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70 Cards in this Set
- Front
- Back
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What are the two basic types of cells in the nervous system?
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Neurons and Glial Cells
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Neurons- are they white or gray matter?
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gray matter
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How many neurons do we have? What about if we add supporting cells?
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We have 100 billion neurons and with supporting cells added we have about 1 trillion
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Neurons- where do they carry info to?
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Within the neuron they carry info from one part to another, they also carry info between neurons
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What do neurons do?
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convey information
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T or F- Each neuron has a cell body (soma, gray matter)
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True
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What kind of signals do neurons use?
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chemical and electric
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Dendrites- what are they?
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extensions of the cell body that recieve incoming info- takes towards cell body
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Are dendrites afferent or efferent?
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afferent
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Afferent
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receive incoming info, take towards cell body
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T or F- each cell can have many dendrites
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T
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Axon- describe how it looks, what it does
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A long, cylindrical process, transmits info away from the cell body (efferent)
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efferent
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transmits info away from cell body
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axon hillock
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origin for where axon takes off
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T or F- An axon can only have one branch
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F-an axon can have many branches
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Terminal boutons are associated with what?
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axons
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what are the types of neurons in the PNS and CNS with regard to projections? What do they mean?
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- monopolar: one projection
- bipolar: 2 projections - multipolar- many projections |
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What is the PNS?
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Peripheral Nervous System- spinal and cranial nerves
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What is the CNS?
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Central Nervous System- brain and spinal cord
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What two divisions can we divide the brain into?
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white and grey matter
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Gray Matter
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- cell groupings, highly vascular
- contains interneurons - collection of cell bodies |
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White Matter
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- collection of axons
- ascending pathways from cerebellum, brain stem, spinal cord - descending pathways to brainstem, cerebellum to spinal cord |
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What are the parts of the synapse?
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- axon (axonal ending)- forms pre-synaptic side
- dendridic zone- forms post-synaptic side - synaptic cleft is in the middle |
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What is a synapse?
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A connection between an axon and a dendrite
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Synaptic Transmission
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- chemical event
- vesicles at end of terminal boutons - contain neurotrasmitters- chemical - carries info across synaptic cleft |
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What are the neurotransmitter chemicals with regard to synaptic transmission?
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serotonin, dopamine, acetylcholine, nor-epinephrin
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What are the two different ways we can categorize neurons?
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1. by function
2. by diameter of the axon |
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What are the three functional divisions of neurons?
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1. sensory- afferent
2. interneurons- connect 3. motor- efferent |
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sensory neurons
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- bring info into the CNS
- pain, touch, temperature changes |
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interneurons
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- small, all they do is connect 2 neurons to eachother
- subcorital, spinal cord |
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motor neurons
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- efferent
- info going out - ends on muscles, glands |
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Diameter of an axon is directly related to what?
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speed of transmission. Largest fibers are faster.
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T or F- axons travel in several directions
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F, axons travel in only one direction, known as nerve tracts
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Glial Cells- what do they do?
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Glue to support neurons, holds things together, garbage collectors that regulate extra cellular fluid
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What are the 2 types of glial cells we learned about?
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Oligodendroglia and Schwann cells
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Oligodendroglia
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a type of glial cell, manufactures myelin in the CNS
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Schwann cells
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a type of glial cell, manufactures myelin in the PNS
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What is myelin made of?
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lipids and protein in alternate layers and segments.
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When is myelin made?
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It is made by glial cells during periods of rapid development
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What does myelin do?
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it wraps around axons and insulates and speeds transmission of neural impulses. No fine motor coordination until myelination
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When does the majority of myelin sheath in the cerebrum and cerebellum form?
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during the 1st year of life.
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With regard to earlier and later ages how does myelin form?
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early- fetus, period of rapid growth- form for sucking action
later- fine motor, complex mental activity |
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MS
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chronic degenerative disease. Gradual distruction of myelin in brain and spinal cord.
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Nodes of Ranvier
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spaces between segments of myelin on axon. Flow of impulses jumps node-to-node=salutory motion.
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With regard to salutory motion what do we mean by all or nothing?
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nerve will pick up info or it won't- it the nerve is tired it won't transmit. Doesn't ever partially transmit- either does or doesn't.
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What are neurotransmitters?
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chemical substances released at the end of axons (at terminal bouton)
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What do neurotransmitters do?
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they are released into the synaptic cleft and induce electrical change into the dendritic end. They can be inhibitory or excitory.
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How many neurotransmitters are known?
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over 30
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nor-epinephrin- what is it involved in?
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sympathetic nerve endings
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dopamine- what is it involved in? What medical conditions is it associated with?
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Regulates reward- "dopamine jolt"-p craving, motivation, goal oriented behavior, ecstasy. Conditions associated with are schizophrenia and parkinson's.
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Serotonin- what is it associated with?
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depression
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acetylcholine- what does it do?
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neuromuscular junctions, memory
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electrical signals- where do they carry info?
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from one part of neuron to another part
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chemical signals- where do they carry info?
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between neurons
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how do neurotransmitters work? Describe the process of what happens
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1. action potential at axon hillock
2. myelin speeds up propogation 3. jumps from node to node 4. chemical substance released into synaptic cleft 5. induces electrical event in dendrite- excitatory or inhibitatory |
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What are other names for grey matter?
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nucleus, ganglion, lamina, cortex, body, horn
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cortex
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outer layer (thin). type of grey matter.
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horn
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spinal cord gray matter
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axon terminals- are they part of grey matter or white matter?
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grey matter- but axons are white matter
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glial cells- are they grey or white matter?
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grey matter
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white matter is primarily bundles of _________ from many cells
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axons
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T or F- white matter includes cell bodies?
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false, cell bodies are grey matter
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What are other names for white matter?
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tract, fisciculus, brachium, peduncle, commissure
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peduncle
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bundles of fibers, connecting cerebellum to spinal cord
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commissure- what is another name for it and what is it?
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aka Corpus Callosum. Unites the two hemispheres. .Largest fiber bundle in the brain.
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What is the left hemisphere responsible for (in general)?
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speech/language, analytic, verbal, complex motor functions
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What is the right hemisphere responsible for (in general)?
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visual/spatial orientation, tactile, perceptual, some language, music
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Do the right and left hemipheres work together?
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yes, but each is still dominant for certain activities
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Is the asymmetry of the hemispheres learned or innate?
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innate
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When do some studies suggest that lateralization of speech/language processing is complete (age)?
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age 3
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