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

What is synaptic integration?

Answer 25

The summation of graded potentials to reach threshold 

Question 26

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

Answer 26

Graded potentials are decrimental

Question 27

What is temporal summation?

Answer 27

Stimulating the same potential one after an other

Question 28

What is spatial summation?

Answer 28

Stimulating two potentials at the same time

Question 29

What kinds of synapses can summate?

Answer 29

Both inhibatory and excitatory

Question 30

Where do synapses that are IPSP tend to be located?

Answer 30

On the soma