Let's try again, join me for study group NBDE I may/June 2010

[blissonearth]

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Hi friends, let's continue the closed thread here. No promoting any materials here, just prop some in doubt questions as our exam is approaching fast.

 

[Lord Voldemort]

i am now on verge i dont feel like studying anything.. 🙁 lol i feel my head has no more space in it...


hey lord velmont hows going on ur side?? though mine is bit late exam than urs.. i can imagine how u would be feeling.. 😛

i so wanna get over with it.....😴😴😴😴
although i m not feelin tensed...feels like any other exam....

 

[happyk9]

good luck 4 those who r taking exams shortly..................


ok, here is a question
1.soln A has ph 7 and B has ph 6,with both same volumes which statement below them is rt
ans 1.A has 1/10 as many h2 as B
2.A has 7/6 of h2 ion conc of B

I THUGHT OF ANS 1.by thinking A should hav less h2 than B as its ph is more than b
is there any eqation 2 calculate this...........

Answer: 1. A solution is neutral. B is more acidic, it has higher H+ concentration. The difference btw A and B: [A concentration]/[B concentration]=10 (-7 square)/10(-6 square)=1/10


2. wen masseter is activated by tapping which reflex is activate
sretch or withdrawal..........

stretch reflex. withdrawal reflex refers to when you suddenly bite a hard oject (like sand stone in your food), your jaws suddenly stop bitting and withdrawal. If I am wrong please let me know.

 

[aathmashree]

s,thats stretch reflex.

,an analysis of ekg shows p wave occuring in st segmant.this would indicate ectopic beat originating in

ans.atria
or lower bundle of his
.upper bundle of his


i thought atria, wat can u c in lower n upper bundle of his

stretch reflex. withdrawal reflex refers to when you suddenly bite a hard oject (like sand stone in your food), your jaws suddenly stop bitting and withdrawal. If I am wrong please let me know.

s

 

[happyk9]

s,thats stretch reflex.

,an analysis of ekg shows p wave occuring in st segmant.this would indicate ectopic beat originating in

ans.atria
or lower bundle of his
.upper bundle of his


i thought atria, wat can u c in lower n upper bundle of his










s

In normal condition, P wave stands for the depolarization of SA node and is ahead of QRS wave since SA node is the pace maker. QRS is the depolarization of ventricle and ST is the the full-depolarization of ventricle. If a p wave appears in the ST segment it usually means there is an ectopic beat happens before SA node depolarize. If this ectopic beat originates from lower bundle of his (which is in the wall between right and left ventricles), the P wave will appear after T wave (which is the repolarization of ventricle) or it will arrest in the next QRS wave (which you won't see p wave at all).

So i guess the answer should be upper bundle of his. Correct me if I am wrong.

Do you have the key for these questions?

By the way, could you please type the questions nicely so people won't have difficult to understand your questions next time? Thank you.

 

[teethie]

Hi, i think happyk9 has given a good logic.
aathmashree please confirm the answer if you have a key.
.

s,thats stretch reflex.

,an analysis of ekg shows p wave occuring in st segmant.this would indicate ectopic beat originating in

ans.atria
or lower bundle of his
.upper bundle of his


i thought atria, wat can u c in lower n upper bundle of his










s

 

[wdent]

hey i remeber seen this quest. before lot of limes ...
Answer :Lower bundle of His ...not sure though ! but ill rty to confirm as soon as i find the explanation!

 

[happyk9]

Thank you very much!

hey i remeber seen this quest. before lot of limes ...
Answer :Lower bundle of His ...not sure though ! but ill rty to confirm as soon as i find the explanation!

 

[dontist]

i so wanna get over with it.....😴😴
although i m not feelin tensed...feels like any other exam....

i dont know i am tensed.. 😱😱 since couple of days i am not more wrong answers in ASDA papers...

lol i m just thinking its better to fail royally than to pass poorly.. lollllll

 

[6789]

i have one random query..
when people say they score 85-90 in ASDA papers.. Does that mean they score that much for the first time they solve the paper??

I do not mean to offend anybody, I'm just curious.. And I think, if you are actually scoring that much for the first time you solve then paper.. then you are very well prepared.. And you will rock the exam !! Good luck !!

 

[wdent]

Hey Happyk9
I just couldnt get to a confirmation about the LOWER BUNDLE OF HIS as an answer ,,
r u really 100% sure with ur answer!!!! can u plsssssss confirm!
Teethie what do u think?

 

[happyk9]

Hey Happyk9
I just couldnt get to a confirmation about the LOWER BUNDLE OF HIS as an answer ,,
r u really 100% sure with ur answer!!!! can u plsssssss confirm!
Teethie what do u think?

I am not sure. After reading your repose to my previous answer, I have been thinking about the inferior bundle of his too. You may be right since there would be another QRS wave if the ectopic beat happens in superior of His bundle.

Since aathmashree is not giving us the key (or hasn't told us whether there is a key) for this question, I suggest that we move on. Don't waste too much time on this.

May be next time we should discuss the questions with AUTHENTIC keys. Say NO to crappily-typed questions.

 

[wdent]

ok !
thanks i will ... because ive seen that question before in one of the threads !! it got really confused that time..anyway thanks !(god bless ya )

 

[teethie]

Hi Guys,
I will keep this question in mind and sooner or later if I find an explanation, will post definitely, for now, my answer is Lower bundle of his.
we have to remember each question is important, and finding right key is more important. if the aathmashree posts the key, it will save our time.

ok !
thanks i will ... because ive seen that question before in one of the threads !! it got really confused that time..anyway thanks !(god bless ya )

 

[wdent]

hey guys,,i always had doubts about that question too , the answer is lower bundle of his,,some one on sdn long time ago explained it ,,but unfortunatly cant find the thread anymore !!! Aathmashree can u confirm it plsssss? thanks teethie in advance for help,,pls post it as soon as u get the explanation!

 

[happyk9]

Can anybody help me to answer two questions?

1. A woman in her second trimester took tetracycline what teeth of her baby would be affected?

2. If upper first premolar have 3 roots, where would they be?

 

[rooz]

Can anybody help me to answer two questions?

1. A woman in her second trimester took tetracycline what teeth of her baby would be affected?

2. If upper first premolar have 3 roots, where would they be?

Hi happk9 the first one :all primary teeth .
for Q2 I'm not sure but I think 2 buccal one palatal

 

[aathmashree]

sorry guys, 4 delay, i count check thread, but anyways no key 4 this question, i saw this question twice ,will quote the ans as soon as found,ekg is very imp, so got 2 know abt this








QUOTE=happyk9;9744016]I am not sure. After reading your repose to my previous answer, I have been thinking about the inferior bundle of his too. You may be right since there would be another QRS wave if the ectopic beat happens in superior of His bundle.

Since aathmashree is not giving us the key (or hasn't told us whether there is a key) for this question, I suggest that we move on. Don't waste too much time on this.

May be next time we should discuss the questions with AUTHENTIC keys. Say NO to crappily-typed questions.[/QUOTE]

 

[godblessus]

i so wanna get over with it.....😴😴😴😴
although i m not feelin tensed...feels like any other exam....

Hi, How was ur exam today? Mine was okay!! Just wannna know as u also gave same day.

 

[dontist]

\

can anyone explain why 5 is the answer?? i thought the answe is 4. max CI contacts md CI and LI in retrusive movement.


btw.. Lord Velmont how was the exam buddy?????

 

[dontist]

Hi, How was ur exam today? Mine was okay!! Just wannna know as u also gave same day.

any advises for last moment takers?? can u share ur overall experience??

were the questions twisted and more clinical oriented?? how about the level as compared to ASDA papers?? pl tell what u feel about the overall exam..🙂

thanks ... really appreciated.

 

[teethie]

hi, agree with rooz

Hi happk9 the first one :all primary teeth .
for Q2 I'm not sure but I think 2 buccal one palatal

 

[rose82]

pls help me with explanation (why the other answer is wrong?)

when fatty acid oxidation predominates in liver,mitochondrial pyruvate is most likely channelled to
1)acetyl COA for ketogenesis
2)oxaloacetate for gluconeogenesis

 

[dontist]

i have a small query.. when does the proameloblast changes to ameloblast??

after it comes in contact with dentin??
or after it comes in contact with odontoblast???

i think after the 1st layer of dentin is laid.. ameloblast are formed right?? so it should be the 1st option..

but ans is after it comes in contact with odontoblast... any explanations ???

pl help me out..

 

[rooz]

pls help me with explanation (why the other answer is wrong?)

when fatty acid oxidation predominates in liver,mitochondrial pyruvate is most likely channelled to
1)acetyl COA for ketogenesis
2)oxaloacetate for gluconeogenesis

I think No 2 is correct.when fatty acid oxidation is predominance ,we dont have enough carb(glucoes)to use so when glucose is not obtained in the diet the body must produce new one from noncarb precursor,so gluconeogenesis activated.

 

[aathmashree]

pls help me with explanation (why the other answer is wrong?)

when fatty acid oxidation predominates in liver,mitochondrial pyruvate is most likely channelled to
1)acetyl COA for ketogenesis
2)oxaloacetate for gluconeogenesis

ans.2.pyruvate formed from citrate shuttle in FA synthesis at cytosol,enters mitochondria n converted 2 oxaloacetate for krebs cycle

 

[godblessus]

any advises for last moment takers?? can u share ur overall experience??

were the questions twisted and more clinical oriented?? how about the level as compared to ASDA papers?? pl tell what u feel about the overall exam..🙂

thanks ... really appreciated.

\

Hi,
Finally done with the exam Yesterday...relieved..n feeling back to life!
Honestly compared to ASDA papers it was quite different, i felt as if only 1-2 % were repeated. Clinical oriented questions were easy and straight forward compared to the other questions. I don't want to discourage any of the future test takers as this is what i perceived. Lastly go through pathology especially high yield facts of all diseases. Overall exam was okay not bad, if u have ur basics cleared u can do well. Also concentrate more on the ADAs favorite topics like Nervous system, hormones, pathology and antibiotics very well for clinical cases. I made few mistakes of going back and changing the answer. Go with ur 6th sense or gut feeling but never ever change the answer. Also don't forget to do TMJ very very well!!!👍 Good luck everyone!!

 

[happyk9]

I think No 2 is correct.when fatty acid oxidation is predominance ,we dont have enough carb(glucoes)to use so when glucose is not obtained in the diet the body must produce new one from noncarb precursor,so gluconeogenesis activated.

I think the answer should be 2.

Under the normal condition (normal diet, non-fast, non-diabetes), the pyruvate is usually generated by glucose under glycolysis. When there is too much fatty acids oxidation (for example, fast-state), some glucogenic amino acids will generate pyruvate, these pyruvate then are transformed to oxaloacetate, then channel into gluconeogenesis.

This question is very tricky since it is asking the pyruvate, not the acetyl coA. If the question is asking the acetyl coA, the answer should be 1. Acetyl coA can not be tranformed back to pyruvate. Too much acety-coA turns into keton bodies.

 

[happyk9]

Hi happk9 the first one :all primary teeth .
for Q2 I'm not sure but I think 2 buccal one palatal

Thank you. I am thinking Q2 is 2 buccal and one palatal too. I think this makes sense: this weird tooth will have premolar crown and molar roots.

 

[dontist]

i think the answer is decrease in pO2 ...ans B

can any one confirm if C is the correct ans?? i mean the chemoreceptors are only activated and respond to decrease in oxygen.

 

[teethie]

Hidontist, respiration stimulus takes place only when there is increase in arterial pCO2. this will cause increase in hydrogen ion and this is now decreased ph of arterial blood thereby increasing respiration.

i think the answer is decrease in pO2 ...ans B

can any one confirm if C is the correct ans?? i mean the chemoreceptors are only activated and respond to decrease in oxygen.

 

[aathmashree]

Hidontist, respiration stimulus takes place only when there is increase in arterial pCO2. this will cause increase in hydrogen ion and this is now decreased ph of arterial blood thereby increasing respiration.

i thought central chemoreceptors[medulla] r stim by increase in,pco2,n increase in ventilation

periferal chemoreceptors[aortic n carotic boby] respond 2 both decrease in po2 n increase in pco2 n increases the ventilation....

is tht rt.........


2.pt with hyperparathyroidismcomplain of tmj pain n clogging,so which is most liekly increased in this pt/?
ans.1increased intestinal calcium absorption
2.renal caalcium excreation..

ans given as 2. why not 1.


3.oedema not found in pancreas why?

 

[dontist]

Hidontist, respiration stimulus takes place only when there is increase in arterial pCO2. this will cause increase in hydrogen ion and this is now decreased ph of arterial blood thereby increasing respiration.

as far as the wiki goes.. there are central and peropheral chemoreceptors which alter the respiration.

peripheral chemo receptors stimulated when there is low oxygen tension.

central chemoeceptors do not respond to oxygen or carbon dioxide in blood, instead they respond to the ph of CSF .. as carbon dioxide can freely pass thru BBB, when increase in carbon dioxide will result in decrease in ph of CSH which can be closely compared to blood pH. hence they get stimulated.

but i dont know is it like the main respiration is governed by central chemo and not peripheral chemo??

i feel peripheral chemo respond quickly as compared to peripheral.

if somehow anyone can justify the correct ans it wil be great.

 

[rose82]

Thanks everybody for the explanation.I had the doubt because when there is excess fatty acid oxidation,ketone bodies begin to form.There is a thin line which is bound to confuse you.Anyway,2 is the answer.

 

[dentist 2010]

Electonegativity in living cells requires that

1. a potential for charge separation exists
2. biologic water assumes a crystalline pattern at the membrane
3. negative charges outnumber positive charges within the cells cytoplasm
4.none of the above.

ans is 1. a potential for charge separation exists
can anybody explain?

 

[aathmashree]

c dna libraries are made up of
ans1.mrna sequences only
ans2 .entire dna genome......
plz explain.

 

[happyk9]

Electonegativity in living cells requires that

1. a potential for charge separation exists
2. biologic water assumes a crystalline pattern at the membrane
3. negative charges outnumber positive charges within the cells cytoplasm
4.none of the above.

ans is 1. a potential for charge separation exists
can anybody explain?

This question is basically asking you the concept of resting membrane potential. You can check your book and usually it explains it very well.

 

[happyk9]

c dna libraries are made up of
ans1.mrna sequences only
ans2 .entire dna genome......
plz explain.

cDNA is short term for complimentary DNA. It is the result of reverse transcription of mRNA done by reverse transcriptase. Such thing happens in viruses like HIV, or in the molecular cloning done in the research Lab.

Forgot to mention: cDNA library is the cDNA library for all the mRNA in the cell or tissue. Usually scientists extract mRNA from the cell or tissue and use reverse transcriptase to make complimentary DNA. Since there are many mRNA(s) in the cell or tissue, all the cDNA information (sequence) gather together can form a library called cDNA library.

Hope this helps.

 

[teethie]

Hi dontist and aathmashree,
you are right aatmashree but in choices, there is no option of chemoreceptors, so increase in ventilation is due to increase in co2.
dontist:
respiration stimulus is via central chemorceptors(medulla) as peripheral chemoreceptors will help regulation of blood pressure. and mechanism of activating central chemorceptors is via decreased ph.

as far as the wiki goes.. there are central and peropheral chemoreceptors which alter the respiration.

peripheral chemo receptors stimulated when there is low oxygen tension.

central chemoeceptors do not respond to oxygen or carbon dioxide in blood, instead they respond to the ph of CSF .. as carbon dioxide can freely pass thru BBB, when increase in carbon dioxide will result in decrease in ph of CSH which can be closely compared to blood pH. hence they get stimulated.

but i dont know is it like the main respiration is governed by central chemo and not peripheral chemo??

i feel peripheral chemo respond quickly as compared to peripheral.

if somehow anyone can justify the correct ans it wil be great.

 

[rose82]

This question is basically asking you the concept of resting membrane potential. You can check your book and usually it explains it very well.

where is it given?i mean which chapter is it related to?(if u can remember)

 

[happyk9]

where is it given?i mean which chapter is it related to?(if u can remember)

Usually it is in the nervous system. Or if you have much more complicated textbook for Physiology it is usually in cellular physiology section.

 

[DrGSP]

Originally Posted by dontist

Hi Teethi, Dontist and Aathmashree
Following is my understanding for the above question:
Ans is 'c' because:
CO2 alone can diffuse thr CSF---> decrease CSF pH and stimulate central chemoreceptor----->increase respiration.

Ans 'd' ruled out because:
Decrease in blood pH is due to increase in H+ which could be due to various reasons including increase in CO2. But H+ cannot diffuse thr CSF.
Hence cannot stimulate central chemoreceptors to increase respiration.

Decrease in blood ph will stimulate peripheral chemoreceptors to increase respiration. But Central stimulation is the main drive to increase respiration.

 

[wdent]

c dna libraries are made up of
1.mrna sequences only
2 .entire dna genome......
plz explain.

Hey Happy !
So ur Sayin that answer number 2.(entire dna genome) is the answer !!!

aathmashree since this questions is from u originally,,can u pls confirm the answer pls!!

 

[aathmashree]

where is it given?i mean which chapter is it related to?(if u can remember)

hey u can check this out in u tube ,explained well




tnz happy ,good explaintn 4 cdna

 

[aathmashree]

c dna libraries are made up of
1.mrna sequences only
2 .entire dna genome......
plz explain.

Hey Happy !
So ur Sayin that answer number 2.(entire dna genome) is the answer !!!

aathmashree since this questions is from u originally,,can u pls confirm the answer pls!!

ans as mrna,i guess happy meant the same 2

 

[dontist]

Originally Posted by dontist

Hi Teethi, Dontist and Aathmashree
Following is my understanding for the above question:
Ans is 'c' because:
CO2 alone can diffuse thr CSF---> decrease CSF pH and stimulate central chemoreceptor----->increase respiration.

Ans 'd' ruled out because:
Decrease in blood pH is due to increase in H+ which could be due to various reasons including increase in CO2. But H+ cannot diffuse thr CSF.
Hence cannot stimulate central chemoreceptors to increase respiration.

Decrease in blood ph will stimulate peripheral chemoreceptors to increase respiration. But Central stimulation is the main drive to increase respiration.

Hi dontist and aathmashree,
you are right aatmashree but in choices, there is no option of chemoreceptors, so increase in ventilation is due to increase in co2.
dontist:
respiration stimulus is via central chemorceptors(medulla) as peripheral chemoreceptors will help regulation of blood pressure. and mechanism of activating central chemorceptors is via decreased ph.

made sense ... it was good. thanks teethie for the reply...

guys which of the root may have 2 pulp canals??
mesiobuccal root of max 1st molar?
mesial root of mand 1st molar??

i think its both.. both have 2 pulp canals.. but the answer is mesial root of mandibular 1st molar.... any suggestions??


lingual height of contour of mandibular 2nd Pm???
middle third ??
occlusal third??

as far as given in decks, the lingual height of contour of all posterior teeth is in middle third. but here in this que ans is occlusal third...

 

[dontist]

isnt it fusion??? widely notched tooth???

 

[dontist]

hows dense in dente?? pl ppl share some explanation...

 

[teethie]

Hi dontist, remeber this rule if

If tooth is missing it is fusion, if it is not missing, it is gemination.in your question, radiographically 28 teeth are present so it is not missing any incisor.it is gemination.​

isnt it fusion??? widely notched tooth???

 

[doctorzeuss]

I got one for you:

The extracellular polysaccharides synthesized by cariogenic streptococci in the presence of excess sucrose are best described as:

a) Amylase.
b) Amylopectin
c) Mucopolysaccharide
d) glycogen-like glucan
e) dextran-like glucan

Says the right answer is amylase. Anybody knows why?😕

 

[teethie]

hi answer is in green.

c dna libraries are made up of

1.mrna sequences only-------------ans

2 .entire dna genome......
plz explain.

Hey Happy !
So ur Sayin that answer number 2.(entire dna genome) is the answer !!!

aathmashree since this questions is from u originally,,can u pls confirm the answer pls!!