NBME 29
1
Exam Section 1: Item 1 of 50
National Board of Medical Examiners'
Comprehensive Basic Science Self-Assessment
1. Patients with extended starvation or untreated type 1 diabetes mellitus overproduce
ketone bodies. Which of the following is a common aspect this is accountable for ketosis in
patients with
these conditions?
A) Depletion of pentose phosphate pathway intermediates
B) Increased availability of acetyl COA
C) Inhibition of fatty acid oxidation
D) Inhibition of gluconeogenesis
E) Inhibition of glycogenolysis - ANS-B.
Increased availability of acetyl CoA is not unusual to states of starvation and untreated kind
1 diabetes mellitus. In starvation, glycogen stores are steadily depleted. The body then relies
on the
breakdown of fats via oxidation of fatty acids to provide energy. Fatty acid oxidation occurs in
the mitochondria of the cellular. In every cycle of oxidation, -carbon fragments are cleaved to
form
acetyl CoA, which leaves the mitochondria through the carnitine shuttle. In addition to a
molecule of acetyl CoA which then enters the citric acid cycle, a molecule of NADH is
produced in every cycle.
Ketogenesis occurs in starvation thru -carbon fragments, with formation of ketoacids
consisting of acetoacetyl CoA and B-hydroxybutyrate. The potential to generate strength
from adipose in the course of a
period of hunger is important to keeping the feature of important organs, along with the
brain. In untreated type 1 diabetes mellitus, there is an absolute deficiency of insulin, which
renders many
cells incapable of shuttling glucose into the mobile to be used in cellular respiratory. While
there are numerous glucose transporters that don't require insulin for glucose entry, GLUT4
is normally
expressed in lots of cellular sorts and calls for insulin to function. Patients with untreated kind
1 diabetes mellitus may have serum glucose concentrations within the high-ordinary to high
variety as a end result
of ongoing gluconeogenesis and glycogenolysis, but insulin deficiency prevents entry of
circulating glucose into cells through glucose transport proteins, efficiently resulting in a
country of
hunger. This consequences in ketogenesis and accounts for the presence of ketone bodies
within the blood and urine of sufferers with hunger or untreated type 1 diabetes mellitus.
Incorrect Answers: A, C, D, and E.
Depletion of pentose phosphate pathway intermediates (Choice A) is not accurate.
10
,Exam Section 1: Item 10 of 50
National Board of Medical Examiners'
Comprehensive Basic Science Self-Assessment
10. A 33-year-antique girl involves the physician because of fatigue for 2 months; she feels
nicely otherwise. She has a ten-12 months records of systemic lupus erythematosus treated
with prednisone.
Physical examination suggests no abnormalities. Laboratory studies show:
9.0 g/dL
27%
8500/mm3
0.2%
Hemoglobin
Hematocrit
Leukocyte be counted
Reticulocyte matter
Platelet depend
one hundred ninety,000/mm3
Serum
Ferritin
Iron
Total iron-binding ability
Red cell morphology
250 ng/mL
10 pug/dL
100 ug/dL (N=250-400)
normochromic, normocytic
Which of the following is the most probably reason of this patient's anemia?
A) Accumulation of iron within mitochondria of erythroblasts
B) Decreased serum concentrations of hepcidin
O C) Decreased serum concentrations of inflammatory cytokines
D) Decreased uptake of iron by means of bone marrow macrophages
E) Increased - ANS-E.
Increased retention of iron inside the reticuloendothelial device (RES) is function of anemia
of persistent ailment (ACD) and is the most probable reason of anemia in this patient with
systemic
lupus erythematosus (SLE). ACD is not unusual in sufferers with rheumatologic disorders
which include SLE or rheumatoid arthritis and those with chronic infections, renal disease, or
malignancies.
Chronic irritation with launch of inflammatory materials together with interleukin-1 and tumor
necrosis element-a lead to an growth in hepcidin production, a decreased responsiveness of
the
bone marrow to erythropoietin, and retention of iron within the RES. This confluence of
factors ends in impaired iron absorption and recycling, with a consequent country of useful
iron
deficiency despite ok iron shops. Iron this is retained in the RES can not efficiently be
accessed and used for erythropoiesis, so patients present with either normocytic or
microcytic
,anemia and reduced numbers of reticulocytes indicating inadequate bone marrow response
to anemia. Other laboratory findings include a everyday to slightly improved ferritin
concentration,
that's the storage shape of iron, decreased serum iron attention, and a reduced overall
iron-binding capacity (TIBC). If doubt exists in distinguishing among ACD and iron deficiency
anemia, dimension of the soluble transferrin receptor may be beneficial.
Incorrect Answers: A, B, C, and D.
Accumulation of iron inside mitochondria of erythroblasts (Choice A) happens in sufferers
with porphyria cutanea tarda, sideroblastic anemia, and B-thalassemia predominant, but no
longer in ACD.
Decreased serum concentrations of hepcidin (Choice B) do no longer arise in ACD. On the
opposite, increased concentrations of hepcidin in ACD impair the absorption of iron inside
the intestine and the release
of iron from macrophages. This takes place
100
Exam Section 2: Item 50 of fifty
National Board of Medical Examiners'
Comprehensive Basic Science Self-Assessment
50. A healthful 30-yr-vintage female is traveling on a industrial airliner where the cabin's
barometric stress is measured at 565 mm Hg. The inspiratory partial stress of alveolar
oxygen in
this girl is most possibly which of the following (in mm Hg)?
A) 27
B) 60
C) 109
D) 515
E) 713 - ANS-C.
The alveolar gas equation may be used to calculate the inspiratory partial strain of oxygen at
a given atmospheric stress. The equation is P;02 = F;02 x (PATM - PH20) where P;02 is the
partial strain of stimulated oxygen, F;O2 is the fraction of stimulated oxygen, PATM is the
atmospheric stress, and PH2O is the partial stress of water vapor. The fraction of stimulated
oxygen is
21%, or 0.21, and is unchanged at modest altitude, as is the water vapor stress, which is
expected at 47 mm Hg. Inserted into the equation, P;O2 = zero.21 x (565 mm Hg - 47 mm
Hg) = 109
%3-d
mm Hg. This represents the partial pressure of oxygen that is inspired by the younger female
in the pressurized cabin.
Incorrect Answers: A, B, D, and E.
27 (Choice A) isn't the best solution and represents using faulty numbers or miscalculations.
60 (Choice C) represents the alveolar partial stress of oxygen, no longer the inspiratory
partial pressure, that is calculated by way of adjusting the inspiratory partial strain of alveolar
oxygen to
accommodate the partial stress of alveolar carbon dioxide: PAO2 = F;02 x (PATM - PH20) -
(PACO2/breathing alternate ratio), in which PAO2 is the alveolar partial pressure of oxygen,
and
PACO2 is the arterial stress of carbon dioxide). The affected person is a younger, healthy
grownup, and the expected PACO2 might be 40 mm Hg.
, 515 (Choice D) represents the difference among the atmospheric stress within the cabin and
the ratio of the arterial partial stress of carbon dioxide to breathing change ratio. This
calculation, 565 mm Hg - (40 mm Hg / zero.Eight) = 565 mm Hg - 50 mm Hg = 515 mm Hg,
neglects the fraction of stimulated oxygen and the water vapor stress.
713 (Choice E) represents the distinction between the atmospheric pressure and water
vapor pressure at sea level. These values are normally approximated as 760 mm Hg
one hundred and one
Exam Section 3: Item 1 of fifty
National Board of Medical Examiners'
Comprehensive Basic Science Self-Assessment
1. A 20-year-vintage man is delivered to the doctor by using his mother because of weird
conduct for six months. Although he had constantly been a terrific student, he failed all his
instructions at college closing
term. He now not showers or shaves, and his appearance has end up raveled and unkempt.
He appears distracted at the beginning of the interview after which starts offevolved talking
nonstop to
unseen people within the nook of the inspecting room. His mom appears disenchanted and
says, "It appears as though he is listening to voices all of the time now. He's without a doubt
scaring our family." Which of the
following preliminary responses by the physician is most suitable?
A) "He should be schizophrenic. Does schizophrenia run for your husband's own family or
yours?"
B) "He desires to take a shower. Have you tried sitting down with him and speakme to him
about taking bet - ANS-C.
This health practitioner have to validate the mother's emotion and then ask an open-ended
question. When sufferers or family individuals display or describe an emotion at the same
time as discussing a medical difficulty,
the physician should validate the emotion. There are several techniques to validate emotion:
being gift (actively listening and indicating information thru nonverbal cues together with
nodding),
accurate reflection (restating a patient's phrases, as this physician did), mind-reading
(inferring the emotional content in the back of the affected person's phrases), and
normalizing (recognizing the affected person's response
as a reaction another individual would have). The subsequent step in investigating any
medical issue is to invite an open-ended question so that the patient or family member can
difficult on their
challenge. This patient might also have an underlying number one psychiatric (eg,
schizophrenia) or substance-prompted psychotic ailment, and the health practitioner need to
allow the mom to provide extra details
and perceive her concerns and priorities. Patients with schizophrenia show two clusters of
signs and symptoms: nice symptoms (addition of intellectual disorder inclusive of delusions,
hallucinations, and
disorganized thinking and conduct) and negative signs and symptoms (absence of certain
mental features consisting of have an effect on, volition, and speech). Negative signs and
symptoms may manifest as poor personal
hygiene.
Incorrect Answers: A, B, D, and E.
1
Exam Section 1: Item 1 of 50
National Board of Medical Examiners'
Comprehensive Basic Science Self-Assessment
1. Patients with extended starvation or untreated type 1 diabetes mellitus overproduce
ketone bodies. Which of the following is a common aspect this is accountable for ketosis in
patients with
these conditions?
A) Depletion of pentose phosphate pathway intermediates
B) Increased availability of acetyl COA
C) Inhibition of fatty acid oxidation
D) Inhibition of gluconeogenesis
E) Inhibition of glycogenolysis - ANS-B.
Increased availability of acetyl CoA is not unusual to states of starvation and untreated kind
1 diabetes mellitus. In starvation, glycogen stores are steadily depleted. The body then relies
on the
breakdown of fats via oxidation of fatty acids to provide energy. Fatty acid oxidation occurs in
the mitochondria of the cellular. In every cycle of oxidation, -carbon fragments are cleaved to
form
acetyl CoA, which leaves the mitochondria through the carnitine shuttle. In addition to a
molecule of acetyl CoA which then enters the citric acid cycle, a molecule of NADH is
produced in every cycle.
Ketogenesis occurs in starvation thru -carbon fragments, with formation of ketoacids
consisting of acetoacetyl CoA and B-hydroxybutyrate. The potential to generate strength
from adipose in the course of a
period of hunger is important to keeping the feature of important organs, along with the
brain. In untreated type 1 diabetes mellitus, there is an absolute deficiency of insulin, which
renders many
cells incapable of shuttling glucose into the mobile to be used in cellular respiratory. While
there are numerous glucose transporters that don't require insulin for glucose entry, GLUT4
is normally
expressed in lots of cellular sorts and calls for insulin to function. Patients with untreated kind
1 diabetes mellitus may have serum glucose concentrations within the high-ordinary to high
variety as a end result
of ongoing gluconeogenesis and glycogenolysis, but insulin deficiency prevents entry of
circulating glucose into cells through glucose transport proteins, efficiently resulting in a
country of
hunger. This consequences in ketogenesis and accounts for the presence of ketone bodies
within the blood and urine of sufferers with hunger or untreated type 1 diabetes mellitus.
Incorrect Answers: A, C, D, and E.
Depletion of pentose phosphate pathway intermediates (Choice A) is not accurate.
10
,Exam Section 1: Item 10 of 50
National Board of Medical Examiners'
Comprehensive Basic Science Self-Assessment
10. A 33-year-antique girl involves the physician because of fatigue for 2 months; she feels
nicely otherwise. She has a ten-12 months records of systemic lupus erythematosus treated
with prednisone.
Physical examination suggests no abnormalities. Laboratory studies show:
9.0 g/dL
27%
8500/mm3
0.2%
Hemoglobin
Hematocrit
Leukocyte be counted
Reticulocyte matter
Platelet depend
one hundred ninety,000/mm3
Serum
Ferritin
Iron
Total iron-binding ability
Red cell morphology
250 ng/mL
10 pug/dL
100 ug/dL (N=250-400)
normochromic, normocytic
Which of the following is the most probably reason of this patient's anemia?
A) Accumulation of iron within mitochondria of erythroblasts
B) Decreased serum concentrations of hepcidin
O C) Decreased serum concentrations of inflammatory cytokines
D) Decreased uptake of iron by means of bone marrow macrophages
E) Increased - ANS-E.
Increased retention of iron inside the reticuloendothelial device (RES) is function of anemia
of persistent ailment (ACD) and is the most probable reason of anemia in this patient with
systemic
lupus erythematosus (SLE). ACD is not unusual in sufferers with rheumatologic disorders
which include SLE or rheumatoid arthritis and those with chronic infections, renal disease, or
malignancies.
Chronic irritation with launch of inflammatory materials together with interleukin-1 and tumor
necrosis element-a lead to an growth in hepcidin production, a decreased responsiveness of
the
bone marrow to erythropoietin, and retention of iron within the RES. This confluence of
factors ends in impaired iron absorption and recycling, with a consequent country of useful
iron
deficiency despite ok iron shops. Iron this is retained in the RES can not efficiently be
accessed and used for erythropoiesis, so patients present with either normocytic or
microcytic
,anemia and reduced numbers of reticulocytes indicating inadequate bone marrow response
to anemia. Other laboratory findings include a everyday to slightly improved ferritin
concentration,
that's the storage shape of iron, decreased serum iron attention, and a reduced overall
iron-binding capacity (TIBC). If doubt exists in distinguishing among ACD and iron deficiency
anemia, dimension of the soluble transferrin receptor may be beneficial.
Incorrect Answers: A, B, C, and D.
Accumulation of iron inside mitochondria of erythroblasts (Choice A) happens in sufferers
with porphyria cutanea tarda, sideroblastic anemia, and B-thalassemia predominant, but no
longer in ACD.
Decreased serum concentrations of hepcidin (Choice B) do no longer arise in ACD. On the
opposite, increased concentrations of hepcidin in ACD impair the absorption of iron inside
the intestine and the release
of iron from macrophages. This takes place
100
Exam Section 2: Item 50 of fifty
National Board of Medical Examiners'
Comprehensive Basic Science Self-Assessment
50. A healthful 30-yr-vintage female is traveling on a industrial airliner where the cabin's
barometric stress is measured at 565 mm Hg. The inspiratory partial stress of alveolar
oxygen in
this girl is most possibly which of the following (in mm Hg)?
A) 27
B) 60
C) 109
D) 515
E) 713 - ANS-C.
The alveolar gas equation may be used to calculate the inspiratory partial strain of oxygen at
a given atmospheric stress. The equation is P;02 = F;02 x (PATM - PH20) where P;02 is the
partial strain of stimulated oxygen, F;O2 is the fraction of stimulated oxygen, PATM is the
atmospheric stress, and PH2O is the partial stress of water vapor. The fraction of stimulated
oxygen is
21%, or 0.21, and is unchanged at modest altitude, as is the water vapor stress, which is
expected at 47 mm Hg. Inserted into the equation, P;O2 = zero.21 x (565 mm Hg - 47 mm
Hg) = 109
%3-d
mm Hg. This represents the partial pressure of oxygen that is inspired by the younger female
in the pressurized cabin.
Incorrect Answers: A, B, D, and E.
27 (Choice A) isn't the best solution and represents using faulty numbers or miscalculations.
60 (Choice C) represents the alveolar partial stress of oxygen, no longer the inspiratory
partial pressure, that is calculated by way of adjusting the inspiratory partial strain of alveolar
oxygen to
accommodate the partial stress of alveolar carbon dioxide: PAO2 = F;02 x (PATM - PH20) -
(PACO2/breathing alternate ratio), in which PAO2 is the alveolar partial pressure of oxygen,
and
PACO2 is the arterial stress of carbon dioxide). The affected person is a younger, healthy
grownup, and the expected PACO2 might be 40 mm Hg.
, 515 (Choice D) represents the difference among the atmospheric stress within the cabin and
the ratio of the arterial partial stress of carbon dioxide to breathing change ratio. This
calculation, 565 mm Hg - (40 mm Hg / zero.Eight) = 565 mm Hg - 50 mm Hg = 515 mm Hg,
neglects the fraction of stimulated oxygen and the water vapor stress.
713 (Choice E) represents the distinction between the atmospheric pressure and water
vapor pressure at sea level. These values are normally approximated as 760 mm Hg
one hundred and one
Exam Section 3: Item 1 of fifty
National Board of Medical Examiners'
Comprehensive Basic Science Self-Assessment
1. A 20-year-vintage man is delivered to the doctor by using his mother because of weird
conduct for six months. Although he had constantly been a terrific student, he failed all his
instructions at college closing
term. He now not showers or shaves, and his appearance has end up raveled and unkempt.
He appears distracted at the beginning of the interview after which starts offevolved talking
nonstop to
unseen people within the nook of the inspecting room. His mom appears disenchanted and
says, "It appears as though he is listening to voices all of the time now. He's without a doubt
scaring our family." Which of the
following preliminary responses by the physician is most suitable?
A) "He should be schizophrenic. Does schizophrenia run for your husband's own family or
yours?"
B) "He desires to take a shower. Have you tried sitting down with him and speakme to him
about taking bet - ANS-C.
This health practitioner have to validate the mother's emotion and then ask an open-ended
question. When sufferers or family individuals display or describe an emotion at the same
time as discussing a medical difficulty,
the physician should validate the emotion. There are several techniques to validate emotion:
being gift (actively listening and indicating information thru nonverbal cues together with
nodding),
accurate reflection (restating a patient's phrases, as this physician did), mind-reading
(inferring the emotional content in the back of the affected person's phrases), and
normalizing (recognizing the affected person's response
as a reaction another individual would have). The subsequent step in investigating any
medical issue is to invite an open-ended question so that the patient or family member can
difficult on their
challenge. This patient might also have an underlying number one psychiatric (eg,
schizophrenia) or substance-prompted psychotic ailment, and the health practitioner need to
allow the mom to provide extra details
and perceive her concerns and priorities. Patients with schizophrenia show two clusters of
signs and symptoms: nice symptoms (addition of intellectual disorder inclusive of delusions,
hallucinations, and
disorganized thinking and conduct) and negative signs and symptoms (absence of certain
mental features consisting of have an effect on, volition, and speech). Negative signs and
symptoms may manifest as poor personal
hygiene.
Incorrect Answers: A, B, D, and E.
