurons) and glioblasts (glia)
CNS glioblasts->glia in ventricular zone of neural tube PNS glia come from stem cells in neural crest neuroglia retain ability to prolifeerate under certain stimuli |
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Astrocytes help do what?
2 main types |
star shaped-help regulate internal environment around neurons
ex.) uptake of glutamate/BBB barrier Protoplasmic=stubby, gray matter Fibrous=long, thin, IF, white matter |
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Ependymal cells
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line the fluid-filled ventricular spaces of the brain
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Oligodendrocytes
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elaborate myelin around CNS axons
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microglia
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phagocytes
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Oligodendrocytes are in the ____ and make _____
Schwann cells are in the _____ and make _____ |
oligo=CNS, produce myelin
schwann=PNS, produce myelin |
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Astrocytes takes up free ____ and maintain ____
Abundant in____ spread through glial cells via____ |
K+ and maintain inactive field (constantly active field is toxic) also regulate water and ionic balance in CNS
abundant in Na+/K+ pumps gap junctions |
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ALS and glia
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ALS=dysfunction of glutamate uptake transporters->hangs out in synaptic cleft with nowhere to go
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Glia guide _____, induce _____ to make the _____
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axons, induce tight juctions (when contact capillaries) to make the BBB
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Radial glia=
glia secrete ____ and ____ to guide CNS development |
scaffolding for neurons,
trophic molecules and surface proteogylcans |
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BBB upside/downside
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up: isolation of brain from toxic/blood borne molecules
down: difficult to get therapeutic agents to CNS |
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astrocyte reaction, what happens? results in?
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response of astrocytes to tissue damage by enlarging, proliferating, increasing metabolic activity, phagocytosis,
results in glial scar |
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Ependymal calls line____, joined together by____
Help to circulate____, which is secreted by____ |
ventricles/cavities of the brain, joined together by tight junctions
CSF via cilia, secreted by Choroid Plexus (look like grapes in the ventricles) |
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1 schwann cell: #? nerve axons?
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1
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1 oligodendrocyte: #? nerve axons?
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LOTS!
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Multiple Sclerosis is due to
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demylination
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myelin proteins PNS vs. CNS
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PNS: protein zero (glycoprotein in schwann cells) myelin basic protein ("glue", essential for compaction) and
CNS: Proteolipid protein (PLP), Myelin Basic protein |
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Microglia
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inflammatory response to cell damage, get "angry", enlarged, short/stubby
relaxed=small cell body with long processes |
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Inflammatory Theory on Aging
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cytokkine levels elevated in aged individuals, body less able to handle infections
-AD, ALS and PD both correlated with neuroinflammation |
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Knee jerk reflex is testing what? what kind of system is it?
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monosynaptic muscle stretch reflex. two-neuron system=afferent-motor neuron=all or none response
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PNS runs...
what exists only in the PNS? |
throughout the body.
nerves. |
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PNS comes from what?
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Neural Crest Cells
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PNS is a collection of ?
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neuronal cell bodies called ganglia
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3 components of the PNS
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1)sensory (afferent)
2)motor (efferent) 3)visceral/autonomic motor=smooth, cardiac, secretory muscles/glands -what is the autonomic nervous system composed of? |
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What is the ANS composed of? what is the ANS part of?
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the Sympathetic nervous system "flight or fight"
and the Parapsympathetic nervous system=parachute, rest/digest and the Enteric Nervous system=digest=contraction of the gut ANS is part of the PNS |
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CNS=
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brain and spinal cord
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CNS derives from...?
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the neuroectoderm
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clumps of neruons in the CNS are called
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nuclei
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the entire CNS is protected by
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bone
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Components of the spinal cord
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sensory neurons, motor neuron cell bodies, pre-ganglionic sym/parasym neurons, interneurons, ascending sensory/descending motor tracts
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