How Nerves Work 3

Question 1

<p>What is a ligand?</p>

Answer 1

<p>A substance that forms a complex with a biomolecule</p>

Question 2

<p>What are some examples of graded potentials?</p>

Answer 2

<p>Generator potential (at sensory receptor)</p>

<p>Postsynaptic potential (at synapses)</p>

<p>Endplate potential (at neuromuscular junction)</p>

<p>Pacemaker potential (in pacemaker tissue)</p>

Question 3

<p>What is the job of the graded potential?</p>

Answer 3

<p>To get the cell to threshold and fire an action potential</p>

Question 4

<p>How are graded potentials decremental?</p>

Answer 4

<p>They don't trevel very well along membranes</p>

Question 5

<p>What does decremental mean?</p>

Answer 5

<p>Process of gradually becoming less</p>

Question 6

<p>Why are graded potentials decremental?</p>

Answer 6

<p>The current flows out of the graded potential as it travels along the axon</p>

Question 7

<p>What distance can graded potentials travel?</p>

Answer 7

<p>Only short due to being decremental</p>

Question 8

<p>How are graded potentials graded?</p>

Answer 8

<p>They may be of a higher intensity or a lower intensity</p>

Question 9

<p>What is the size of the graded potential proportional to?</p>

Answer 9

<p>The size of the stimuli</p>

Question 10

Show how graded potentials can be polarising or depolarising on a graph?

Answer 10

Question 11

<p>What is the threshold for opening Na⁺gated channels and firing an action potential?</p>

Answer 11

<p>-55mV</p>

Question 12

<p>What is an excitatiry post synaptic potential (EPSP)?</p>

Answer 12

<p>Anything that takes the potential towards threshold</p>

Question 13

<p>What is an inhibitory post synaptic potential (IPSP)?</p>

Answer 13

<p>Anything that takes the potential away from threshold</p>

Question 14

<p>What happens once a graded potential reaches threshold?</p>

Answer 14

<p>An action potential is fired</p>

Question 15

<p>How does a channel being part of the receptor affect the response?</p>

Answer 15

<p>Channel/receptor combinations produce a faster response, whereas if the channel uses a seperate receptor it produces a slower response</p>

Question 16

<p>What channels produce an IPSP response?</p>

Answer 16

<p>Cl^-(fast)</p>

<p>K⁺(slow)</p>

Question 17

<p>Do Cl^-channels produce a fast or slow response?</p>

Answer 17

<p>Fast</p>

Question 18

<p>Do K⁺channels produce a fast or slow response?</p>

Answer 18

<p>Slow</p>

Question 19

<p>What channels produce an EPSP?</p>

Answer 19

<p>Na⁺(fast, also permeable to K⁺due to them both having a charge of +1)</p>

<p>Closing leaky K⁺(slow)</p>

Question 20

<p>Do Na⁺channels produce a fast or slow response?</p>

Answer 20

<p>Fast</p>

Question 21

<p>Does closing leaky K⁺channels create a fast or slow response?</p>

Answer 21

<p>Slow</p>

Question 22

<p>What are presynaptic potentials generated by?</p>

Answer 22

<p>Neurotransmitter opening or closing ion channels</p>

Question 23

<p>Are graded potentials generated by ligand or voltage gated channels?</p>

Answer 23

<p>Ligand</p>

Question 24

<p>Are action potentials generated by voltage or ligand gated channels?</p>

Answer 24

<p>Voltage</p>

Question 25

<p>What is synaptic integration?</p>

Answer 25

<p>The summation of graded potentials to reach threshold</p>

Question 26

<p>Why are graded potentials generated next to the axon (where the axon potential is generated) more likely to reach threshold than one further away?</p>

Answer 26

<p>Graded potentials are decrimental</p>

Question 27

<p>What is temporal summation?</p>

Answer 27

<p>Stimulating the same potential one after an other</p>

Question 28

<p>What is spatial summation?</p>

Answer 28

<p>Stimulating two potentials at the same time</p>

Question 29

<p>What kinds of synapses can summate?</p>

Answer 29

<p>Both inhibatory and excitatory</p>

Question 30

<p>Where do synapses that are IPSP tend to be located?</p>

Answer 30

<p>On the soma</p>