action potentials

Question 1

aspects of resting membrane potential
-range
-potassium and sodium range insdie and outisde neuron

Answer 1

-70Mv
potassium is more pearmeable than sodium leading to a more negative charge inside, due to leak channels allowing their passage

Question 2

how does the membrane potential change?

Answer 2

opposite changes attract.
-pottassium is higher on insdie as its pulled back due to negative environment

Question 3

what is depolorisation during an action potential
what is repolarisation after an action potential

Answer 3

voltage gated sodium channels open membrane becomes more positive.
due to a sodium influx in the cell

-voltage gated pottasium channels open making membrane becomes more negative. due to potassium leaving the cell

Question 4

what happens when during an action potential with sodium

Answer 4

ion channels are triggered to open.
mostly occurs to sodium positive channels which is key to generating a nerve impulse.

Question 5

difference between a graded and action potential

Answer 5

graded potential: a weak small synaptic signal from another neuron that may or may not trigger an action potential

action potential: a nerve impulse travelling down an axon to release neurotransmitters.

Question 6

1)what is a ligand gated channel
2) what is leak channels
3) what is voltage gated channel

Answer 6

channels that open or close in response to binding of a ligand molecule. allows sodium and calcium to flow into cells

2) allow pottassium to flow into cell which results in negative membrane at rest

3) allows sodium to flow into membrane during action potential making it more positive

Question 7

difference between Excitatory Postsynaptic Potentials (EPSPs) and Inhibitory Postsynaptic Potentials (IPSPs)

Answer 7

EPSP= is a depolorisation of post synpatic membrane making the membrane more likley to fire an action potential
IPSP= is a hyperpolorisation of post synpatic membranr making the membrane less likley to fire an action potential

Question 8

difference between spatial and temporal summation

Answer 8

spatial= ultiple presynaptic neurons sending signals to multiple locations on postsynaptic neuron. ESPS?ISPS from multiple neurons combine
temporal= a single presynaptic neuron rapid firing repeadidly. repeated ESPS/ ISPS add up over time leading to a stronger response.

Question 9

Be able to explain the sequence of events and constituent components involved in action potential generation.

Question 10

movment of different ions

Answer 10

sodium- mainly found outisde cell
potassium- found inside cell
calcium- present low concentrations inside cell and higher concentrations outside the cell

Question 11

what affects the rate of conduction of action potential along a nerve fibre

Answer 11

1) mylein
2) nerve diameter
3) temperature

(not length)

Question 12

two types of synapse transmissions
1) chemical
2) electrical

Answer 12

1) slower due to release and binding of neurotransmitter in pre and post synpase. allows calcium influx in pre synaptic terminal
2) faster due to gap junctions allowing direct flow of sodium and pottassium

Question 13

what stimulates the release of a neurotransmitter

Answer 13

1) action potential
2) calcium influx in presynaptic terminal

Question 14

what conduction occurs in myleinated axons

Answer 14

saltatory conduction - jumps from one axon node to the next