Official NBDE Part 1 Study Q & A Thread

[tinman831]

Please post all study questions/answers for the NBDE Part 1 in this thread. Good luck!

As a side note, this is not the place for sales ads. Discussion of remembered questions appearing on the exam is also not permitted.

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[PooKan]

how hypothyroidism causes +ve nitrogen balance ....if there s hypo thn there will be decrease cellular metabolism and growth so -ve N2 balance right?
plz clarify this for me...thank u

 

[PooKan]

Is the question complete?
Either its 1 and 2 or just 3! If the collaterals are present then there wouldnt be infarction/fibrosis of myocardium(1 &2).
What was the answer Pookan?
Hatico....mind explaining your answer?

all 3 of them are right..this s the whole question:-
thrombotic occlusion of coronary artery may result in
a)infraction of myocardium
b)proliferation of myocardial fibers
c)fibrosis
d)stenosis of mitral valve
e)no changes in myocardium
1)a,b, or c
2)a,c, or d
3)a,c or e (ans)
4) b,d or e
5)any of the above

 

[Holly J]

all 3 of them are right..this s the whole question:-
thrombotic occlusion of coronary artery may result in
a)infraction of myocardium
b)proliferation of myocardial fibers
c)fibrosis
d)stenosis of mitral valve
e)no changes in myocardium
1)a,b, or c
2)a,c, or d
3)a,c or e (ans)
4) b,d or e
5)any of the above

That cant be!! can you tell me in which year's paper is this question? Let me check.

 

[PooKan]

That cant be!! can you tell me in which year's paper is this question? Let me check.

E series, Micro-path ,ques no- 64

 

[Hatico]

Hatico....mind explaining your answer?

Healthy heart almost has not collaterales between main vessels, but has reach small vessels collateral net. That is why total coronar artery occusion often does not lead to infarction. Few day after total occusion the blood circulit in the cardiac muscle is 50% of normal. In 25-30days - 100%.
Development of collaterales - main point in patients recovery after infarction ( if area of infarction is not too big).

There is cannot be proliferation also. Demaged muscle fibers are replaced by fibrous tissue.

 

[Holly J]

E series, Micro-path ,ques no- 64

Thanks Pookan ...I checked it...But still wouldnt agree with that option. If hatico is right then its just the last option.

Thanks Hatico for the explaination.

 

[Hatico]

. If hatico is right then its just the last option.
.

1. Coronal thrombosis - infarction - death
2. Coronal thrombosis - infarction - recovery by fibrosis
3. Coronal thrombosis - weak ischemia - 100% recovery
All options are correct.

 

[PooKan]

total number of cingula in each dentition is?
-6
-12(ans)
how can it be 12...they are asking total number in EACH dentition..it must be 6 right?

 

[Holly J]

total number of cingula in each dentition is?
-6
-12(ans)
how can it be 12...they are asking total number in EACH dentition..it must be 6 right?

It "dentition"(one set of teeth).....not quadrants!

 

[Hatico]

total number of cingula in each dentition is?
-6
-12(ans)
how can it be 12...they are asking total number in EACH dentition..it must be 6 right?

Dentition can be temporary and permanent, not upper and lower - correct?

 

[PooKan]

It "dentition"(one set of teeth).....not quadrants!

right. dentition means maxillary arch or mandi arch right...one set of teeth..

 

[Holly J]

Okay...human beings are called diphyodonts because they have two dentitions-deciduous and permanent(not upper /lower arch).

 

[PooKan]

Okay...human beings are called diphyodonts because they have two dentitions-deciduous and permanent(not upper /lower arch).

ohh understood ..had got the concept of dentition wrong...thankz Holly

 

[PooKan]

the term 'nephrosis' implies renal disease which primarily involves
-tubules( ans)
-glomeruli
-renal papillae
-renal artery
-interstitial CT
y cant it be glomerli...

 

[Hatico]

the term 'nephrosis' implies renal disease which primarily involves
-tubules( ans)
-glomeruli
-renal papillae
-renal artery
-interstitial CT
y cant it be glomerli...

Nephrosis is not inflammatory disease of renal tubules

 

[Hatico]

The largest incisal/occlusal embrasure is located between which of the following teeth?

1. Maxillary lateral incisor and canine
2. Maxillary canine and first premolar

 

[PooKan]

The largest incisal/occlusal embrasure is located between which of the following teeth?

1. Maxillary lateral incisor and canine
2. Maxillary canine and first premolar

its btw max LI and canine....

 

[Hatico]

In an acquired Class III crossbite relationship, as the mandible retrudes, the maxillary lateral incisor contacts which of the following teeth?

1. Central incisor
2. Lateral incisor
3. Central and lateral incisors
4. Canine and lateral incisors

Mandible is protuded in ClassIII occlusion, correct?

 

[Hatico]

its btw max LI and canine....

Yes, it is in ASDA-96, but canine&1P - in newer ASDA.

 

[PooKan]

In an acquired Class III crossbite relationship, as the mandible retrudes, the maxillary lateral incisor contacts which of the following teeth?

1. Central incisor
2. Lateral incisor
3. Central and lateral incisors
4. Canine and lateral incisors

Mandible is protuded in ClassIII occlusion, correct?

yes..mandible is protruded in Class III ....so when u retrude it as asked in question it will come to normal class I occlusion..so the ans will be mand canine and lateral incisor....

 

[PooKan]

an oral lesion tht may appear as an ulcer, a nodule or vegetative process and is often mistaken for squamous cell carcinoma is manifestation of
-candidiasis
-trichinosis
-sporotrichinosis
-histoplasmosis(ans)
i searched in wiki it have given no relevance to squamous cell carcinoma..i thought it resembles TB...is this option right?

 

[Holly J]

an oral lesion tht may appear as an ulcer, a nodule or vegetative process and is often mistaken for squamous cell carcinoma is manifestation of
-candidiasis
-trichinosis
-sporotrichinosis
-histoplasmosis(ans)
i searched in wiki it have given no relevance to squamous cell carcinoma..i thought it resembles TB...is this option right?

In simple terms the question is where do u see "ulcers/nodules"?
Its not seen in candida,trich,sporo....etc
O/M of Histoplasmosis:The lesions generally appear in the form of nodule. These nodules may be ulcerative or vegetative lesions. The common sites for oral histoplamic lesions are the buccal mucosa, gingiva, tongue, palate and lips.

 

[Holly J]

the term 'nephrosis' implies renal disease which primarily involves
-tubules( ans)
-glomeruli
-renal papillae
-renal artery
-interstitial CT
y cant it be glomerli...

Nephrosis affects only the epithelium of the tubules...glomeruli is not effected...and there is no inflamation related.

 

[Hatico]

What does it mean "facial view" - frontal or saggital?

 

[PooKan]

the most immediate source of oxaloacetic acid during metabolism is
- aspartic acid
but oxaloacetic acid forms aspartic acid right? and then its dumped into urea cycle!! plz correct me if iam wrong...

 

[PooKan]

What does it mean "facial view" - frontal or saggital?

frontal

 

[ionomer]

What does it mean "facial view" - frontal or saggital?

Also means labial view

 

[ionomer]

Thanks thats what i thought. They gave it as C. Anyways can you tell me difference b/w Idiotype, Isotype and Allotype in simple terms?

Idiotype - A set of one or more antigenic determinants specific to the variable region of an immunoglobulin molecule

Isotype - (1)A biological specimen that is a duplicate of a holotype (2) Any of the subclasses of immunoglobulins defined by the chemical and antigenic characteristics of their constant regions

Allotype - The protein product (or the result of its activity) of an allele which may be detected as an antigen in another member of the same species.(eg histocompatibility antigens, immunoglobulins), obeying the rules of simple Mendelian inheritance.

For a better picture of the three you can read this publication from this web addy - http://jeeves.mmg.uci.edu/Immunology/CoreNotes/Chap06.pdf

 

[PooKan]

what s diff btw resting lines and reversal lines?

 

[ionomer]

what s diff btw resting lines and reversal lines?

Resting lines - as seen in a histologic section of cortical bone of the mandible, are a result of growth of the mandible by appositional growth (2) Lines created by alternating periods of bone formation and rest, giving a tierlike appearance to lamellar bone

Reversal lines - Irregular lines containing concavities directed away from the bundle bone and serving as histologic indications that resorption has taken place up to that line from the marrow sidebone

 

[Hatico]

Also means labial view

Curve of Spee can be seeing from facial view. (ASDA papers)
I also though facial view is labial and frontal. But you can see posterior portion of curve from buccal (almost sagittal) view

 

[PooKan]

Resting lines - as seen in a histologic section of cortical bone of the mandible, are a result of growth of the mandible by appositional growth (2) Lines created by alternating periods of bone formation and rest, giving a tierlike appearance to lamellar bone

Reversal lines - Irregular lines containing concavities directed away from the bundle bone and serving as histologic indications that resorption has taken place up to that line from the marrow sidebone

 

[PooKan]

impulse conducting mechanism in heart is composed of
-autonomic nerve fibers
-modified cardiac muscle fibers(ans)
but impulse in heart is conducted by autonomic nervous system right? so in tht case option 1 must be right....and wht are these modified cardiac muscle fibers anyway

 

[Holly J]

impulse conducting mechanism in heart is composed of
-autonomic nerve fibers
-modified cardiac muscle fibers(ans)
but impulse in heart is conducted by autonomic nervous system right? so in tht case option 1 must be right....and wht are these modified cardiac muscle fibers anyway

It means the SA and AV nodes,bundle of His,purkinje fibres etc. Thats what conducts the impulse in heart..so right.

 

[PooKan]

skeletal muscle enlarges with prolonged activity as a consequence of
-differentiation of myoblasts
-mitotic division of muscle fibers
-increase in endomysial CT
-increase in sarcoplasm and in NUMBER of myofibrils of existing muscle fibers (ans)
how? skeletal muscle enlarges due to hypertrophy not hyperplasia right?

 

[Hatico]

skeletal muscle enlarges with prolonged activity as a consequence of
-differentiation of myoblasts
-mitotic division of muscle fibers
-increase in endomysial CT
-increase in sarcoplasm and in NUMBER of myofibrils of existing muscle fibers (ans)
how? skeletal muscle enlarges due to hypertrophy not hyperplasia right?

only hypertrophia. there is no hyperplasia

 

[PooKan]

only hypertrophia. there is no hyperplasia

ya i know...so how come this answer is right!!

 

[Hatico]

ya i know...so how come this answer is right!!

sorry, i missed it.
There are "myofibrils"(hypertrophia) in answers, not myocytes or myofibers(hyperplasia)

 

[PooKan]

sorry, i missed it.
There are "myofibrils"(hypertrophia) in answers, not myocytes or myofibers(hyperplasia)

i still did not understand...can u explain me again plz..thank u

 

[Hatico]

i still did not understand...can u explain me again plz..thank u

Myofiber is polinucleated "cell" that was developed from many mononucleated myocytes. Myofibrill is component of myofiber. Myofibril is organell in the cell.
Hypertrophia is increased size or number of organells (myofibrils in this case)
Hyperplasia - increased number of cells (myofibers).

 

[Holly J]

Myofiber is polinucleated "cell" that was developed from many mononucleated myocytes. Myofibrill is component of myofiber. Myofibril is organell in the cell.
Hypertrophia is increased size or number of organells (myofibrils in this case)
Hyperplasia - increased number of cells (myofibers).

Rightly said Hatico!

 

[PooKan]

Myofiber is polinucleated "cell" that was developed from many mononucleated myocytes. Myofibrill is component of myofiber. Myofibril is organell in the cell.
Hypertrophia is increased size or number of organells (myofibrils in this case)
Hyperplasia - increased number of cells (myofibers).

thank u

 

[PooKan]

if the spinal tract of 5th CN were to to sectioned at the level of caudal medulla , which of the foll would be most affected?
-taste
-proprioception
-pain from ipsilateral side of face(ans)
-light touch from contralteral saide of face
sensation s carried to contralateral side of brain right?

 

[Hatico]

if the spinal tract of 5th CN were to to sectioned at the level of caudal medulla , which of the foll would be most affected?
-taste
-proprioception
-pain from ipsilateral side of face(ans)
-light touch from contralteral saide of face
sensation s carried to contralateral side of brain right?

Caudal subnucleus (one of the spinal nuclei) transforms temperature and pain sensation, light touch - chief of pontine, proprioception - mesencephalis nucleus. So, answer is only "pain".
I cannot say anything about side of sensation, but rule about contralateral pain sensation is valid only for spinal nerves. There is different rule for cranial nerves. It depends on level of section - sometimes ipsilateral, sometimes contralatral loose of sensation.

 

[Hatico]

The non-working pathway of the maxillary cusps on the mandibular posterior teeth is toward the

1. distofacial.ans
2. distolingual.
3. mesiofacial.
4. mesiolingual.

it shoud be mesiolingual. Non- working pathway of the mandibular cusps on the maxillary posterior teeth is toward the distofacial, correct?

 

[Holly J]

The non-working pathway of the maxillary cusps on the mandibular posterior teeth is toward the

1. distofacial.ans
2. distolingual.
3. mesiofacial.
4. mesiolingual.

it shoud be mesiolingual. Non- working pathway of the mandibular cusps on the maxillary posterior teeth is toward the distofacial, correct?

Mesiolingual is the pathway of mandibular cusps....opposite direction for maxilla...therefore distofacial!

 

[Hatico]

Mesiolingual is the pathway of mandibular cusps....opposite direction for maxilla...therefore distofacial!

yeahhh! I found mistake. you are right

 

[PooKan]

in the embyro, ductus connects the
-rt atrium with lf atrium
-umbilical vein to inf venacava
-left pulmonary artery to aortic arch (ans)
-rt pul artery to aortic arch

now they havent mentioned if its ductus arteriosus or ductus venosus...so it can either be option 2( which s venosus) or option 3 (arteriosus) ....how do rule out btw them?

 

[ionomer]

in the embyro, ductus connects the
-rt atrium with lf atrium
-umbilical vein to inf venacava
-left pulmonary artery to aortic arch (ans)
-rt pul artery to aortic arch

now they havent mentioned if its ductus arteriosus or ductus venosus...so it can either be option 2( which s venosus) or option 3 (arteriosus) ....how do rule out btw them?

Yeah you are right i believe the question is incomplete or wrong.

 

[nbde2011]

1)The proper axial inclination of the maxillary cuspid?

2)When one presses the tongue tip against the anterior (incisor) teeth, which of the muscles must contract?