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Test your basic knowledge |
USMLE Embryo
Start Test
Study First
Subjects
:
health-sciences
,
usmle
Instructions:
Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can
study here
.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.
This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Which branchial derivative accounts for the posterior 2/3 of the tongue?
Prenatal and perinatal
Scrotum; labia majora
No organ in each; agenesis no primordial tissue
3rd and 4th arches
2. What is DiGeorge syndrome and What does it result in?
Dorsal; faulty positioning of genital tubercle
Aberrant development of 3rd and 4th pouches; t cell def (thymic aplasia) - hypocalcemia (failure of parathyroid development) - CF and CV defects
...
Amniotic epithelium
3. What causes persistent Truncus Arteriosus? What does it result in?
Surface ectoderm
Skewed development of AP septum
Prostaglandins
Partial AP septum development; one large vessel leaves the heart - Right to left shunt
4. By what week is there fetal movement?
Week 4
Metencephalon; cerebellum
Tongue
Week 8
5. From What embryonic layer does the retina arise?
When the AP septum meets and fuses with the muscular ventricular septum to form membranous intraventricular septum - closing interventricular foramen
Neuroectoderm
Cleft lip/palate
Failure of the urachus to obliterate
6. What is omphalocele? In What trisomies is it seen?
Thickened ectoderm at end of each developing limb
Persistance of herniation of abdominal contents into umbilical cord covered by peritoneum; 13 - 18
Midgut; 10th week
Lacunae in between the chorionic villi
7. From what region does the midbrain form from?
Wolffian; mullerian
Mesencephalon
...
Hypospadias
8. Where is the decidua basalis derived from?
Endometrium
Prenatal and perinatal
Neural plate; closes by week 4
Membrane - all 3 from 1st appartus
9. What teratogen can cause inhibition of intestinal folate absorption and thus neural tube defects?
Respiratory distress syndrome
Apical ectodermal ridge
Valproate acid
Cleft lip/palate
10. From where did a branchial cleft cyst arise if it found?
Found in lateral neck; from no obliteration of 2-4th clefts
First branchial pouch
Post. sup wall; luteal phase
Mesencephalon
11. What separated myometrium of the uterus from the blastocyst?
Decidual basalis
Fetal kidney; fetal swallows - absorbs - and then removed from placental blood
secondary palate
Week 4
12. What gene is produced in the zone of polarizing activity?
Sonic Hedgehog
Neural crest cells
Mesoderm
DiGeorge
13. What does the midgut form? hindgut?
Duodenum to transverse colon; distal transverse colon to rectum
Tunica vaginalis not fully fused
Urogenital sinus; wolffian duct; mullerian duct; urogenital sinus; wolffian duct; wolffian duct; mullerian; mullerian
Rhombencephalon
14. What artery is derived branchial (aortic) arch 6?
Foregut; dorsal mesentery (mesodermal)
Pulm art (prox) and ductus arteriosus
Found in lateral neck; from no obliteration of 2-4th clefts
Obliterated; forms tunica vaginalis
15. From What embryonic layer does the neurohypophysis arise?
Vascular accident intra uterine; apple peel atresia
Neuroectoderm
Polyhydramnios - Down syndrome - Esophageal/duodenal atresia - Imperforate anus - Meckel diverticulum
Neural crest cells
16. How is amniontic fluid excreted? How is amniotic fluid resorped?
Neuroectoderm
Metencephalon; cerebellum
Failure of the urachus to obliterate; outpouching of the bladder
Fetal kidney; fetal swallows - absorbs - and then removed from placental blood
17. what separates the atria from the ventricles?
hypertrophy
Synctiotrophoblast; outer; no
Week 4
Endocardial cushions
18. what structures are the derivatives of the neural crest cells in branchial arches?
Bone/cartilage and nerves
Decidual basalis
Midgut; 10th week
Neuroectoderm
19. What layer is the epiblast? hypoblast?
Female; paramesonephric; mesonephric
Fallopian tube - uterus - upper 1/3 of vagina
SRY gene on Y chromosomes; sertoli and leydi; MIF and androgens; suppression of paramesonephric ducts and dev. of mesonephric (all respectively)
Ectoderm; endoderm
20. From What embryonic layer is the vagina from? testes? ovaries?
Mesoderm
Week 3-8
Week 4
Found in lateral neck; from no obliteration of 2-4th clefts
21. What is the kidney that functions at the interim kidney in the 1st trimester? What does it later contribute to?
Cranio - caudal; segmental
Mesonephros; male genital system
SRY gene on Y chromosomes; sertoli and leydi; MIF and androgens; suppression of paramesonephric ducts and dev. of mesonephric (all respectively)
Epispadias
22. How do AV canals form?
Surface ectoderm
From endocardial cushions (ventral and dorsal meet each other)
Day 6; maintains corpus luteum; 1st trimester
Annular pancrease
23. From What embryonic layer are the pia and arachnoid from?
DiGeorge
4th week
Caused by compression on trocheal nerve - causes vertical gaze paralysis (associated with arnold chiari)
Neural crest cells
24. What embryologic structure provides the aorticpulmonary septum?
Neural crest cells
Neural crest migration - they then cause spiral
Increased AFP and acetycholinesterase (not ACh!) in CSF
Nutrient and gas exchange
25. What teratogen can cause IUGR and ADHD in a fetus? what else can this teratogen cause?
Nicotine; preterm labor
Uretopelvis; most common site for obstruction (hydronephrosis) in fetus
Endoderm
Surface ectoderm
26. What does the vitelline duct connect? What is it also known as? when should it obliterate?
Mid gut to yolk sac; omphalomesenteric duct; 7th week
Neuroectoderm
Mesencephalon
Cleft lip/palate
27. Cleft lip is a failure of fusion of ________ and ______.
Maxillary and medial nasal processes
1st branchial arch
2; 1
Myelencephalon
28. From what region of the brain does the lateral ventricles and the 3rd ventricle form?
Thyroglossal duct cysts will move with swallowing while persistent cervical sinuses in lateral neck wont
Thickened ectoderm at end of each developing limb
Prosencephalon
Deoxygenated blood; fetal internal iliac arteries to placenta
29. From What embryonic layer do the ependymal cells arise?
From teh lung;blood from IVC in RA to LA; fossa ovalis
Neuroectoderm
Neural crest cells
monoamniotic
30. From What embryonic layer are the dorsal root and celiac ganglion from?
Neural crest cells
Membrane - all 3 from 1st appartus
No organ in each; agenesis no primordial tissue
Endoderm
31. What germ layer correlates with the branchial pouches?
3rd and 4th arches
Endoderm
mesoderm
When the AP septum meets and fuses with the muscular ventricular septum to form membranous intraventricular septum - closing interventricular foramen
32. What are the three results of having pathology in the aorticopulmonary septum?
Week 4
Transposition of great vessels (failure to spiral)- right to left shunt; tetralogy of Fallout (right to left shunt caused by skewed development of septum); persistent TA (partial septum development - also right to left shunt)
Alkylating agents
Vascular accident intra uterine; apple peel atresia
33. What is the most common subtype of tracheoesophageal fistula? name some symptoms (hint: O2 levels - feeding - stomach on CXR - - amnios? - NG tube? - respiratory infection? )
Ampulla
Blind upper esophagus with lower esophagus connected to trachea; cyanosis - choking and vomiting with feeding; air bubble on CXR; polyhydramnios; failure to pass NG tube; pneumonitis
1st cleft/groove (Ectoderm)
2nd; 2nd
34. Which CN accounts for the anterior 2/3 of the tongues sensation and pain? how about taste?
V3; VII
Neuroectoderm
3 -4 -6
Arnold chiari; syringomyelia
35. What is the mnueomonic for the mesodermal defects? What does it stand for?
Found in lateral neck; from no obliteration of 2-4th clefts
Midgut; 10th week
VACTERL- vertebral defect - anal atresia - cardiac defects - tracheo - esophageal fistula - renal defects - limb defects
not covered
36. What day is the chorion formed?
Endoderm
septum primum and/or secundum
3
VSD
37. In both meningocele and myelomeningocele the dura...
is no longer intact
septum primum and/or secundum
V3; VII
Pronephros - mesonephros - metanephros; pronephros; most cranially
38. At what week does the fetus look like a baby?
Germinal matrix hemorrhage
Mesoderm
Week 8
Failure of the urachus to obliterate; outpouching of the bladder
39. What does DHT turn the labioscrotal swelling into? estrogen?
Synctiotrophoblast; outer; no
Scrotum; labia majora
Epiblast
Arnold Chiari and Dandy Walker; Arnold Chiari; Dandy Walker; Arnold Chiari
40. What is the fate of the cervical sinuses that develop from the 2nd -4th branchial grooves?
Obliterated
Mesoderm
Obliterated; forms tunica vaginalis
Skewed development of AP septum
41. Which branchial arch derivative is obliterated?
Week 10-12; end of 1st trimester
5th
StyloPharyngeus
Upper 1/3; urogenital sinus
42. What role does the placenta have?
Yolk sac; 3rd week
Nutrient and gas exchange
Surface ectoderm
Tunica vaginalis not fully fused
43. The notochord is...
Yolk sac; 3rd week
Transposition of great vessels (failure to spiral)- right to left shunt; tetralogy of Fallout (right to left shunt caused by skewed development of septum); persistent TA (partial septum development - also right to left shunt)
mesoderm
Muscles and arteries
44. From where does the ureteric bud arise? What does it give rise to?
Upper 1/3; urogenital sinus
Endoderm
The caudal end mesonephros; the ureter - pelvis - calyces - collecting ducts
Endoderm
45. From what branchial derivative do the parafollicular cells arise?
Endoderm
4th/5th branchial pouches
monoamniotic
Thalidomide; nausea
46. What causes urine discharge from the umbilicus?
Failure of the urachus to obliterate
Lithium; valve leaflets attach to domain down low in RV- 'atrialized RV'
Mesoderm
Fluid filled syrinx causes expansion and degeneration of cord tracts
47. what muscles are derived from branchial arch 1?
Muscles of Mastication: Temporalis - masseter - Lateral and Medila pterygoids - Mylohyoid - anterior belly of the digastric - tensor tympani - tensor veli palatini; ant 2/3 of tongue
Week 3-8
Rhombencephalon
Neuroectoderm
48. How does annular pancreas present in children?
Truncus arteriosus; pulmonary trunk
Foregut; dorsal mesentery (mesodermal)
Decreased separation of hemispheres across midline; cyclopia
Gastric outlet obstruction (bilious vomiting - feeding intolerance - abdominal distention)
49. Where is erythropoeisis in the weeks 3-8 of fetal development? Where does it occur after that? until when?
Week 4
Yolk sac; liver (weeks 6-30) and spleen (9-28 weeks)
Ectoderm
Midgut; 10th week
50. From What embryonic layer does bone arise ?
Week 8
Surface ectoderm
Medial palatine processes
Mesoderm