USMLE Step 1 – Complete Exam Prep & Study Resources (Latest Update
2025/2026)
What are the two major microtubular motor proteins? Which does anterograde axonal
transport, which does retrograde axonal transport? correct answers Kinesin, Dynein
Kinesin: Anterograde
Dynein: Retrograde`
What do you think, immunologically speaking, when you see someone with recurrent
Neisseria infections? correct answers Inability to form the membrane attack (MAC)
complex
this is a common complement deficiency
What is the defect in Chronic Granulomatous disease? What is the pathophysiology?
correct answers NADPH Oxidase deficiency leads to the inability to kill intracellular
organisms
Characteristic triad of ataxia telangiectasia? correct answers cerebellar ataxia,
telangiectasias, increased risk of sinopulmonary infections
What is the major immune deficiency of ataxia telangiectasia? correct answers IgA
deficiency, which predisposes to infections of the upper and lower airways (and other
mucous membranes)
There's a useful mnemonic for Ataxia Telangiectasia and the gene that's mutated. What
is it? correct answers ATM
Ataxia
Telangiectasia
Mutated
ATM gene is responsible for DNA break repair
What is one reason that lead intoxication causes hypochromic anemia? correct answers
Mitochondrial iron transport is important for Heme synthesis! It's inhibited by lead. So
you don't make heme in your mitochondria and you get hypochromic anemia.
What is the biochemical problem in Lesch-Nyhan syndrome? (And, only if you got that
right, what are the really cool symptoms of it?) correct answers Defective purine
catabolism, so buildup of purines. It's an X-linked recessive disorder with mutated
HGPRT gene (hypoxanthine-guanine phosphoribosyltransferase, if you want to impress
people).
,Now, if you got HGPRT and purine catabolism right, you can say: self-mutilating
behavior on top of mental retardation, choreoathetoid (think Chorea) movements and
spasticity.
What is the defect in Niemann-Pick disease?
What causes that?
What is the common macular finding? correct answers Sphingolipid degradation is
defective
Caused by an autosomal recessive defect in sphingomyelinase
Cherry Spot on the macula? Niemann Pick's or Tay Sach's.
If a baby gets exposed to an unclean knife (...) and subsequently develops rigid
paralysis, what is the diagnosis, where do we think this might happen, and how do we
prevent it? correct answers Neonatal Tetanus
Developing Countries
Maternal immunization with tetanus toxoid is the best way to prevent it
an adeuately immunized mom will transfer IgG's across the placenta to the neonate
Which microtubule associated protein aids in anterograde transport of intracellular
vesicles and organelles? Which end of the microtubule do they go towards? correct
answers Kinesin.
Towards the (+) rapidly growing end.
What is an early BRAIN finding of Ataxia-Telangiectasia and how does it manifest itself?
correct answers Cerebellar atrophy
manifests as ataxia in the first years of life.
High yield path association for Alzheimer's disease? correct answers Neurofibrillary
tangles in the neocortex
High yield path association for Parkinson's disease? correct answers Loss of neurons in
the substantia nigra
High yield path association for Huntington disease? correct answers Atrophy of caudate
nucleus
What are the major manifestations of Ataxia-telangiectasia? correct answers cerebellar
ataxia, oculocutaneous tenlangiectasias, repeated sinopulmonary infections, and an
increased incidence of malignancy
If you heard: amenorrhea, bitemporal hemianopsia, and enlargement of the pituitary
gland on brain imaging, what would you be thinking? correct answers Prolactinoma, the
most common pituitary adenoma.
,What embryological layer is the anterior pituitary derived from? correct answers Surface
ectoderm
What is the most common congenital abnormality associated with the use of Sodium
Valproate during pregnancy? correct answers neural tube defects, e.g., meningocele
because valproate inhibits intestinal folic acid absorption resulting in teratogenicity
What is the characteristic histology of a craniopharyngioma? correct answers On light
microscopy, cysts are lined by stratified squamous epithelium, possibly with Keratin
perals. Cysts are usually filled iwth a yellow, viscous fluid that's rich in cholesterol
crystals.
Where do craniopharyngyomas arise from? correct answers Craniopharyngiomas are
calcified cystic tumors that arise from remnants of Rathke's pouch (embryonic precuros
of the anterior pituitary)
Failure of what process leads due neural tube defects? What can be seen in the
amniotic fluid due to leakage of fetal cebebrospinal fluid? correct answers Failure of
fusion of the neuropores.
Alpha-fetoprotein and Acetylcholinesterase may appear in the amniotic fluid
Can a competent patient refuse healthcare? Can a competent patient refuse knowledge
of their potential health situation? correct answers yes and yes
What is the consensus and professional standard regarding the receiving of gifts from
patients? correct answers Don't do it. It's unethical to accept individual gifts from
patients, especially of signficant value.
AMA doesn't have clear cut answer, but they recommend careful consideration be used.
some general guidelines:
-cash gifts should never be accepted (this includes gift certificates)
-a gift should never influence treatment
-no specific dollar value is given; but as a rule of thumb, it shouldn't be above patient's
or physician's means
-psychiatrist must be super careful even with small gifts
-maintain consistency among all patients
-if physician would be embarrassed or uncomfortable if his colleagues found out about
the gift, don't accept it
Is displacement a mature or immature defense mechanism? What is displacement?
correct answers Immature. A patient redirects emotions from the person or object that's
causing the emotions (e.g., wife), but who it woudl be completely unacceptable to direct
, those emotions toward, to a more acceptable, but still inappropriate, person or object
(e.g., a wall or a vase).
Is sublimation a mature or immature defense mechanism? How does it work? correct
answers Mature. Unacceptable drives are redirected toward completely acceptable
targets. (Workout hard if you're angry)
Is projection a mature or immature defense mechanism? What is it? correct answers
Immature. Unacceptable or personally disagreeable impulses are attributed to others;
e.g., a student who wants to cheat on a test accuses his classmates of cheating. Or the
gayness thing
Is reaction formation immature or mature defense mechanism? what is it? correct
answers immature, where unacceptable feeligns are IGNORED and the opposite
sentiment is adopted (forced). man who's mad at his wife instead compliments her
dress
Is splitting a mature or immature defense mechanism? what is it? correct answers
immature. frequently employed by patients with borderline personality disorder,
everything is either "good or bad."
What do you do if you suspect child abuse? Ask the parents or call child protective
services? correct answers Call Child Protective Services immediately!
Psychologically speaking, what phenomenon is "white coat syndrome" associated with?
correct answers Classical Conditioning. In classical conditioning, a reflexive response
normally elicited by an unconditioned stimulus becomes evocable by a second, formally
neutral (conditioned) stimulus.
What three things can patients with bulimia develop (hint: one isn't weight loss because
bulimia doesn't work.)? correct answers (1) bilateral partodi gland enlargement
(2) erosion of tooth enamel*
(3) irregular menses
What is the pulmonary capillary wedge pressure and what does it indirectly measure?
correct answers Pressure in the pulmonary artey distal to the point of its occlusion by an
inflated intravascular balloon.
Since there's no significant blood flow towards the left atrium (LA) beyong this point of
occlusion, the pressure at the tip of the "wedged" pulmonary artery catheter is an
indirect measurement of LA Pressure.
What would we expect, in a normal patient, the relationship to be between LA and LV
pressure during diastole? correct answers We would expect them to be nearly equale
(both <12) since the open mitral valve offers minimal resistance to flow between the 2
chambers
2025/2026)
What are the two major microtubular motor proteins? Which does anterograde axonal
transport, which does retrograde axonal transport? correct answers Kinesin, Dynein
Kinesin: Anterograde
Dynein: Retrograde`
What do you think, immunologically speaking, when you see someone with recurrent
Neisseria infections? correct answers Inability to form the membrane attack (MAC)
complex
this is a common complement deficiency
What is the defect in Chronic Granulomatous disease? What is the pathophysiology?
correct answers NADPH Oxidase deficiency leads to the inability to kill intracellular
organisms
Characteristic triad of ataxia telangiectasia? correct answers cerebellar ataxia,
telangiectasias, increased risk of sinopulmonary infections
What is the major immune deficiency of ataxia telangiectasia? correct answers IgA
deficiency, which predisposes to infections of the upper and lower airways (and other
mucous membranes)
There's a useful mnemonic for Ataxia Telangiectasia and the gene that's mutated. What
is it? correct answers ATM
Ataxia
Telangiectasia
Mutated
ATM gene is responsible for DNA break repair
What is one reason that lead intoxication causes hypochromic anemia? correct answers
Mitochondrial iron transport is important for Heme synthesis! It's inhibited by lead. So
you don't make heme in your mitochondria and you get hypochromic anemia.
What is the biochemical problem in Lesch-Nyhan syndrome? (And, only if you got that
right, what are the really cool symptoms of it?) correct answers Defective purine
catabolism, so buildup of purines. It's an X-linked recessive disorder with mutated
HGPRT gene (hypoxanthine-guanine phosphoribosyltransferase, if you want to impress
people).
,Now, if you got HGPRT and purine catabolism right, you can say: self-mutilating
behavior on top of mental retardation, choreoathetoid (think Chorea) movements and
spasticity.
What is the defect in Niemann-Pick disease?
What causes that?
What is the common macular finding? correct answers Sphingolipid degradation is
defective
Caused by an autosomal recessive defect in sphingomyelinase
Cherry Spot on the macula? Niemann Pick's or Tay Sach's.
If a baby gets exposed to an unclean knife (...) and subsequently develops rigid
paralysis, what is the diagnosis, where do we think this might happen, and how do we
prevent it? correct answers Neonatal Tetanus
Developing Countries
Maternal immunization with tetanus toxoid is the best way to prevent it
an adeuately immunized mom will transfer IgG's across the placenta to the neonate
Which microtubule associated protein aids in anterograde transport of intracellular
vesicles and organelles? Which end of the microtubule do they go towards? correct
answers Kinesin.
Towards the (+) rapidly growing end.
What is an early BRAIN finding of Ataxia-Telangiectasia and how does it manifest itself?
correct answers Cerebellar atrophy
manifests as ataxia in the first years of life.
High yield path association for Alzheimer's disease? correct answers Neurofibrillary
tangles in the neocortex
High yield path association for Parkinson's disease? correct answers Loss of neurons in
the substantia nigra
High yield path association for Huntington disease? correct answers Atrophy of caudate
nucleus
What are the major manifestations of Ataxia-telangiectasia? correct answers cerebellar
ataxia, oculocutaneous tenlangiectasias, repeated sinopulmonary infections, and an
increased incidence of malignancy
If you heard: amenorrhea, bitemporal hemianopsia, and enlargement of the pituitary
gland on brain imaging, what would you be thinking? correct answers Prolactinoma, the
most common pituitary adenoma.
,What embryological layer is the anterior pituitary derived from? correct answers Surface
ectoderm
What is the most common congenital abnormality associated with the use of Sodium
Valproate during pregnancy? correct answers neural tube defects, e.g., meningocele
because valproate inhibits intestinal folic acid absorption resulting in teratogenicity
What is the characteristic histology of a craniopharyngioma? correct answers On light
microscopy, cysts are lined by stratified squamous epithelium, possibly with Keratin
perals. Cysts are usually filled iwth a yellow, viscous fluid that's rich in cholesterol
crystals.
Where do craniopharyngyomas arise from? correct answers Craniopharyngiomas are
calcified cystic tumors that arise from remnants of Rathke's pouch (embryonic precuros
of the anterior pituitary)
Failure of what process leads due neural tube defects? What can be seen in the
amniotic fluid due to leakage of fetal cebebrospinal fluid? correct answers Failure of
fusion of the neuropores.
Alpha-fetoprotein and Acetylcholinesterase may appear in the amniotic fluid
Can a competent patient refuse healthcare? Can a competent patient refuse knowledge
of their potential health situation? correct answers yes and yes
What is the consensus and professional standard regarding the receiving of gifts from
patients? correct answers Don't do it. It's unethical to accept individual gifts from
patients, especially of signficant value.
AMA doesn't have clear cut answer, but they recommend careful consideration be used.
some general guidelines:
-cash gifts should never be accepted (this includes gift certificates)
-a gift should never influence treatment
-no specific dollar value is given; but as a rule of thumb, it shouldn't be above patient's
or physician's means
-psychiatrist must be super careful even with small gifts
-maintain consistency among all patients
-if physician would be embarrassed or uncomfortable if his colleagues found out about
the gift, don't accept it
Is displacement a mature or immature defense mechanism? What is displacement?
correct answers Immature. A patient redirects emotions from the person or object that's
causing the emotions (e.g., wife), but who it woudl be completely unacceptable to direct
, those emotions toward, to a more acceptable, but still inappropriate, person or object
(e.g., a wall or a vase).
Is sublimation a mature or immature defense mechanism? How does it work? correct
answers Mature. Unacceptable drives are redirected toward completely acceptable
targets. (Workout hard if you're angry)
Is projection a mature or immature defense mechanism? What is it? correct answers
Immature. Unacceptable or personally disagreeable impulses are attributed to others;
e.g., a student who wants to cheat on a test accuses his classmates of cheating. Or the
gayness thing
Is reaction formation immature or mature defense mechanism? what is it? correct
answers immature, where unacceptable feeligns are IGNORED and the opposite
sentiment is adopted (forced). man who's mad at his wife instead compliments her
dress
Is splitting a mature or immature defense mechanism? what is it? correct answers
immature. frequently employed by patients with borderline personality disorder,
everything is either "good or bad."
What do you do if you suspect child abuse? Ask the parents or call child protective
services? correct answers Call Child Protective Services immediately!
Psychologically speaking, what phenomenon is "white coat syndrome" associated with?
correct answers Classical Conditioning. In classical conditioning, a reflexive response
normally elicited by an unconditioned stimulus becomes evocable by a second, formally
neutral (conditioned) stimulus.
What three things can patients with bulimia develop (hint: one isn't weight loss because
bulimia doesn't work.)? correct answers (1) bilateral partodi gland enlargement
(2) erosion of tooth enamel*
(3) irregular menses
What is the pulmonary capillary wedge pressure and what does it indirectly measure?
correct answers Pressure in the pulmonary artey distal to the point of its occlusion by an
inflated intravascular balloon.
Since there's no significant blood flow towards the left atrium (LA) beyong this point of
occlusion, the pressure at the tip of the "wedged" pulmonary artery catheter is an
indirect measurement of LA Pressure.
What would we expect, in a normal patient, the relationship to be between LA and LV
pressure during diastole? correct answers We would expect them to be nearly equale
(both <12) since the open mitral valve offers minimal resistance to flow between the 2
chambers
