Lets discuss questions of NBDE 1

[d dimps]

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1). .Which angle does a P Wave makes on ECG?
a). .45 degree
b). .180 degree
c). .0 degree
d). .-45 degree
e). .-180 degree.

2). .What is endogenous cholesterol? Most endogenous cholesterol is converted to?
a). .Glucose
b). .Cholic acid
c). .Steroid
d). .Oxaloacetete
e). .Ketone bodies

3). .Which of the following statement is correct regarding Glioblastoma multiforme?
a). .the tumor is most common before puberty
b). .it is classified as a type of meningioma
c). .it is most common type of Astrocytoma.
d). .Its prognosis is generally more favourablethan Grade 1 astrocytoma.
e). .It is derived from the epithelial lining of ventricles

4). .Which of the following pathological changes is irreversible?
a). .fatty changes in liver cells
b). .karyolysis in myocardial cells
c). .glycogen deposition in hepatocyte nuclei
d). .hydropic vacuolization of renal tubular epithelial cells.

5). .An example of Synergism is the effect of?
a). .insulin and glucagon on blood glucose
b). .estrogen and progesterone on uterine motility
c). .growth hormone and thyroxine on skeletal growth.
d). .Antidiuretic hormone and aldosterone on potassium excretion.

 

[Haam]

I guess the answer is B.

the mandibular teeth usually inclined lingually, there is a lingual inclination in the occlusal table of the mand 1st premolar , excluding answer C, which is very characterstic.

 

[Anaita]

Refer N series,
Q 24 Which Amino Acid possesses a hydrophobic side chain?
a Lysine
b Cysteine
c Leucine
d hydroxyproline
e glycine

my answer.... glycine and Leucine,
key answer is leucine... 😕

Q113
Gel Electrophoresis is used to separate molecules by
a shape
b charge
c viscosity
d mass & shape
e charge and size
My answer b... charge, key answer e... plz explain

 

[Anaita]

Kaplan lists Methionine in the a non charged polar R group AA while Lippincott lists methionine in the nonpolar ( hydrophobic) group of AA; plz do lemme know if you guys find something on that??

 

[Anaita]

👍

I guess the answer is B.

the mandibular teeth usually inclined lingually, there is a lingual inclination in the occlusal table of the mand 1st premolar , excluding answer C, which is very characterstic.

 

[teethie]

hi anaita, answer is leucine, it is confirmed. i remember, i have shared a link on this. you lok on google and you will find out that one of them is strongly hydrophobic and other is weakly hydrophobic, hence leucine is a confirmed and right answer.

Refer N series,
Q 24 Which Amino Acid possesses a hydrophobic side chain?
a Lysine
b Cysteine
c Leucine
d hydroxyproline
e glycine

my answer.... glycine and Leucine,
key answer is leucine... 😕

Q113
Gel Electrophoresis is used to separate molecules by
a shape
b charge
c viscosity
d mass & shape
e charge and size
My answer b... charge, key answer e... plz explain

 

[Anaita]

hi anaita, answer is leucine, it is confirmed. i remember, i have shared a link on this. you lok on google and you will find out that one of them is strongly hydrophobic and other is weakly hydrophobic, hence leucine is a confirmed and right answer.

Thanx teethie.. looks like evryone here's done with exams or they probably hv gone into hibernation... 🙂

 

[billys]

Acetlycholine is released in at all of the following junctions except

1.Sympathetic ganglia
2.Parasympathetic ganglia
3.Somatic efferents to skeletal muscles
4.terminal sympathetic fibers to the heart
5.terminal sympathetic fibers to the adrenal medulla

ans is 4.

all pre ganglionic and post ganglionic fib release Ach except for post gagnlionic sympathetic that release norepinephrine, except at sweat glands and skeletal muscle areterioles.

can anyone explain this.

would appreciate it.

 

[tissy]

What is an absolute contra-indication for the use of Nitrous Oxide?

Sickle cell anemia or COPD

 

[perfectionist1]

What is an absolute contra-indication for the use of Nitrous Oxide?

Sickle cell anemia or COPD

Its COPD...
http://books.google.com/books?id=lh...&resnum=1&ved=0CCwQ6AEwAA#v=onepage&q&f=false

 

[dentdoc10]

In position in the alveolar bone, the longitudinal axis of which of the following teeth is inclined toward the lingual?

• a. all posterior teeth
  b. all mandibular posterior teeth
  c. the mandibular second premolar and all mandibular molars d. all maxillary molars

ANS: all mandibular posterior teeth
with Mandibular 1st premolar with extreme lingual inclination of all posterior teeth

 

[dentdoc10]

Refer N series,
Q 24 Which Amino Acid possesses a hydrophobic side chain?
a Lysine
b Cysteine
c Leucine
d hydroxyproline
e glycine

my answer.... glycine and Leucine,
key answer is leucine... 😕

Q113
Gel Electrophoresis is used to separate molecules by
a shape
b charge
c viscosity
d mass & shape
e charge and size
My answer b... charge, key answer e... plz explain

ANS: e
Gel electrophoresis is a process in which molecules (such as proteins, DNA, or RNA fragments) can be separated according to size and electrical charge by applying an electric current to them while they are in a gel. The current forces the molecules through pores in a thin layer of gel, a firm jelly-like substance. The gel can be made so that its pores are just the right dimensions for separating molecules within a specific range of sizes and shapes. Smaller fragments usually travel further than large ones.

 

[billys]

hey there everybody,

I have got my exam in about a week, and as i keep solving asda, keep noticing errors in the key..

are there errors in it or is it just me..

ASDA I-H

Which of the following arteries is not derived from the celiac trunk or its branches,

a.Left gastric
b Short gastric
c Gastroduodenal
d. Left gastroepiploic
e. Inferior Pancreaticoduodenal

the key is given as d..

it should be e a branch of superior mesenteric,

are there errors in the asda keys?

or am i missing something. can someone explain?


ASDA - L

351.

Each of the following statements correctly describes similar characteristics of the chemical senses of taste and smell Except one.

a. receptor cells are replaced regularly
b. There are primary classes of taste and of odor
c.Receptor are located on microvilli at the apical ends of cells
d.receptors initiate action potentials directly to respective cranial nerve sensory fibers
e. molecules must be dissolved in saliva or mucous to interact with receptor membrane protiens

Key: d

I am thinking the answer should be a as olfactory epithelium IS THE ONLY area in the body where neuronal cells are repeatedly replaced.

And they do convey the AP to their cells dirctly, bipolar cells in case of olfactory epithelium

I would appreciate if someone could justify this answer.

 

[Holly J]

About the 2nd question,its asking "except one"?
so olfactory epithelium is replaced...n also taste receptors-every 10-15days.so thats eliminated!
1st questn...I think u r right about that...that must be a mistake in the ASDA.
Good luck with your exam.

 

[vkgbpl]

ASDA I-K 140

which of the following could be beneficial in reducing edema in the arms of women who have had radical mastectomy with removal of axial lymph nodes
a.hypertensive drugs
b.avoidance of all diuretic agents
c.increased interstitial oncotic pressure
d.decrease in interstitial hydrostatic pressure
e.administration of plasma volume expanders

ans is e..
kindly anybody expalin..
i was thinkin of option d..

 

[sailing]

I-C biochemistry question 61

The osmotic pressure of the filtrate at the end of the proximal convoluted tubule is
1. greater than that of plasma
2. much less than that of plasma
3. about the same as that of plasma
4. greate than that of the filtrate in the descending portion of the loop of henle.

the ans is 3

can't understand it, since the descending limb is still reabsorting water due to osmosis

 

[Holly J]

I-C biochemistry question 61

The osmotic pressure of the filtrate at the end of the proximal convoluted tubule is
1. greater than that of plasma
2. much less than that of plasma
3. about the same as that of plasma
4. greate than that of the filtrate in the descending portion of the loop of henle.

the ans is 3

can't understand it, since the descending limb is still reabsorting water due to osmosis

Yes, its almost the same.Its called Iso-osmotic reabsorption.
Read this:
http://www.acbrown.com/renal/OutProx.htm

 

[sailing]

thanks!

Yes, its almost the same.Its called Iso-osmotic reabsorption.
Read this:
http://www.acbrown.com/renal/OutProx.htm

 

[zappy]

are there questions in the exam that require calculations based on the verious formulae & equations in Physiology???

 

[buntydr83]

Which of the folloeing strucure pass through rather than posterior to diaphragm?
1. Aorta
2. Esophagus
3. Azygous vain
4. Thoracic duct

 

[Amreki]

only esophagus and inferior vena cava actually pass through the diaphragm. the rest are through the aortic hiatus which actually passes behind the diaphragm, so these structures aren't affected by diaphragm contractions. esophagus and inferior vena cava use the muscle contractions of the diaphragm to pump back venous return and as a sphincter.

so my answer would be esophagus.

in first aid nbde tho, it doesnt differentiate any of this. it just says ALL these structures pass through the diaphragm. any one else shed some light on this?

 

[buntydr83]

thanks amreki
that's why i was confuse...
esophagus is the right ans...

 

[buntydr83]

capillary diameter is directly influenced by
1. sympathetic n.impulse
2. parasympathetic n.impulse
3. byproduct of metabolism

given ans ic 3.byproduct of metabolism
why?

 

[Amreki]

hey bunty, i answered this in the other topic where you asked the question as well.. but i guess i'll repeat it here..

it can't be parasympathetic or sympathetic because they affect the smooth muscle in the vasculature. the capillaries consist only of a single lining of endothelium and no smooth muscle.

 

[buntydr83]

@ Amreki
thanks for explanation..
by the way when u r planning for exam?

 

[Amreki]

march 23rd!!! im freaked out! haha.. lets see what happens...

 

[dentex]

I have a question, so axons of sensory neuron of trigeminal ganglia enter cns nucleus? these nucleus has motor connections?

i was wondering other than trigeminal nucleus which has cellbody, axon and dentrites, it is also conected to nuclues of the brain which has cellbody ,dendrite and axon.

i am just starting,can anyone help

 

[preOMFS]

1......diminished parotid salivation due to middle ear involvement...nerve mostly involved...ans lesser petrosal....y not auriculo temporal as it also supplies parotid
2..sensation of clogged ears is due to pressure on auditory tubes......nerve providing this sensory innervetion is......glossopharyngeal nerve....y not vestibulocochlear
3)female with bilateral pain in TMJ,ears clogged ringing sensation,..region of articular surface of TMJ not present...ans is proliferative zone

1. Auriculotemporal nerve is purely sensory, lesser petrosal travels with it on its way to parasympathetic innervation to the parotid gland.

2. CN VIII is a special sensory nerve, i.e. no cutaneous innervation.

3. Not sure what the question is here.

 

[dentex]

1. Auriculotemporal nerve is purely sensory, lesser petrosal travels with it on its way to parasympathetic innervation to the parotid gland.

2. CN VIII is a special sensory nerve, i.e. no cutaneous innervation.

3. Not sure what the question is here.

if you are talking about nerves ,you would know the basic better ,could you explain the question i asked

trigeminal nucleus is connected to coretex where pain is felt. my question is does trigeminal nucleus in the cns has cellbody,axon and dentristes like trigeminal ganglia.thanks

 

[Sim2khah]

hi .......

wish u all doing well
would u plz explain the answer to this question?

for which is the first group of following pairs more likely to be located on the surface of globular protein than the second group pair?

CONH2 COO
CH3 CH(CH3)2
CH2OH NH4
CH3 CH2OH
CH2SH COO

PLZZZZ EXPLAIN WHy

 

[Sim2khah]

Refer N series,
Q 24 Which Amino Acid possesses a hydrophobic side chain?
a Lysine
b Cysteine
c Leucine
d hydroxyproline
e glycine

my answer.... glycine and Leucine,
key answer is leucine... 😕

Q113
Gel Electrophoresis is used to separate molecules by
a shape
b charge
c viscosity
d mass & shape
e charge and size
My answer b... charge, key answer e... plz explain

for the first question, although glycin is ahydrophobic amino acid, it doesnt have side chain so it should be left out.

 

[Sim2khah]

I-C biochemistry question 61

The osmotic pressure of the filtrate at the end of the proximal convoluted tubule is
1. greater than that of plasma
2. much less than that of plasma
3. about the same as that of plasma
4. greate than that of the filtrate in the descending portion of the loop of henle.

the ans is 3

can't understand it, since the descending limb is still reabsorting water due to osmosis

I looked this up in the guyton physiology book, here is some extra information:

In the proximal tubule, the amount sodium decreases, but its concentration does not change. that is due the fact that this part of nephron is highly permeable to water, so water follows sodium. the result is that sodium concentration ( and the total osmolarity) does not change.

with regardes to other material, such as glucose, amino acid, and bicarbonte,their concentration decreases along the proximal tubule as they are reabsorbed even more greedily! than water.

proximal tubule is not that permeable to urea, so its concentration increases at the end of proximal tubule.

as a whole in proximal tubule:
Na osmolarity is constant
urea concentration increses
bicarbonate, glucose, amino acids concentration decrease

 

[firefoxdental]

look to the next post

 

[firefoxdental]

Acetlycholine is released in at all of the following junctions except

1.Sympathetic ganglia
2.Parasympathetic ganglia
3.Somatic efferents to skeletal muscles
4.terminal sympathetic fibers to the heart
5.terminal sympathetic fibers to the adrenal medulla

ans is 4.

all pre ganglionic and post ganglionic fib release Ach except for post gagnlionic sympathetic that release norepinephrine, except at sweat glands and skeletal muscle areterioles.

can anyone explain this.

would appreciate it.

http://www.smbs.buffalo.edu/ana/newpage41.htm

after checking this ,if u have any doubt , just pm me.

 

[buntydr83]

question:
iron porphyrin protein structures are components of?
1. hemoglobin
2.myoglobin
3.cytochromes

 

[buntydr83]

march 23rd!!! im freaked out! haha.. lets see what happens...

good luck amreki....

 

[buntydr83]

general reaction of transfer of "one carbon fragment require coenzyme
1. vit-B6
2. vit-B1
3.tetra hydrofolic acid

 

[Amreki]

i didnt know the coenzyme question, but the answer is Tetrahydrofolic acid

http://en.wikipedia.org/wiki/Tetrahydrofolate


as for the porphryin ring question.. i think all 3 have them as they all contain heme groups... so the answer would be all of the above.



and thanks bunty!

 

[Amreki]

hey can someone help me out in understanding this question? my test is in like 10 days so it would be much appreciated.

test packet I-B question 88

In which segment of the nephron does the tubular fluid have the highest osmolality?

1) henle's loop
2) distal tubule
3) proximal tubule
4) collecting duct
5) bowmans duct


the answer is 1 , Henle's loop.


The way I understand osmolality is that the higher amounts of solutes in the fluid with less water = Increased Osmolality.

Secondly, henle's loop is impermeable to water, but sodium potassium and chloride are involved in reabsoprtion in this segment. Its primary purpose to create the gradient in the medulla of the kidneys. Essentially, I thought the henle's loop would have Decreased solute and No water reabsorption meaning decreased osmolality.

My answer would have been collecting tubule due to the fact that this is where urine can be really concentrated with ADH.


Can someone please go through all my assumptions and tell me where I went wrong in answering this question. It would be most appreciated!

 

[amalgamated80]

good luck on ur test amreki!!! here is my understanding of the countercurrent mechanism and hope it helps....


Descending loop of henle is relatively permeable to water and relatively impermeable to all solutes except for urea. The fluid surrounding descending loop of henle - that is the interstitial fluid is more concentrated than the tubular fluid. So water moved out to the interstitial fluid as liquid flows downwards the descending loop of henle. This makes the tubular fluid progressively concentrated and by the time it reaches hair pin turn its very highly concentrated. Now the ascending loop is relatively impermeable to water( opposite of descending loop) and had sodium, potassium and chloride symporters. The symporters reabsorb Na,K and Cl ions from tubular fluid and send it to the interstitial fluid. So although no water is being reabsorbed, ions r moving out. so the tubular fluid in the ascenign loop of henle is getting to be dilute cause of loss of ions. So to be specific descenging loop of henle has the highest osmolality. now collecting duct cannot be the place of highest osmolality i think because thats where ions are being secreted into in tubular secretion and also adh acts on collecting tubules for water reabsorption , so the osmolality might not be as high as the fluid might not be as concentrated in comparison to the fluid in descending loop. hope this makes sense . i think this is why it wud be loop of henle, correct me if im wrong.

 

[Amreki]

hey thanks alot amalgamated! i totally forgot about the descending loop of henle and was more focused on the ascending loop 🙂 . it makes sense now thanks!

 

[Anaita]

hi anaita, answer is leucine, it is confirmed. i remember, i have shared a link on this. you lok on google and you will find out that one of them is strongly hydrophobic and other is weakly hydrophobic, hence leucine is a confirmed and right answer.

Thnx teethie!! Am back at Biochem these days!!

 

[Anaita]

👍👍

1. Auriculotemporal nerve is purely sensory, lesser petrosal travels with it on its way to parasympathetic innervation to the parotid gland.

2. CN VIII is a special sensory nerve, i.e. no cutaneous innervation.

3. Not sure what the question is here.

 

[Anaita]

general reaction of transfer of "one carbon fragment require coenzyme
1. vit-B6
2. vit-B1
3.tetra hydrofolic acid

Vitamin B6 is a coenzyme in Amino Acid transamination reactions, Vitamin B1 (thymine) in Dehdrogenase reactions... remember that reference to reactions requiring (Tender loving care for Nancy... 🙂)) so leaves us only with THF or folate.. still have to do Vitamins.. so will get back soon........... do correct me if i'm wrong

 

[Anaita]

Vitamin B6 is a coenzyme in Amino Acid transamination reactions, Vitamin B1 (thymine) in Dehdrogenase reactions... remember that reference to reactions requiring (Tender loving care for Nancy... 🙂)) so leaves us only with THF or folate.. still have to do Vitamins.. so will get back soon........... do correct me if i'm wrong

Yes... THF it is in Methylation of Uracil... so let's do our purines and pyrimidines..🙂

 

[Anaita]

hey thanks alot amalgamated! i totally forgot about the descending loop of henle and was more focused on the ascending loop 🙂 . it makes sense now thanks!

Best of luck Amreki 🙂

 

[Amreki]

thanks alot anaita! really nervous !

 

[Anaita]

hi .......

wish u all doing well
would u plz explain the answer to this question?

for which is the first group of following pairs more likely to be located on the surface of globular protein than the second group pair?

CONH2 COO
CH3 CH(CH3)2
CH2OH NH4
CH3 CH2OH
CH2SH COO

PLZZZZ EXPLAIN WHy

😕 i havent even understood the question!! Plz explain again n where did you get this one from???

 

[Anaita]

hi .......

wish u all doing well
would u plz explain the answer to this question?

for which is the first group of following pairs more likely to be located on the surface of globular protein than the second group pair?

CONH2 COO
CH3 CH(CH3)2
CH2OH NH4
CH3 CH2OH
CH2SH COO

PLZZZZ EXPLAIN WHy

The combination of carbons and hydrogens as in hydrocarbons or in the hydrocarbon portion of a molecule with a functional group is always NON-POLAR.
On a polarity scale
Amide > Acid > Alcohol > Amine > Ether > Alkane
So CH3OH > NH4... and so perhaps the first of the pair would be on the surface... correct me if i'm wrong

 

[Anaita]

I feel that the correct answer is A.
I searched for the most polar gorups and Amide is the most polar.
The sequence of most polar groups is this:
Amide>Acid>Alcohol>ketone>aldehyde>Amine>Ester>Ether>Alkane.

So I feel choice A is the only one that fits the bill. It is indeed one of the tougher questions!

Thanx Gotaf... God Bless You!!

 

[perfectionist1]

Hey Anaita...Long time. Hows the prep going or are you already done with the exam?