bio urgent question, tomorrow DAT retake!!! help

[joey2007]

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1. Which of the following fates does NOT happen to a neurotransmitter after it is released at a synaptic cleft in the CNS?a. the neurotransmitter binds to and opens a gap junction between the pre- and postsynapticneuronsb. the neurotransmitter may diffuse across the cleft and bind to a ligand-gated ionchannel on the post-synaptic membranec. any neurotransmitter that is not bound to some type of receptor may be degraded ortaken up again by the presynaptic terminald. the neurotransmitter may bind to an autoreceptor located on the presynaptic terminaland thereby inhibit further neurotransmitter releasee. a and d2. If an electrode is placed in the middle of a resting axon and an above-threshold voltage isapplied, action potentialsa. will not occur.b. will start at that point and travel in all directions across the axon.c. will start at that point and proceed only toward the axon terminal.d. will start at that point and proceed only toward the cell body.

 

[doc3232]

Your post came out messy so it is tough to read.

Firstly, I think the neurotransmitter binds to the post synaptic cell and from there ions flow in. But the ions come from the cell environment NOT from the presynaptic cell. I do not think any channel ever opens between the two cells.

 

[annguyen293]

So did you finish DAT? How is it? I hope you did well

 

[chessxwizard]

If an electrode is placed in the middle of a resting axon and an above-threshold voltage isapplied, action potentials
a. will not occur.
b. will start at that point and travel in all directions across the axon.
c. will start at that point and proceed only toward the axon terminal.
d. will start at that point and proceed only toward the cell body.

b. Remember, the only reason why an action potential is one way when it starts at the axon hillock is because there are no voltage gated channels in the soma. Thus it starts going down the axon and, due to the refractory period, can't go back. But if it starts half-way down the axon, it can go both ways since there are voltage gated channels in either direction. However, it cannot go backwards towards the starting point due, again, to the refractory period.

Kinda late response, I know... but I hope it helps some other people...

 

[dl9006]

1. Which of the following fates does NOT happen to a neurotransmitter after it is released at a synaptic cleft in the CNS?a. the neurotransmitter binds to and opens a gap junction between the pre- and postsynapticneuronsb. the neurotransmitter may diffuse across the cleft and bind to a ligand-gated ionchannel on the post-synaptic membranec. any neurotransmitter that is not bound to some type of receptor may be degraded ortaken up again by the presynaptic terminald. the neurotransmitter may bind to an autoreceptor located on the presynaptic terminaland thereby inhibit further neurotransmitter releasee. a and d2. If an electrode is placed in the middle of a resting axon and an above-threshold voltage isapplied, action potentialsa. will not occur.b. will start at that point and travel in all directions across the axon.c. will start at that point and proceed only toward the axon terminal.d. will start at that point and proceed only toward the cell body.

if you want people to help you with your question then the least you could do is post the question in a way that people can actually read it...

 

[ZenoVT]

There we go!

1. Which of the following fates does NOT happen to a neurotransmitter after it is released at a synaptic cleft in the CNS?

a. the neurotransmitter binds to and opens a gap junction between the pre- and postsynaptic neurons

b. the neurotransmitter may diffuse across the cleft and bind to a ligand-gated ion channel on the post-synaptic membrane

c. any neurotransmitter that is not bound to some type of receptor may be degraded or taken up again by the presynaptic terminal

d. the neurotransmitter may bind to an autoreceptor located on the presynaptic terminal and thereby inhibit further neurotransmitter release.


2. If an electrode is placed in the middle of a resting axon and an above-threshold voltage is applied, action potentials

a. will not occur.
b. will start at that point and travel in all directions across the axon.
c. will start at that point and proceed only toward the axon terminal.
d. will start at that point and proceed only toward the cell body.