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46 Cards in this Set
- Front
- Back
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How to neurons communicate? |
1) electrical signals within a neuron 2) chemical signals between neurons |
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what is the function of the cell body? |
site for synthesis of nearly all neuron's enzymes, structural proteins, membrane components, organelles, some neurotransmitters |
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explain the function of the nucleus |
control center, contains genetic material |
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explain the function of the ribosomes (Nissl substance or Nissl bodies) |
protein synthesis for cell use (when free) or neurotransmitters (when attahed to endoplasmic reticulum) |
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explain the function of the smooth endoplasmic reticulum |
lipid synthesis |
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explain the function of the rough endoplasmic reticulum |
protein synthesis |
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explain the function of the golgi apparatus |
packages neurotransmitters |
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explain the function of the mitochondria |
energy production |
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what are the structures and funcitons of the dendrite? |
Contains cytoskeleton, mitochondria, and dendritic spines. Fx: collect info from other neurons & increases surface area available for synaptic input |
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what are the structures & functions of the cell body or soma? |
S: nucleus, golgi apparatus, nissl substance, cytoskeleton, mitochondria, axon hillock Fx: synthesize macromolecules & integrate electrical signals |
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what are the structures & functions of the axon? |
S: cytoskeleton, mitochondria, transport vessicles, less than 1 mm to 1 m long,initial segment, most covered in myelin, glial membranes (motor long) Fx: conduct information to other neurons (single output unit of neuron), transmit Action Potentials, |
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what are the structures & functions of the axon terminals or synaptic endings? |
S: synaptic vesicles, mitochondria Fx: transmit info to other neurons |
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What does exersice stimulate? |
new neuron birth & mitochondria= protect from neurodegenerative diseases |
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what is a dendritic spine? |
spiky protuberance that are preferred sites for synaptic inputs |
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explain the structure & function of the cytoskeleton |
S: network of protein filaments contained in nearly all parts neuron F: give neurons shape & assist in transport (microtubules, neurofilaments, microfilaments) |
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Explain axonal transport |
1) fast anterograde transport: material travels from cell body-> presynaptic terminal along microtubules 2) Slow anterograde transport: soluble proteins 3) Fast Retrograde Transport: material travels from synapse back to cell body alon microtubules |
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what are clinical conditions related to axonal conditions |
1) Poliovirus (gains access CNS via fast retrograde causing poliomyelitis) 2) Herpes virus (gains access to soma via retrograde transport) 3) Chemotherapy (stops cell division & axonal transport may = neuropathies/cancer pain) 4) Alzheimer's disease (AD) (amyloid plaques, neurofibrillary tangles cause by problem with tau protein on microtubules) 5) Chronic Traumatic Encephalopathy (CTE) progress degenerative brain disease (athletes) with repetitive brain trauma- symptomatic concussion/asymptomatic subconcussive hits, same neurofibrillary tangles in AD |
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What are neuron shape classifications? |
1) Multipolar 2) Bipolar 3) Psuedounipolar |
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what is the most common neuron shape in vertebrates? |
multipolar! they are designed to receive and accommodate large amounts of input |
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which shape is a subclass of another? |
Pseudounipolar is a subclass of bipolar neurons |
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what are the function classifications of neurons? |
1) sensory neurons (directly or with connection with receptor cells) 2) motor neurons (muscles, glands, other neurons) 3) interneurons (small area in CNS) 4) projection neurons (neurons in CNS with long axons project to another part of CNS) |
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what function neurons lie partly in the CNS & PNS? |
sensory and motor |
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What functional neurons comprise more than 99% of neurons in our bodies? |
Interneurons & projection neurons |
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what is synaptic transmission? |
mechanism which neurons commnicate with each other/glands/muslces. This is done through the synapse. |
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what is the presynaptic element? |
distal end of axon |
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what is the postsynaptic element? |
part of another neuron |
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what is the synaptic cleft? |
separation between two elements |
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what is a synaptic vesicle? |
neurotransmitters released from presynaptic element into the cleft and bind to receptor sites in postsynaptic membran, causing an electrical signal in postsynaptic neuron |
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what are the types of CNS synapses? |
1) Axodendritic: axon 1 cell to dendrite of another (most common in CNS) 2) Axosomatic: axon to soma 3) Axoaxonic: axon to axon 4) Dendrodendritic: dendrite to dendrite |
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whats the principle glial cell in the PNS? |
schwann cells |
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Explain Schwann cells |
Purpose: 1) metabolic support 2) electrical insulation. -They wrap around most individual axons for myelination: electrochemical sheating of axons (speeds AP conduction) -1 cell myelinates 1 internode around axon -rolls up around azon |
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what are the glial cells in the CNS? |
1) Oligodendrocytes 2) protoplasmic astrocytes 3) fibrous astrocytes 3) microglia 4) ependymal cells |
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explain oligodendrocytes |
location: white & gray matter fx: form myelin sheath * counterpart to Schwann BUT 1 oligo can produce seceral internodes on several axons |
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explain protoplasmic astrocytes |
location: gray matter fx: mechanical/metabolic support, response to injury= "carpet" over capillaries & neurons to control CNS environment & transfer metabolites to and from neurons/synaptic cleft, astrocytic scar * star shapped, largest of glial |
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explain fibrous astrocytes |
location: white matter fx: provide mechanical/metabolic support, response to injury= "carpet" over capillaries & neurons to control CNS environment and transfer metabolits to and from neurons/synaptic cleft, astrocytic scar * star shaped, largest of glial |
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explain microglia |
location: gray & white matter fx: phagocytosis= CNS "immune system", response to injury to migrate and clean up debris *smallest CNS glia |
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explain ependymal cells |
location: walls ventricles fx: line ventricles & choroid plexus, facilitate flow of CSF, SECRETE CSF, involved in blood-CSF barrier |
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what's a glioma? |
tumor of glial cell origin |
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Tumors in PNS usually? |
schwann cell: schwannoma (encapsulated with no nerve fiber involvement=easy remove) or neurofibroma (encapsulated infiltrating nerves=difficult remove) |
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what are the majority of brain tumors? |
astrocytic (astrocytoma) |
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what is a grade IV astrocytoma? |
Glioblastoma multiforme |
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How to you treat gliomas/tumors? |
1) cancer treatment (chemo, radiation, surgical removal) 2) insert chemo/radiation seeds in cavity where tumor is 3) antiangiogenesis: cut blood supply to tumor 4) create vaccine from tumor cells and use body's immune system to gith it 5) "deactivated" polio virus attacks tumor |
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explain myelin |
-critical to conduction in nervous system -created from oligodendrocytes & schwann cells -made of lipid substance (white) -insulates axon to improve velocity & efficiency of AP |
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Explain PNS demyelination |
etiology: autimmune disorder, metabolic abnormalities, viruses, trauma, and toxic chemicals ex: Guillain-Barre syndrome (GSD |
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what is Guillain-Barre syndrome (GBS)? |
-acute inflammation and demyelination of peripheral sensory (some) and motor (mostly) fibers -thought to be autoimmune: immune generates antibodies that attack Schwann cells -prognosis: depends on severity (myelin sheath vs anxonal involvement)=most people can have near full recovery -treatment: plasmapheresis (filter plasma); intravenous immunoglobulin therapy (neutralize antibodies/reduce inflam), rehabilitation/thearpy |
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explain multiple sclerosis (MS)? |
autoimmune disease: body produces antibodies attack oligodnedrocytes etiology: not understood= genetic w/environmental trigger -areas of demyelination replaced by astrocytic plaques = slowed/blocked AP Prognosis: variable- some resolve, some linger Tx: immunosuppressants, pharmacological, |
