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52 Cards in this Set
- Front
- Back
What is a neuron
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receive information and transmit it to other cells
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What is a membrane
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the structure that separates the inside of the cell from the outside environment
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What is the nucleus
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the structure that contains the chromosomes
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What is the mitochondrion
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the structure that performs the metabolic activities
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What are ribosomes
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they are the sites at which the cell synthesizes new protein molecules
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What is the ER
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a network of thin tubes that transport newly synthesized proteins to other locations
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what is a soma
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cell body
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What is a motor neuron
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has its soma in the spinal cord. It recieves excitation from other neurons through its dendrites and conducts impulses along its axon to muscles
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What is a sensory neuron
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Specialized at one end to be highly sensitive to a particular type of stimulation
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What is a dendrite
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it recieves information
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What are dendritic spines
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short out growths that increase the surface area available for synapses
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What is the axon
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information sender
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What is a myelin sheath
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it speeds the transfer of information
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What are the nodes of Ranvier
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they are spaces in the myelin sheath that messages jump across
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What is the difference between an afferent axon and an efferent axon
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Afferent brings information into a structure(sensory) Efferent carries information away from a structure(motor)
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Interneuron
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If a cell's dendrites and axon are entirely contained within a single structure
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What are glia
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They give nutrition and protect neurons
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What is an astrocyte
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it wraps around the presynaptic terminals of a group of functionally related axons
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What are Microglia
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very small cells, also remove waste material as well as viruses, fungi, and other microorganisms they function like the immune system
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What are Schwann cells
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specialized types of glia that build the myelin sheaths that surround and insulate certain vertebrate axons
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What are Radial glia
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type of astrocyte guide the migration of neurons and the growth of their axons and dendrites during embryonic development
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What is the blood brain barrier
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the mechanism that keeps most chemicals out of the vertebrate brain
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What is the area postrema
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an area that monitors blood chemicals that could not enter other brain areas causes vomitting and other responces. (once a virus enters the brain it is always there
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What are the two categories of molecules that cross the blood brain barrier
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small uncharged molecules such as oxygen and carbon dioxide and water
molecules that dissolve in the fats of the membrane like vitamins and drugs like weed |
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What is active transport
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a protein mediated process that expends energy to pump chemicals from the blood into the brain
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What is an electrical gradient
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a difference in electrical charge beetween the inside and outside of the cell
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What is polarization
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a difference in electrical charge between two locations
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What is the resting potential
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difference in voltage in a resting neuron
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What is a nerve
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a bundle of axons outside the CNS tract
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What is a nucleus
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cell bodies inside the CNS
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What is a tract
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a bundle of axons inside the CNS
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What is a ganglion
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cell bodies outside the CNS
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What is the sodium potassium pump
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a protein complex that repeatedly transports three sodium ions out of the cell while drawing two potassium ions into it. It is active transport
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what is a concentration gradient
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the difference in distribution of ions across the membrane
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Which ion is more prevalent inside the cell
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potassium
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Threshold excitation
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massive depolarization
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What are voltage activated channels
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membrane channels whose permeability depends on voltage difference across the membrane
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How does the pump work
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an action potential comes across the sodium channel opens and the sodium rushes in the potassium opens to and potassium rushes out the diffusion reverses
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What are drugs such as Novacane that attach to the sodium channels of the membrane preventing sodium ions from entering blocking the action potential
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Local anesthetic
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Do dendrites produce action potentials
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no axons do
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the amplitude and velocity of the action potential is independent of the intensity of the stimulus
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all-or- none rule
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What is the period after the action potential which the cell resists production of further action potentials
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the refractory period
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No stimulus is allowed during this period
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absolute refractory
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A swelling where the axon exits the soma also starts the action potential
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the axon hillock
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Propagation of the action potential
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transmission of the action potential down the axon
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myelin
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insulating material found only in vertebrates composed of fats
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What is the saltatory conduction
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the jumping of action potentials from node to node sodium is admitted only at the nodes
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What are local neurons
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neurons that have short axons and communicate with neighbors
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What are graded potentials
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membrane potentials that vary in magnitude and do not follow the all or none rule local neurons
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What are reflexes
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automatic muscular responses
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What is a reflex arc
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the circuit from sensory neuron to muscle
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What is temporal summation
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repeated stimuli within a time have accumulated affect
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