Test your basic knowledge |

USMLE Embryo

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. How is amniontic fluid excreted? How is amniotic fluid resorped?
Lithium
8
When the AP septum meets and fuses with the muscular ventricular septum to form membranous intraventricular septum - closing interventricular foramen
Fetal kidney; fetal swallows - absorbs - and then removed from placental blood

2. How do adults with annular pancreas present? and At What age?
StyloPharyngeus
20-50yrs - Abdominal pain - Postprandial fullness - Nausea - Peptic ulcers - Pancreatitis - Rarely - biliary obstruction
Medial palatine processes
Dorsal ventral axis

3. From What embryonic layer are the melanocytes from?
Endoderm
Physiologic incomplete muscular ventricular septum
Temporary cervical sinus
Neural crest cells

4. What part of the fetal comp of the placenta secretes hCG? is this part on the inner or outer layer of the chorionic villi? does it make cells?
Right common cardinal vein and right anterior cardinal vein
Dorsal ventral axis
VSD
Synctiotrophoblast; outer; no

5. What does DHT turn the labioscrotal swelling into? estrogen?
Neural crest migration - they then cause spiral
Scrotum; labia majora
Medial palatine processes
ACE inhibitors - HCTZ

6. From What embryonic layer are the serous linings of the body cavities from? for ex - peritoneum?
Stapedius and hyoid artery
...
2nd; 2nd
Polyhydramnios

7. _____________is common in 1st born males
2nd; 2nd
Bone/cartilage and nerves
pyloric stenosis
Increased AFP and acetycholinesterase (not ACh!) in CSF

8. In both meningocele and myelomeningocele the dura...
Neural crest cells
Urachus/median umbilical ligament; bladder and yolk sac
is no longer intact
1st cleft/groove (Ectoderm)

9. What teratogens can cause renal damage in the fetus?
Fallopian tube - uterus - upper 1/3 of vagina
ACE inhibitors - HCTZ
All intrinsic muscles of larynx except cricothyroid; CN X (recurrent laryngeal nerve - speaking)
Umbilical - midgut herniates through umbilical ring; SMA

10. From where does the ureteric bud arise? What does it give rise to?
The caudal end mesonephros; the ureter - pelvis - calyces - collecting ducts
Scrotum; labia majora
Mesonephros; male genital system
Endoderm

11. From What embryonic layer does the spinal cord arise?
Neuroectoderm
3rd; proximal part of the internal carotid artery
Female; paramesonephric; mesonephric
Midgut; 10th week

12. What is the neural plate and From what does it form?
Polyhydramnios - Down syndrome - Esophageal/duodenal atresia - Imperforate anus - Meckel diverticulum
Partial AP septum development; one large vessel leaves the heart - Right to left shunt
Mesoderm
Ectoderm

13. What teratogen can cause IUGR and ADHD in a fetus? what else can this teratogen cause?
Caused by compression on trocheal nerve - causes vertical gaze paralysis (associated with arnold chiari)
Mesoderm
External auditory meatus
Nicotine; preterm labor

14. From What embryonic layer are the dorsal root and celiac ganglion from?
Neural crest cells
Partial closure of vitelline duct so that the patent portion is attached to ileum; ectopic gastric mucosa; melena and periumbilical pain
Prosencephalon - mesencephalon - rhombencephalon
After; extrinsic

15. From What embryonic layer are the schwann cells from ?
Neural crest cells
Valproate acid
Surface ectoderm
After; extrinsic

16. How does annular pancreas present in children?
Endometrium
4th week
Gastric outlet obstruction (bilious vomiting - feeding intolerance - abdominal distention)
Mesoderm

17. What two things cause VACTERL syndrome?
OCPS and maternal diabetes
Sperm plus egg
Dorsal ventral axis
Epiblast

18. What do membranous interventricular septal defect cause? What does this lead to?
Neural crest cells
Initial left to right shunting - then switches
VACTERL- vertebral defect - anal atresia - cardiac defects - tracheo - esophageal fistula - renal defects - limb defects
Arches 3 and 4

19. What is the mnueomonic for the mesodermal defects? What does it stand for?
VACTERL- vertebral defect - anal atresia - cardiac defects - tracheo - esophageal fistula - renal defects - limb defects
Aminoglycosides
Apical ectodermal ridge
Day 6; maintains corpus luteum; 1st trimester

20. During what week does the heart begin to beat?
Week 4
Synctiotrophoblast; outer; no
Hepatic circulation; ligamentum venosum
Glans penis and corpus cavernosum and spongiosum; glans clitoris and vestibular bulbs

21. Name two endocardial cushion defects.
8
Neuroectoderm
Ebsteins anomaly; tricuspid atresia
Surface ectoderm

22. what muscles are derived from branchial arch 4? CN?
Prosencephalon
Bones - cartilage - and nerves
Most pharyngeal constrictors - Cricothyroid - levator veli palatini; CN X (superior laryngeal branch - swallowing)
Fallopian tube - uterus - upper 1/3 of vagina

23. What are the aspects of fetal alcohol syndrome?
Mental retardation - holoprosencephaly - facial features - fistulas
Thalidomide; nausea
Neural crest cells
XII

24. What axis does the alar plate form? what neural system does it become?
4th week
can make cells
Primitive ventricle
Dorsal; sensory

25. From What embryonic layer are the cardiovascular - lymphatics and blood from?
2nd pouch
Mesoderm
8
Failure of the urachus to obliterate; outpouching of the bladder

26. What is DiGeorge syndrome and What does it result in?
Aberrant development of 3rd and 4th pouches; t cell def (thymic aplasia) - hypocalcemia (failure of parathyroid development) - CF and CV defects
Meckels cartilage: mandible - malleus - INCUS - sphenoMandibular ligament; CN V2 and V3
Week 3-8
Sonic Hedgehog

27. In what chromosomal disorder is horseshoe kidney commonly seen? what poles of the kidneys fuse?
Mesoderm; 3 week
Turners; inferior
1st
not covered

28. Does malformation occur during or after the embryonic period? is it due to an extrinsic or intrinsic disruption?
During; instrinsic
Mullerian inhibitory factor from Sertoli cells; increased androgen from Leydig cells
Muscles of facial expression - stapedius - stylohyoid - posterior belly of the digastric
Umbilical - midgut herniates through umbilical ring; SMA

29. Which branchial apparatus derivative makes the tympanic membrane of the ear?
Arnold Chiari and Dandy Walker; Arnold Chiari; Dandy Walker; Arnold Chiari
Membrane - all 3 from 1st appartus
Arches 3 and 4
Female; paramesonephric; mesonephric

30. What part of the gut rotates around the SMA? and At what point?
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)
Midgut; 10th week
Ionizing
Thyroid - cricoid - arytenoids - corniculate cuneiform

31. Which branchial derivative accounts for the posterior 2/3 of the tongue?
Cytotrophoblast
Aortic arch and prox part of subclavian
3rd and 4th arches
Thickened ectoderm at end of each developing limb

32. How do AV canals form?
Persistent connection between amniotic cavity and spinal canal; low folic acid
From endocardial cushions (ventral and dorsal meet each other)
Neuroectoderm
LH

33. what other facial defect other than cyclopia is associated with holoprosencephaly?
Thyroid - cricoid - arytenoids - corniculate cuneiform
Cleft lip/palate
2nd pouch
Hemorrhage - bone deformities

34. What is the primitive streak? From what layer does it form?
Found in lateral neck; from no obliteration of 2-4th clefts
Mesoderm; epiblast
Rhombencephalon
Endocardial cushions

35. From What do the embryoblast and trophoblast form from? What does the embryoblast split into? the trophoblast?
Blastocyst; epiblast and hypoblast; synctiotrophoblast and cytotrophoblast
4th/5th branchial pouches
All intrinsic muscles of larynx except cricothyroid; CN X (recurrent laryngeal nerve - speaking)
No more umbilical circulation emptying into RA

36. From What embryonic layer does the lens of the eye arise?
Prosencephalon
Surface ectoderm
Pulm art (prox) and ductus arteriosus
Sonic Hedgehog

37. What causes a large posterior fossa in a dandy walker malformation? What is found in this fossa?
Absent cerebellar vermis; cystic enlargement of 4th ventricle
Pataus; fetal alcohol syndrome
Physiologic incomplete muscular ventricular septum
Hepatic circulation; ligamentum venosum

38. From What embryonic layer does the epidermis arise?
Surface ectoderm
secondary palate
Hypertrophy of muscularis externis of pylorus; surgical incision
mesodermal

39. From What embryonic layer does the skin dermis arise?
Failure to spiral (aorta coming out of RV and PA coming out of left ventricle)- two completely separate systems
Cytotrophoblast
Ectoderm - mesoderm - endoderm; epiblast - primitive streak - hypoblast; week 3
Mesoderm

40. What is a teratogen that causes Ebsteins anomaly? What is ebsteins anomaly?

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

41. Where is Wnt 7 gene produced?
Primitive atrium
Failure to spiral (aorta coming out of RV and PA coming out of left ventricle)- two completely separate systems
Apical ectodermal ridge
...

42. What role does the placenta have?
Neural crest cells
Neuroectoderm
Folate antagonists
Nutrient and gas exchange

43. what separates the atria from the ventricles?
Endocardial cushions
Week 10-12; end of 1st trimester
Primitive atrium
Apical ectodermal ridge; limb lengthening; stimulates mitosis of underlying mesoderm

44. From which branchial derivative does the anterior 2/3 of the tongue develop?
Week 4; week 3
Ectoderm
1st branchial arch
Failure to spiral (aorta coming out of RV and PA coming out of left ventricle)- two completely separate systems

45. What teratogens can cause CN VIII toxicity in the fetus?
Mental retardation - holoprosencephaly - facial features - fistulas
Aminoglycosides
Day 6; with implantation
Bulbourethral glands (of Cowper) and Prostate gland; greater vestibular glands (of Bartholin) and Urethral and paraurethral glands (of Skene)

46. From What embryonic layer does the neurohypophysis arise?
Ectoderm
Mullerian inhibitory factor from Sertoli cells; increased androgen from Leydig cells
Neuroectoderm
Deformation

47. what chemo drugs can cause neural tube defects in the fetus?
Folate antagonists
...
IMA
Ring of pancreatic tissue can cause duodenal narrowing; ventral pancreatic bud abnormally encircles 2nd part of duodenum

48. From what are the umbilical arteries and veins derived from?
Found in lateral neck; from no obliteration of 2-4th clefts
Allantois
Ventral; failure of urogenital folds to close
Surface ectoderm

49. From What embryonic layer is the eustachian tube from?
Neuroectoderm
Mesoderm
Found in lateral neck; from no obliteration of 2-4th clefts
Bulbos Cordis; right ventricle entirely

50. What three layers form during gastrulation? From What do they form? and what week does gastrulation occur?
Female; paramesonephric; mesonephric
Neural crest cells
Ectoderm - mesoderm - endoderm; epiblast - primitive streak - hypoblast; week 3
Lacunae in between the chorionic villi