1/6/20, 3:22:45 PM
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New File:
Old File:
First Aid for the USMLE Step 1 2020, Thirtieth
FA 2019.pdf
versus edition-1.pdf
32 pages (293.11 MB)
34 pages (109.99 MB)
1/5/20, 12:57:57 PM
1/5/20, 12:52:18 PM
BY u/verified-idiot
To the only girl i've ever loved, to soufia.
BLUE new in FA 2020
YELLOW text of FA 2019 was edited; the note box next to the yellow highlight will show
the difference between them the old text and the new text of FA 2020
Some pages might look scary! because of note boxes and highlighting , but it is not, my
recommendation for you is to study your book and after than look for the new stuff and
edits.. I DONT recommend comparing while you are studying since it will consume your
time.
Go to First Change (page 1)
file://NoURLProvided[1/6/20, 3:22:45 PM]
,HIGH-YIELD SYSTEMS
Renal
“But I know all about love already. I know precious little still about ` Embryology 578
kidneys.”
—Aldous Huxley, Antic Hay ` Anatomy 580
“This too shall pass. Just like a kidney stone.” ` Physiology 581
—Hunter Madsen
` Pathology 594
“I drink too much. The last time I gave a urine sample it had an olive
in it.” ` Pharmacology 607
—Rodney Dangerfield
Being able to understand and apply renal physiology will be critical
for the exam. Important topics include electrolyte disorders, acid-base
derangements, glomerular disorders (including histopathology), acute
and chronic kidney disease, urine casts, diuretics, ACE inhibitors,
and AT-II receptor blockers. Renal anomalies associated with various
congenital defects are also high-yield associations to think about when
evaluating pediatric vignettes.
577
,578 SEC TION III RENAL `R̀ENAL—EMBRYOLOGY
``
RENAL—EMBRYOLOGY
Kidney embryology Pronephros—week 4; then degenerates.
Mesonephros—functions as interim kidney for
Degenerated
1st trimester; later contributes to male genital pronephros
system.
Metanephros—permanent; first appears in 5th
week of gestation; nephrogenesis continues Mesonephros
through weeks 32–36 of gestation. Mesonephric
Ureteric bud (metanephric diverticulum)— Metanephric
duct
derived from caudal end of mesonephric mesenchyme
duct; gives rise to ureter, pelvises, calyces, Metanephros
collecting ducts; fully canalized by 10th Ureteric bud
week Urogenital sinus
Metanephric mesenchyme (ie, metanephric
blastema)—ureteric bud interacts with this
tissue; interaction induces differentiation
and formation of glomerulus through to
distal convoluted tubule (DCT)
Aberrant interaction between these 2
tissues may result in several congenital
malformations of the kidney (eg, renal
agenesis, multicystic dysplastic kidney)
Ureteropelvic junction—last to canalize
congenital obstruction. Most common
cause of prenatal hydronephrosis. Detected by
prenatal ultrasound.
Potter sequence Oligohydramnios compression of Babies who can’t “Pee” in utero develop Potter
(syndrome) developing fetus limb deformities, sequence.
A facial anomalies (eg, low-set ears and POTTER sequence associated with:
retrognathia A , flattened nose), compression Pulmonary hypoplasia
of chest and lack of amniotic fluid aspiration Oligohydramnios (trigger)
into fetal lungs pulmonary hypoplasia Twisted face
(cause of death). Twisted skin
Causes include ARPKD, obstructive uropathy Extremity defects
(eg, posterior urethral valves), bilateral renal Renal failure (in utero)
agenesis, chronic placental insufficiency.
, RENAL `R̀ENAL—EMBRYOLOGY SEC TION III 579
Horseshoe kidney Inferior poles of both kidneys fuse A
Aorta abnormally A . As they ascend from pelvis
Horseshoe
kidney during fetal development, horseshoe kidneys
Renal artery
get trapped under inferior mesenteric
artery and remain low in the abdomen.
Kidneys function normally. Associated with
hydronephrosis (eg, ureteropelvic junction
Ureter Inferior
mesenteric obstruction), renal stones, infection, risk of
artery
renal cancer.
Higher incidence in chromosomal aneuploidy
(eg, Turner syndrome, trisomies 13, 18, 21).
Congenital solitary Condition of being born with only one functioning kidney. Majority asymptomatic with
functioning kidney compensatory hypertrophy of contralateral kidney, but anomalies in contralateral kidney are
common. Often diagnosed prenatally via ultrasound.
Unilateral renal Ureteric bud fails to develop and induce differentiation of metanephric mesenchyme complete
agenesis absence of kidney and ureter.
Multicystic dysplastic Ureteric bud fails to induce differentiation of metanephric mesenchyme nonfunctional kidney
kidney consisting of cysts and connective tissue. Predominantly nonhereditary and usually unilateral;
bilateral leads to Potter sequence.
Duplex collecting Bifurcation of ureteric bud before it enters the metanephric blastema creates a Y-shaped bifid
system ureter. Duplex collecting system can alternatively occur through two ureteric buds reaching and
interacting with metanephric blastema. Strongly associated with vesicoureteral reflux and/or
ureteral obstruction, risk for UTIs.
Posterior urethral Membrane remnant in the posterior urethra
valves in males; its persistence can lead to urethral
Kidney Hydronephrosis
obstruction. Can be diagnosed prenatally by
bilateral hydronephrosis and dilated or thick- Dilated ureter
Ureter
walled bladder on ultrasound. Most common Urinary reflux
cause of bladder outlet obstruction in male
infants. Associated with oligohydramnios in Bladder Distended bladder
cases of severe obstruction.
Urethra Urethra obstructed
by posterior urethral
membrane
Normal Posterior
urethral valves
Compare Results
New File:
Old File:
First Aid for the USMLE Step 1 2020, Thirtieth
FA 2019.pdf
versus edition-1.pdf
32 pages (293.11 MB)
34 pages (109.99 MB)
1/5/20, 12:57:57 PM
1/5/20, 12:52:18 PM
BY u/verified-idiot
To the only girl i've ever loved, to soufia.
BLUE new in FA 2020
YELLOW text of FA 2019 was edited; the note box next to the yellow highlight will show
the difference between them the old text and the new text of FA 2020
Some pages might look scary! because of note boxes and highlighting , but it is not, my
recommendation for you is to study your book and after than look for the new stuff and
edits.. I DONT recommend comparing while you are studying since it will consume your
time.
Go to First Change (page 1)
file://NoURLProvided[1/6/20, 3:22:45 PM]
,HIGH-YIELD SYSTEMS
Renal
“But I know all about love already. I know precious little still about ` Embryology 578
kidneys.”
—Aldous Huxley, Antic Hay ` Anatomy 580
“This too shall pass. Just like a kidney stone.” ` Physiology 581
—Hunter Madsen
` Pathology 594
“I drink too much. The last time I gave a urine sample it had an olive
in it.” ` Pharmacology 607
—Rodney Dangerfield
Being able to understand and apply renal physiology will be critical
for the exam. Important topics include electrolyte disorders, acid-base
derangements, glomerular disorders (including histopathology), acute
and chronic kidney disease, urine casts, diuretics, ACE inhibitors,
and AT-II receptor blockers. Renal anomalies associated with various
congenital defects are also high-yield associations to think about when
evaluating pediatric vignettes.
577
,578 SEC TION III RENAL `R̀ENAL—EMBRYOLOGY
``
RENAL—EMBRYOLOGY
Kidney embryology Pronephros—week 4; then degenerates.
Mesonephros—functions as interim kidney for
Degenerated
1st trimester; later contributes to male genital pronephros
system.
Metanephros—permanent; first appears in 5th
week of gestation; nephrogenesis continues Mesonephros
through weeks 32–36 of gestation. Mesonephric
Ureteric bud (metanephric diverticulum)— Metanephric
duct
derived from caudal end of mesonephric mesenchyme
duct; gives rise to ureter, pelvises, calyces, Metanephros
collecting ducts; fully canalized by 10th Ureteric bud
week Urogenital sinus
Metanephric mesenchyme (ie, metanephric
blastema)—ureteric bud interacts with this
tissue; interaction induces differentiation
and formation of glomerulus through to
distal convoluted tubule (DCT)
Aberrant interaction between these 2
tissues may result in several congenital
malformations of the kidney (eg, renal
agenesis, multicystic dysplastic kidney)
Ureteropelvic junction—last to canalize
congenital obstruction. Most common
cause of prenatal hydronephrosis. Detected by
prenatal ultrasound.
Potter sequence Oligohydramnios compression of Babies who can’t “Pee” in utero develop Potter
(syndrome) developing fetus limb deformities, sequence.
A facial anomalies (eg, low-set ears and POTTER sequence associated with:
retrognathia A , flattened nose), compression Pulmonary hypoplasia
of chest and lack of amniotic fluid aspiration Oligohydramnios (trigger)
into fetal lungs pulmonary hypoplasia Twisted face
(cause of death). Twisted skin
Causes include ARPKD, obstructive uropathy Extremity defects
(eg, posterior urethral valves), bilateral renal Renal failure (in utero)
agenesis, chronic placental insufficiency.
, RENAL `R̀ENAL—EMBRYOLOGY SEC TION III 579
Horseshoe kidney Inferior poles of both kidneys fuse A
Aorta abnormally A . As they ascend from pelvis
Horseshoe
kidney during fetal development, horseshoe kidneys
Renal artery
get trapped under inferior mesenteric
artery and remain low in the abdomen.
Kidneys function normally. Associated with
hydronephrosis (eg, ureteropelvic junction
Ureter Inferior
mesenteric obstruction), renal stones, infection, risk of
artery
renal cancer.
Higher incidence in chromosomal aneuploidy
(eg, Turner syndrome, trisomies 13, 18, 21).
Congenital solitary Condition of being born with only one functioning kidney. Majority asymptomatic with
functioning kidney compensatory hypertrophy of contralateral kidney, but anomalies in contralateral kidney are
common. Often diagnosed prenatally via ultrasound.
Unilateral renal Ureteric bud fails to develop and induce differentiation of metanephric mesenchyme complete
agenesis absence of kidney and ureter.
Multicystic dysplastic Ureteric bud fails to induce differentiation of metanephric mesenchyme nonfunctional kidney
kidney consisting of cysts and connective tissue. Predominantly nonhereditary and usually unilateral;
bilateral leads to Potter sequence.
Duplex collecting Bifurcation of ureteric bud before it enters the metanephric blastema creates a Y-shaped bifid
system ureter. Duplex collecting system can alternatively occur through two ureteric buds reaching and
interacting with metanephric blastema. Strongly associated with vesicoureteral reflux and/or
ureteral obstruction, risk for UTIs.
Posterior urethral Membrane remnant in the posterior urethra
valves in males; its persistence can lead to urethral
Kidney Hydronephrosis
obstruction. Can be diagnosed prenatally by
bilateral hydronephrosis and dilated or thick- Dilated ureter
Ureter
walled bladder on ultrasound. Most common Urinary reflux
cause of bladder outlet obstruction in male
infants. Associated with oligohydramnios in Bladder Distended bladder
cases of severe obstruction.
Urethra Urethra obstructed
by posterior urethral
membrane
Normal Posterior
urethral valves
