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A2 Edexcel Unit 5 Bio exam discussion (31 Jan 2012)

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Reply 60
Original post by ih8edexcel!
ur welc ! :smile: i hope you all get A* ! im not giving this unit !


Thank u!!!! :smile:
Reply 61
Original post by ih8edexcel!
ur welc ! :smile: i hope you all get A* ! im not giving this unit !


thx!!!!!!!!!!!! :biggrin:
Reply 62
hey can anyone maybe explain to me what they mean in paragraph 6 of the article on page 2? I get that the process kind of mimics lesioning but is that a good or a bad thing ? I guess good because it has the same effect as lesioning but is reversible?
Reply 63
Hi guys.

I have some questions here, hope to get some answers from you guys.

(para 1): What is blinded studies?
(para 3): "One of the 3 areas of brain" Which are them?
(para 6): "adenosine A1 receptor activation depresses excitatory transmission in the thalamus" I can't get what it means by this sentance.
(para 10): "do not respond to this dug" Why?

Also, it may be helpful to outline some points about:

Why DBS is still not common?
Why DBS has less effect on depression compared with other diseases mentioned in article?
Ethics of animal models and human trials.


By the way, I have noted some italic words in the article:
para 10: levadopa
para 11: pedunculopontine nucleus
para 49: final common pathway
para 51: basal ganglia & thalamus
I personally think there must been something to do to highlight those words.

All the best to all students taking the paper!
Reply 64
no it is not good bec. the DBS caused the release of ATP which resulted in the formation and release of inhb.neurotransmitters, so when they took a slice from the thalamus of the mice they found a lesion in the thalamus which means that part of the thalamus got damaged...... well that is what my teacher told me ....
gd luck :wink:
Original post by Laraaa
hey can anyone maybe explain to me what they mean in paragraph 6 of the article on page 2? I get that the process kind of mimics lesioning but is that a good or a bad thing ? I guess good because it has the same effect as lesioning but is reversible?
Reply 65
Original post by ghogho
no it is not good bec. the DBS caused the release of ATP which resulted in the formation and release of inhb.neurotransmitters, so when they took a slice from the thalamus of the mice they found a lesion in the thalamus which means that part of the thalamus got damaged...... well that is what my teacher told me ....
gd luck :wink:


oh okay :s
thaanks nd good luck to u too :smile:
Reply 66
Original post by Danniel
Hi guys.

I have some questions here, hope to get some answers from you guys.

(para 1): What is blinded studies?
This is when the patient does not know whether the electrodes have been implanted or whether the impulses have been switched on. It allows the doctor to measure the psychological effect of DBS.
(para 3): "One of the 3 areas of brain" Which are them?
The three areas are the Cerebrum which is associated with the mental activity of brain like language, memory ect and controlling of voluntary activities. Second is Cerebellum which is movement and balance and third is Medulla Oblongata which controls heart rate, breathing ect. I assume they are implanted in cerebellum??
(para 6): "adenosine A1 receptor activation depresses excitatory transmission in the thalamus" I can't get what it means by this sentance.
:s-smilie: This confuses me too, but I think it means that the once the receptor is activated it prevents an action potential from occuring the in post synaptic membrane, and so the inhibitory effects results in what seems to be the destruction of brain tissue. I think the receptor releases neurotransmitters which bind to the receptor on the post synaptic membrane, therefore blocking and preventing other receptor neurotransmitters from binding. But im not really sure:frown:
(para 10): "do not respond to this dug" Why?
The drug doesn't convert to Dopamine in the brain, or converts in the blood instead which means it cannot get into the brain.

Also, it may be helpful to outline some points about:

Why DBS is still not common?
The full mechanisms are still unknown and hasn't been tested on enough people to show exactly the potential side effects. So there isnt enough evidence that DBS is effective and better than the standard treatment available.
Why DBS has less effect on depression compared with other diseases mentioned in article?
The site in the brain which is linked to depression is still be located, there are only theories on which areas cause depression:confused: This question is hard!
Ethics of animal models and human trials.

The use of animals is wrong, as it could seriously damage the animals health or result in death (Absolutelist view). But potential benefits seen can outweigh the harms (for both animal models and human trials.

By the way, I have noted some italic words in the article:
para 10: levadopa
para 11: pedunculopontine nucleus
para 49: final common pathway Anyone know what this would be?
para 51: basal ganglia & thalamus


All the best to all students taking the paper!


Thanks for the questions, really getting scared for the exam now! Any ideas on topics people? I'm thinking they talked about plant sensitivity in last two papers, so maybe talk about eyes?
Reply 67
i trulllley need hellllp!!!!!!!!!!!!!!!!!!!
plz can any one explain for me Q. 3 A) i) !!!!!!!!!! i truely cnt get it and i didnt understand da MS
i so dam nervous :s-smilie: :frown: ;(
Reply 68
Original post by G.Kaur

Original post by G.Kaur
Thanks for the questions, really getting scared for the exam now! Any ideas on topics people? I'm thinking they talked about plant sensitivity in last two papers, so maybe talk about eyes?


i think that they will ask about development in modern genetics , brain & learning , eye & i feel that there will be an ECG q...
brrr... im too nervous & v scareeeed :s-smilie: :s-smilie:
gd luch 4 all of us.............................
Reply 69
Original post by ghogho
i trulllley need hellllp!!!!!!!!!!!!!!!!!!!
plz can any one explain for me Q. 3 A) i) !!!!!!!!!! i truely cnt get it and i didnt understand da MS
i so dam nervous :s-smilie: :frown: ;(


what paper is it?
Reply 70
Original post by G.Kaur

Original post by G.Kaur
what paper is it?


may/ june 2011 ....
& thx in advance :smile:
(edited 12 years ago)
Reply 71
Original post by ghogho
may/ june 2011....
& thx in advance :smile:


So breathing rate is the volume of air breathed per minute or second or whatever, and each peak on a spirometer represents a breath. To find the breathing rate you count the number of peaks for a given amount of time, ie there may be 7 breaths in 15 secs so the breathing rate is 28 breaths per min (7 x 4 is 28).
The tidal volume is calculating by measuring the height of the peak from top to bottom.
Does this make sense?
Reply 72
Original post by G.Kaur

Original post by G.Kaur
So breathing rate is the volume of air breathed per minute or second or whatever, and each peak on a spirometer represents a breath. To find the breathing rate you count the number of peaks for a given amount of time, ie there may be 7 breaths in 15 secs so the breathing rate is 28 breaths per min (7 x 4 is 28).
The tidal volume is calculating by measuring the height of the peak from top to bottom.
Does this make sense?


i truely dnt knw h to thx u really thx alot :biggrin:
thats great i got it nw.
u helped me calm down a little bit thx u :smile:

so h is revsion going on with u ?
Reply 73
Original post by ghogho
i truely dnt knw h to thx u really thx alot :biggrin:
thats great i got it nw.
u helped me calm down a little bit thx u :smile:

so h is revsion going on with u ?


I'm glad to help :smile: I guess its okay, just worried about scientific article, what with it being worth 30% :frown: And I hope I dont mess up on timing with the exam, I always run out of time!

How about you?
I guess this will be me in may/June :redface:
Just had my first lesson in unit 5 :teehee:
Is it really hard guys?

Good luck tomorrow! :biggrin:
Reply 75
Original post by G.Kaur
I'm glad to help :smile: I guess its okay, just worried about scientific article, what with it being worth 30% :frown: And I hope I dont mess up on timing with the exam, I always run out of time!

How about you?


im also worried about the article but i got a good view about the dbs treating parkinson through watching a vedio on this web. http://www.edheads.org/activities/br...on/index.shtml i advice u to watch it it will def. help! i also think that they will ask us detailed qu about parkinson and depression...
well ryt nw im revising the past papers then will take a final look on my notes and finally end up by reading the article and the realted question....

tom is my last exam in this session h about u ?
Reply 76
Original post by This Honest
I guess this will be me in may/June :redface:
Just had my first lesson in unit 5 :teehee:
Is it really hard guys?

Good luck tomorrow! :biggrin:


hahahah gd luck :wink:
it is not that hard i think it is pretty enjoyable if u like human biology :smile:
Original post by ghogho
hahahah gd luck :wink:
it is not that hard i think it is pretty enjoyable if u like human biology :smile:


Yup, I like human biology a lot so that's good :thumbsup:
In the paragraph about Cerebral Palsy can someone tell me why DBS only targets dystonia and not *******ity? *******ity is the tightness of the muscle so shouldnt an action potential clear this up and trigger muscle movement?
Reply 79
Original post by Ayostunner
In the paragraph about Cerebral Palsy can someone tell me why DBS only targets dystonia and not *******ity? *******ity is the tightness of the muscle so shouldnt an action potential clear this up and trigger muscle movement?


first u have to note that the mechanism of action of the dps is still not well known! second i think it depend on the position in the brain where the dps cause action and the level of elctricity caused by the battery ( i mean the voltage)
and finally my advice to u dnt complicate life the questions will not be indepth about things that we didnt actully studied it in details and conc. on parkinson and depression as we have alot of detailed inf about them in the syll.

gd luck :smile:

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