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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[dentdoc10]

What is key charac about mand 1st molar? Mesiolingual developmental groove
Mand 1st M - 2 buccal grooves-MB, DB
Largest MD dia than any other tooth
Most often restored, extracted or replaced
ML dev groove- Mand 1st PM

this isnt right because isnt that the key characteristic of max first molar and premolar?
Max 1st M - DL dev groove
Max 1st PM - Mesial marginal dev groove

Cortical plate histologically has: I don't remember, one answer was Whorling bone
Haversian canals
Whorling bone pattern- seen in Nonossifying Fibroma (fibrous cortical defect)

blood supply of condyle? Br. of ECA
Mainly Superficial temporal art
Max art(Deep Auticular,Anterior Tympanic, Deep Temporal )
Ascending Pharyngeal art

fumarate is in what two pathways
Krebs cycle and Urea cycle

which of the following when metabolized is largest drop in free energy? Creatine phosphate, glucose 6 phosphate i think its this
Creatine Phosphate
(generally, P ester formed by splitting out H20 b/w phosphoric acid and hydroxyl group like in G6P, have low but -ve delta G of hydrolysis. Creatine phosphate has a methy group)

Just added a few extra points....hope it helps.
And great going Anaita..

 

[buntydr83]

it's june

 

[Anaita]

Pure rotation of the mandible involves which two planes of movement?
Frontal
Horizontal
Saggital

The correct answer per Decks is Frontal and Sagittal.

Can somebody explain the answer including why horizontal is not right?
Thanks

Pure rotation of mandible in isolation is physiologically possible only about the horizontal axis... reference Okeson Page 74.. correct me if i'm wrong

 

[Anaita]

[/COLOR]

Just added a few extra points....hope it helps.
And great going Anaita..

Thnx..
An example of primary active transport is movement of
a. glucose into muscle
b. potassium into nerve cell
c. Na into endothelial cell
d.oxygen across alveolar wall

 

[Anaita]

Thnx..
An example of primary active transport is movement of
a. glucose into muscle
b. potassium into nerve cell
c. Na into endothelial cell
d.oxygen across alveolar wall

Transmission of impulses from the motor nerve to the muscle cell regularly produces
a) an action potential in muscle
b) a graded potential in muscle cell
c) hyperpolarisation of muscle cell
d)hypopolarisation of muscle cell
e) alteration in threshold potential of muscle cell
Plz explain

 

[MPHer83]

Thnx..
An example of primary active transport is movement of
a. glucose into muscle
b. potassium into nerve cell
c. Na into endothelial cell
d.oxygen across alveolar wall

It can't be glucose because glucose is transported by GLUT 4 into muscle. It can't be Oxygen because it is transported via simple diffusion. So it's either b or c. But the best example of primary active transport is the Na/K pump in action potential where Na enters the cell and K exits the cell (not enter as in answer b). So the correct answer is (c) Na into endothelial cell.

Please correct me if I am wrong. My exam is in 9 days!

 

[MPHer83]

Transmission of impulses from the motor nerve to the muscle cell regularly produces
a) an action potential in muscle
b) a graded potential in muscle cell
c) hyperpolarisation of muscle cell
d)hypopolarisation of muscle cell
e) alteration in threshold potential of muscle cell
Plz explain

answer is a) action potential.But please correct me if I a m wrong. No time left. 9 days!

 

[doc76]

It can't be glucose because glucose is transported by GLUT 4 into muscle. It can't be Oxygen because it is transported via simple diffusion. So it's either b or c. But the best example of primary active transport is the Na/K pump in action potential where Na enters the cell and K exits the cell (not enter as in answer b). So the correct answer is (c) Na into endothelial cell.

Please correct me if I am wrong. My exam is in 9 days!

I think its potassium going into the nerve cell.coz Na -k ATP ase pump transport k ion from extracellular fluid into intercellular fluid and transport Na ion from intracellular to extracellular fluid. perfect example of primary active transport.
other examples are ca ion pump and proton pump in gastric parietal cell

 

[doc76]

answer is a) action potential.But please correct me if I a m wrong. No time left. 9 days!

I also think that the answer should be A

 

[doc76]

1

 

[buntydr83]

It can't be glucose because glucose is transported by GLUT 4 into muscle. It can't be Oxygen because it is transported via simple diffusion. So it's either b or c. But the best example of primary active transport is the Na/K pump in action potential where Na enters the cell and K exits the cell (not enter as in answer b). So the correct answer is (c) Na into endothelial cell.

Please correct me if I am wrong. My exam is in 9 days!

it should be potessium enter the cell
because active transport require for transport up the concentraction gradient.........

 

[buntydr83]

answer is a) action potential.But please correct me if I a m wrong. No time left. 9 days!

it's GREADED POTENTIAL,.........just type in wikipedia and u will find.........confirmed.....

 

[faddawe]

Originally Posted by efficient
Pure rotation of the mandible involves which two planes of movement?
Frontal
Horizontal
Saggital

The correct answer per Decks is Frontal and Sagittal.

Can somebody explain the answer including why horizontal is not right?
Thanks

what they mean here is that there are 3 shapes of movement diagram(poessel envelop of motion)and the rotation of the mandible is expressed only in the frontal and the saggital plane ,if you have any other opinion let me know

 

[faddawe]

Thanks.

The ability to concentrate urine varies among animal species. The max urine conc that can be produced by an animal is MOST closely relate to which of the foll:
a. renal blood flow
b. total number of nephrons
c. gfr
d. length of loop of henle
e. diameter of distal tubule

i will give you the answer and the clue .there are types of nephrons as you know 1-cortical nephrons (short loop of henly) 2-juxtramudullary nephrons (long loop of henly) and the function of the 2nd one is the concentration of urine due to its long loop so the answer is the length of the loop

 

[sw4gger]

Should be glucose 6 phosphate.. not sure

Creatine Phosphate has more energy

 

[sweetsmile1]

Q - Each of the following is attributable to hepatic failure except one. Which one is this exception ?
A-tremor
B-gynaecomastia
C-mallory bodies
D-hypoalbuminaemia
E-spider telangectasia

Answer is mallory bodies

Can anyone plz explain?

 

[Being human]

i think all the above conditions are involved with liver failure in general but mallory bodies is for alcoholic liver disease only..its not clear for me too...lets see what others have to say??

 

[Hatico]

Pure rotation of the mandible involves which two planes of movement?
Frontal
Horizontal
Saggital

The correct answer per Decks is Frontal and Sagittal.

This is geometrical Q.
Sagittal view: pure rotation is almost vertical poor curve 20 mm
Frontal: 20 mm line
Horizontal: dot to very short line - almost indistinguished

Base: vertical line is dot from horizontal view.

 

[Peter Ausman]

I just did the NDB step 1 and this was not my first attempt. Last time, which was last year, raw score was 233 (out of 400), which gave me 74. I honestly don't think I will answer much more than 233. Does anybody knows if this "scale" has changed since April 2010 last year? I mean for 13 months, are students making better where you need to answer for example 250 questions right to get the passing score of 75?
Last time I received the score report in about 13 days or so.. I hope this has not changed this year
Thank you guys

 

[restart1970]

Hi anyone appearing for Part 1 in dec?

 

[restart1970]

Anyone in Louisiana preparing for Part 1?pl respond.im confused.

 

[dentdoc10]

Q - Each of the following is attributable to hepatic failure except one. Which one is this exception ?
A-tremor
B-gynaecomastia
C-mallory bodies
D-hypoalbuminaemia
E-spider telangectasia

Answer is mallory bodies

Can anyone plz explain?

Mallory bodies are present in-
Alcoholic hepatitis
Alcoholic liver disease caused by alcoholic hepatitis
Wilsons desease
Hepatocellular carcinoma
Primary biliary cirrhosis

These conditions may/will lead to hepatic failure (showing mallory bodies) but liver failure by itself doesnt have mallory bodies.

 

[babinsky]

Hey guys.. new to the forum...!!

 

[babinsky]

Hey guys.. new to the forum...!![/QUOT
Could someone plz help me with this one
What is the commonest complication of peptic ulcer disease that accounts for majority of deaths
1, Bleeding
2 perforation
3 obstruction
4 malignancy
Thnx in advance

 

[DrHouseDDS]

Hey guys.. new to the forum...!![/QUOT
Could someone plz help me with this one
What is the commonest complication of peptic ulcer disease that accounts for majority of deaths
1, Bleeding
2 perforation
3 obstruction
4 malignancy
Thnx in advance

In the Decks it says it's hemorrhage. Anybody?
Also what about this one:
If the patient is edentulous, which artery won't be present?? Any ideas?

 

[buntydr83]

In the Decks it says it's hemorrhage. Anybody?
Also what about this one:
If the patient is edentulous, which artery won't be present?? Any ideas?

abt 1st que
if they are asking abt most common complication than ans is HEMORRAGE.
if they are asking abt most common complication that can led to death than ans ahould be PERFORATION....

is there any option in 2nd que ?

 

[Anaita]

In right lateral excursion max right first molar mesiofacial cusp passes through which of following grooves of mandibular first molar..
marked answer .. lingual groove.. my answer mesiofacial groove..



Which of following represents depth of curvature on tooth #13
> than mesial surface of # 6
< than mesial surface of tooth # 11
same as on msial surface of #6
same as on mesial surface of # 11
> mesial surface of tooth #5

Which of the following morphologic variations would worsen the prognosis for existing periodontal disease?
Fused roots
excessively long roots
shoveling trait in incisors
amelogenesis imperfecta

Each of the following molecules is paired with its precursors except one
1 Sucrose-Dextran
2 Glucose-glycogen
3 Sucrose-mutan
4 UDP glucose-glycogen
Sucrose-levan... i think this one is it.. but marked correct answer is choice 2

 

[faddawe]

abt 1st que
if they are asking abt most common complication than ans is HEMORRAGE.
if they are asking abt most common complication that can led to death than ans ahould be PERFORATION....

is there any option in 2nd que ?

for the artery that willbe absent in edentulous patient ,yu can choose one of 3 which will be in the answer choices
1- interalveolar arterioles
2- periodontal ligament arteriole
3-dental arteriole

 

[faddawe]

In right lateral excursion max right first molar mesiofacial cusp passes through which of following grooves of mandibular first molar..
marked answer .. lingual groove.. my answer mesiofacial groove..



Which of following represents depth of curvature on tooth #13
> than mesial surface of # 6
< than mesial surface of tooth # 11
same as on msial surface of #6
same as on mesial surface of # 11
> mesial surface of tooth #5

Which of the following morphologic variations would worsen the prognosis for existing periodontal disease?
Fused roots
excessively long roots
shoveling trait in incisors
amelogenesis imperfecta

Each of the following molecules is paired with its precursors except one
1 Sucrose-Dextran
2 Glucose-glycogen
3 Sucrose-mutan
4 UDP glucose-glycogen
Sucrose-levan... i think this one is it.. but marked correct answer is choice 2

Which of following represents depth of curvature on tooth #13???????????? i cant get the question can you explain more if you mean the curvatur of cej proximally so no#2 will be the choice


Fused roots worsen the prognosis for existing periodontal disease

 

[Anaita]

Which of following represents depth of curvature on tooth #13???????????? i cant get the question can you explain more if you mean the curvatur of cej proximally so no#2 will be the choice


Fused roots worsen the prognosis for existing periodontal disease

Depth of curvature of cervical line on mesial surface....

 

[Anaita]

Which of following represents depth of curvature on tooth #13???????????? i cant get the question can you explain more if you mean the curvatur of cej proximally so no#2 will be the choice


Fused roots worsen the prognosis for existing periodontal disease

.. thnx.. should have read the question.. it says preexisting periodontal disease
Sucrose---> glucose +fructose
fructose---> levans.. so probably leaves us with only Glucose-- glycogen choice

 

[Anaita]

Which of the following explains why digestive action of salivary amylase continues for sometime after swallowing??
1. Gastric HCl increases the action of Amylase (Lippincott says Gastric HCl inhibits action of salivary amylase)
2. Gastric mucus lubricates the bolus and assists the amylase activity
3. Water absorption concentrates the amylase and makes its action more effective
4. Contractions of stomach distribute the amylase more evenlythrough out the bolus

 

[Anaita]

it should be potessium enter the cell
because active transport require for transport up the concentraction gradient.........

 

[Anaita]

Originally Posted by efficient
Pure rotation of the mandible involves which two planes of movement?
Frontal
Horizontal
Saggital

The correct answer per Decks is Frontal and Sagittal.

Can somebody explain the answer including why horizontal is not right?
Thanks

what they mean here is that there are 3 shapes of movement diagram(poessel envelop of motion)and the rotation of the mandible is expressed only in the frontal and the saggital plane ,if you have any other opinion let me know[/QUOT

When the mandible rotates it opens the jaw; so it moves in two planes.. 1) frontal... ie up and down.. but when the rotation takes place the mandible is also moving along an arc.. 2) anteroposteriorly ie in the sagittal plane but it does not move transversely or side to side in the horizontal plane (as in lateral excursions).. hope this helps.. am sure u must hv already got the answer by nw

 

[Anaita]

Originally Posted by efficient
Pure rotation of the mandible involves which two planes of movement?
Frontal
Horizontal
Saggital

The correct answer per Decks is Frontal and Sagittal.

Can somebody explain the answer including why horizontal is not right?
Thanks

what they mean here is that there are 3 shapes of movement diagram(poessel envelop of motion)and the rotation of the mandible is expressed only in the frontal and the saggital plane ,if you have any other opinion let me know[/QUOT

When the mandible rotates it opens the jaw; so it moves in two planes.. 1) frontal... ie up and down.. but when the rotation takes place the mandible is also moving along an arc.. 2) anteroposteriorly ie in the sagittal plane but it does not move transversely or side to side in the horizontal plane (as in lateral excursions).. hope this helps.. am sure u must hv already got the answer by nw

Infact with the change of present accepted dfinition of centric relation the earlier referred to as centric relation position in the Posselt's envelope is nw referred to as retruded contact position.. plz correct me if i'm wrong

 

[faddawe]

Infact with the change of present accepted dfinition of centric relation the earlier referred to as centric relation position in the Posselt's envelope is nw referred to as retruded contact position.. plz correct me if i'm wrong

yes absolutely true because CR and retruded contact position are the same in they are both the most posterior position for the mandible and no need to remind you that in 90% of people CR is 2 mm posterior than Centric occlusion

 

[GOLF82]

In the Decks it says it's hemorrhage. Anybody?
Also what about this one:
If the patient is edentulous, which artery won't be present?? Any ideas?

I think the dental arteriol since the teeth are missing and the answer for the stomach is bleeding . One of the late complication of peptic ulcer is perforation .

 

[GOLF82]

Any one can help me to find the correct answer for this question.

Methylxanthines such as caffeine or Theophylline enhance the lipolysis in adipose tissue by:
1. Inducing adenylate cyclase synthesis
2. Inducing Trigleceride lipase sytheseis
3. Inhibiting cyclic AMP
4.directly activating intracellular protein kinase
5.Enhancing binding epinephrine to extracellular membrane receptor

 

[Anaita]

Any one can help me to find the correct answer for this question.

Methylxanthines such as caffeine or Theophylline enhance the lipolysis in adipose tissue by:
1. Inducing adenylate cyclase synthesis
2. Inducing Trigleceride lipase sytheseis
3. Inhibiting cyclic AMP
4.directly activating intracellular protein kinase
5.Enhancing binding epinephrine to extracellular membrane receptor

Methyl xanthines are both adenosine inhibitors as well as phosphodiesterase inhibitors... thus prventing the breakdown of cyclis AMP and causing accumulation of intracellular cAMP levels

 

[Anaita]

yes absolutely true because CR and retruded contact position are the same in they are both the most posterior position for the mandible and no need to remind you that in 90% of people CR is 2 mm posterior than Centric occlusion

ICP is 2mm anterior to the RCP (retruded contact position).. the ICP may coincide with the CR or be distal to it...

 

[GOLF82]

Methyl xanthines are both adenosine inhibitors as well as phosphodiesterase inhibitors... thus prventing the breakdown of cyclis AMP and causing accumulation of intracellular cAMP levels

Thanks for the reply. Then how adenylate cyclase &/or cAMP increase the lipolysis ???. I am thinking about the effect on hormone sensitive lipase HSL ( I am not sure).

What about the protein kinase since the availability of cAMP activates protein kinase A specifically. I did found some connections between Protein kinase A and lipolytic pathway.

 

[McVinnie]

Which papilla is responsible for the umami taste?

 

[buntydr83]

Which papilla is responsible for the umami taste?

go through this......it present on every where on tongue where u can find taste receptor....


Taste receptors
All taste buds on the tongue and other regions of the mouth can detect umami taste independently of their location. The tongue map in which different tastes are distributed in different regions of the tongue is a common misconception. Biochemical studies have identified the taste receptors responsible for the sense of umami, a modified form of mGluR4, mGluR1 and taste receptor type 1 (T1R1 + T1R3), and all have been found in taste buds from any region of tongue.[27][28][29] The New York Academy of Sciences corroborated the acceptance of these receptors stating that "Recent molecular biological studies have now identified strong candidates for umami receptors, including the heterodimer T1R1/T1R3, and truncated tye 1 and 4 metabotropic glutamate receptors missing most of the N-terminal extracellular domain (taste-mGluR4 and truncated-mGluR1) and brain-mGluR4."[9]Receptors mGluR1 and mGluR4 are specific to glutamate whereas T1R1 + T1R3 are responsible for the synergism already described by Akira Kuninaka in 1957. However, the specific role of each type of receptor in taste bud cells remains unclear. They are G protein-coupled receptors (GPCRs) with similar signaling molecules that include G proteins beta-gamma, PLCb2 and PI3-mediated release of calcium (Ca2+) from intracellular stores.[30] Ca2+ activates the selective cation channel transient receptor potential melastatin 5 (TrpM5) that leads to membrane depolarization and the consequent release of ATP and secretion of neurotransmitters including serotonin.[31][32][33][34] Cells responding to umami taste stimuli do not possess typical synapses, but ATP conveys taste signals to gustatory nerves and in turn to the brain that interprets and identifies the taste quality.[35][36]

 

[buntydr83]

In right lateral excursion max right first molar mesiofacial cusp passes through which of following grooves of mandibular first molar..
marked answer .. lingual groove.. my answer mesiofacial groove..



Which of following represents depth of curvature on tooth #13
> than mesial surface of # 6
< than mesial surface of tooth # 11 - answer
same as on msial surface of #6
same as on mesial surface of # 11
> mesial surface of tooth #5

Which of the following morphologic variations would worsen the prognosis for existing periodontal disease?
Fused roots -answer
excessively long roots
shoveling trait in incisors
amelogenesis imperfecta

Each of the following molecules is paired with its precursors except one
1 Sucrose-Dextran
2 Glucose-glycogen- answer
3 Sucrose-mutan
4 UDP glucose-glycogen
Sucrose-levan... i think this one is it.. but marked correct answer is choice 2

about que 2


(1) Shovel Shaped Incisors
In incisors, the marginal ridges may be especially prominent and enclose a deep fossa in the lingual surface. There are a variety of systems for grading this trait. Dahlberg and others subsequently have devised cast plaster plaques for standardized study.
The shoveling is most common in permanent and deciduous upper incisors, but can at times appear in lower incisors also. At times, the shoveling can create a pit on the lingual surface of central incisors.

The highest frequencies (greater than 90%) are found amongst Asians and Native Americans and lowest amongst Europeans. Shovel shaped incisors appear in Homo erectus, suggesting that this is a very ancient trait.

so it can increase the risk of caries but not of periodontal disease


about last que
u r missing some thing they are asking
which of following is not correctly match with it's activated precursor
activated precursor for glycogen is udp-glucose not only glucose

 

[Anaita]

about que 2


(1) Shovel Shaped Incisors
In incisors, the marginal ridges may be especially prominent and enclose a deep fossa in the lingual surface. There are a variety of systems for grading this trait. Dahlberg and others subsequently have devised cast plaster plaques for standardized study.
The shoveling is most common in permanent and deciduous upper incisors, but can at times appear in lower incisors also. At times, the shoveling can create a pit on the lingual surface of central incisors.

The highest frequencies (greater than 90%) are found amongst Asians and Native Americans and lowest amongst Europeans. Shovel shaped incisors appear in Homo erectus, suggesting that this is a very ancient trait.

so it can increase the risk of caries but not of periodontal disease


about last que
u r missing some thing they are asking
which of following is not correctly match with it's activated precursor
activated precursor for glycogen is udp-glucose not only glucose

Thnx.. , will recheck the last question again...

 

[Anaita]

Thanks for the reply. Then how adenylate cyclase &/or cAMP increase the lipolysis ???. I am thinking about the effect on hormone sensitive lipase HSL ( I am not sure).

What about the protein kinase since the availability of cAMP activates protein kinase A specifically. I did found some connections between Protein kinase A and lipolytic pathway.

http://en.wikipedia.org/wiki/Lipolysis yeah.. you are right

 

[Anaita]

I think the dental arteriol since the teeth are missing and the answer for the stomach is bleeding . One of the late complication of peptic ulcer is perforation .

Thnx... plz do keep posting questions which you find difficult... exam in three weeks time

 

[Anaita]

Which of the following explains why digestive action of salivary amylase continues for sometime after swallowing??
1. Gastric HCl increases the action of Amylase (Lippincott says Gastric HCl inhibits action of salivary amylase)
2. Gastric mucus lubricates the bolus and assists the amylase activity
3. Water absorption concentrates the amylase and makes its action more effective
4. Contractions of stomach distribute the amylase more evenlythrough out the bolus

What about this one??

 

[GOLF82]

The salivary amylase works in the mouth Ph (around 7) which is it's optimum ph to achieve it's job. However, it will be denatured in the low ph ( around 2-3) in the stomach.

I think the last choice makes more sense than others

 

[GOLF82]

In the essential hypertension, which of the following represents the classic autopsy finding in the kidney?
1. Pyelonephritis
2. Glomerulonephritis
3. Benign nephroseclrosis
4.Renal artery stenosis
5.Renal carcinoma