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48 Cards in this Set
- Front
- Back
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3 Layers of Neural Tube
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Ventricular zone or ependyma a
intermediate zone marginal zone |
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ventricular zone or ependyman
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found around lumen (central canal of the tube
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intermediate zone
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formed by dividning of ventricular zone and stretches between ventricular surface and outer pial layer
becomes gray matter |
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external marginal zone
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process of nerve cells in the intermediate zone
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dendrite
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receptive part of neuron
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conduting (propagating or transmiting)
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axon
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end of axon
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synaptic terminal or arborizations,
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Neuron's cell body
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called soma or perikaryon
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axon aries from
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neurons
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axon is coverbed by a membrane
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axolema
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Cytoskeleton consist of
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neurofilaments and microtubules runs through the axon
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Microtubules provide a
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framework for fast axonal transport
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specialized molecules motor
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kinesin molecules ATP
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axolema cotains high density of sodium
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act as trigger zone
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axon hilloc- cone shaped portion of the cell
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found in large neurons
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myelin
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axon are covered by
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axon is mutiple concentric layers of lipid-rich membran produced by Schwann cells in
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PNS
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oligodendrocytes
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CNS for axon
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Myelin sheath is divided into segment
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Nodesof Ranvier
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smallest axon
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unmyelinated
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from synaptic terminals to the cell body
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retrograde transport
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anterograde transport
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from cell body to the synaptic terminal
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after injury to the axon, the neuronal cell body responds by enterign
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axon reaction or chromatolysis
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CNS
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axon can not generate after injury
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PNS
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axon can generate after injury
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Communication
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Synaptes
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axosmatic
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inhibitory
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electrical synapese or gap junctions
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chemical transmiters subtannce in CNS
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transmters
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acetylcholine and catechloamine
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Laminas
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Cerebral and cerebellar cortices, cell bodies aggregate to form layers called
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Nerve cell bodies in the spinal cord, brain stem, and cerebrum form
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compact groups, nuclei
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Each nucleus contains
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projection neurons
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Peripheral nervous system, compcact groups of nerve cell bodies are called
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ganglia
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axon bundles are identified
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tracts or fasciculi
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aggregates of tracts in the spinal cord are
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columns or funiculi
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neutropil
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axons are intermingled with dendrites and do not run in bundles so that pathways are difficult to identify
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Neuroglia
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____ outnuber neurons in the brain and spinal cord 10:1
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Neuroglia cells
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do not form synapses, appear to play important roles in myelin formation, guidance of developing neurons, maintenance of extracellualr K, reuptake of transmitters
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Macroglia
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refers to astrocytes and oligodendrocytes derived from ectoderm, capablity to regenerate
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two classes of astrocytes
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Protoplasmic and fibrous
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Protoplasmic astrocytes are
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delicate, occur in gray matter or satellite cells in dorsal root ganglia
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Fibrous astrocytes are
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fibrous, contain glial fibrils,
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astrocytes
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surround blood vessels in nervous system, cover exterior surface of brain and spinal cord
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astocytes maintain K concentration within extracellular, contribute formation of the blood-brain barrier, can take up material to provide optimal environment
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astrocytes
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astrocytes contain protein
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glial fibrillary acidic protein
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Chronic astrocytic proliferation leads to
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fibrillary gliosis or glial scarring
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Oligodendrocytes
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white matter; they form myelin in the CNS and provide nutritive support to the neurons they envelop
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A single oligodendrocytes may wrap around mutliple axons
T or F |
True, an oligodendrocytes may myelinate up to 40-50
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