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23 Cards in this Set
- Front
- Back
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Membrane potential (#10) |
is mostly negative for all cells except when there is a change in membrane permeability to ions |
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Types of Transporters (#16) |
Channel proteins: Ex) Gated and open channel Carrier proteins: uniport, symport, antiport Voltage gated (voltage dependant) channels |
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The resting potential of a typical nerve cell is.... |
negative 70 mV |
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What gates allow sodium ions to bypass? (#25) |
Chemical (ligand controlled) Mechanical ( temp and pressure controlled) Voltage gates (electrical signal controlled) |
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When a neuron changes ion permeability(#26) |
a variety of gated ion channels open and close. Na+ channels may open, allowing Na+ to enter the cell |
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How does increased glucose availability in a pancreatic beta cell and closure of the KATP channel lead to exocytosis of insulin-containing vesicles? (#20) |
Closure of KATP channels causes membrane depolarization and the opening of voltage-gated Ca2+ channels. |
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100% of the glucose should be absorbed into the cell from the interstitial fluid. Why does nearly all of the glucose enter the cell, rather than only half of it? (#116) |
It is modified by the cell, so there is still more glucose on the outside of the cell than inside it. |
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The total amount of neurotransmitter released at the axon terminal is directly related to (34) |
The total number of action potentials |
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The inhibitory neurotransmitters of the CNS, GABA and glycine, act by opening ________ channels. |
only Cl- |
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Once the stimulus alters the receptor on the cell's membrane, what happens next? |
Ion channels open, allowing ions to enter or exit.
The membrane permeability is altered.
A second messenger is activated on the inside of the cell. |
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In response to binding a neurotransmitter, a postsynaptic cell can |
open chemically gated ion channels, causing graded potentials known as fast synaptic potentials, close ion channels via G proteins and second messenger systems, producing slow responses, and regulate protein synthesis and affect the metabolic activities of the postsynaptic cell. |
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which synapse is the only one with direct physical connection between cells? |
electrical |
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Inhibition of neural activity can result from |
presynaptic events and postsynaptic events. |
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Receptors that work through second messenger systems are called ________ receptors. |
metabotropic |
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Which two properties determine the conduction velocity in a mammalian neuron? |
Axon diameter and the leak resistance of the membrane |
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How synapses work |
1) an action potential arrives at synaptic terminal 2) calcium channels open, and ions enter the synaptic teriminal 3) vessicles containing neurotransmitter fuse with the plasma membrane of the sending neuron. 4) neurotransmitter molecules diffuse across the synaptic cleft 5) the neurotransmitter molecules bind to receptors in plasma membrane causing ion channels to open |
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The resting membrane potential results from |
uneven distribution of ions across the cell membrane and differences in membrane permeability to Na+ and K+. |
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Which ion(s) is/are higher in concentration inside the cell compared to outside? |
Potassium K |
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The rising phase of the action potential is due to... The falling phase of the action potential is due primarily to .... |
Sodium Na+ = rise Potassium = fall |
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The absolute refractory period of an action potential |
ensures one-way travel down an axon, allows a neuron to ignore a second signal sent that closely follows the first, and prevents summation of action potentials. |
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In order to signal a stronger stimulus, action potentials become |
more frequent only |
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Action potentials are primarily associated with the membranes of |
Axons |
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graded potential |
can hyperpolarize, can involve ion channels regulated by chemicals, for the graded proffs. size will increase if stimulas str increases |
