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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. What is perinauds syndrome?
Grooves/clefts; arches; pouches
Caused by compression on trocheal nerve - causes vertical gaze paralysis (associated with arnold chiari)
Thyroid - cricoid - arytenoids - corniculate cuneiform
...
2. What causes the transposition of the great vessels? What does it result in?
Bulbos Cordis; right ventricle entirely
Endoderm
28 week onward
Failure to spiral (aorta coming out of RV and PA coming out of left ventricle)- two completely separate systems
3. From What embryonic layer does the thyroid follicular cells arise?
Base of limbs in the zone of polarizing activity; ant - post
Arnold Chiari and Dandy Walker; Arnold Chiari; Dandy Walker; Arnold Chiari
Post. sup wall; luteal phase
Endoderm
4. what bone/cartilage are derived from branchial arch 4-6?
Found in lateral neck; from no obliteration of 2-4th clefts
Thyroid - cricoid - arytenoids - corniculate cuneiform
Decreased separation of hemispheres across midline; cyclopia
Neural crest cells
5. What is used to keep the PDA open?
Ectoderm
Prostaglandins
Umbilical - midgut herniates through umbilical ring; SMA
Urachus/median umbilical ligament; bladder and yolk sac
6. Where is the mothers blood located in the placenta?
Blastocyst; epiblast and hypoblast; synctiotrophoblast and cytotrophoblast
Lacunae in between the chorionic villi
The caudal end mesonephros; the ureter - pelvis - calyces - collecting ducts
OCPS and maternal diabetes
7. Where does the blastocyst implant in the uterus? During what phase of the menstrual cycle?
Ectoderm
Post. sup wall; luteal phase
Neuroectoderm
LH
8. On what side is the abnormal opening in epispadias? What causes it?
Neural crest development; MEN 2A (pheo - PTH tumor - parafollicular cell tumor)
Dorsal; faulty positioning of genital tubercle
Rostral fold closure ; lateral fold closure; lateral fold closure; caudal fold closure
Oligohydramnios
9. What axis does the basal plate form? what neural system does it become?
Ventral ; motor
Failure to recanalize; 21
Fetal kidney; fetal swallows - absorbs - and then removed from placental blood
XII
10. What causes the increase in left atrial pressure to close the fossa ovale?
Decreased pulmonary resistance in the pulmonary vasculature
Amniotic epithelium
Week 3-8
All intrinsic muscles of larynx except cricothyroid; CN X (recurrent laryngeal nerve - speaking)
11. In anencephaly you see...
Endoderm
Surface ectoderm
elevated AFP
Pharynx to duodenum; duodenum to transverse colon; distal transverse colon to rectum
12. The spinal cord is made from...
Lacunae in between the chorionic villi
T neuroectoderm
Mesoderm
Endoderm - floor of primitive pharynx
13. What causes the degeneration of the spinal cord in syringomelia?
1st arch neural crest fails to migrate --> mandibular hypoplasia - facial abnormalities (cleft palate - decreased slanting of palpebral fissures)
Neural crest cells
Obliterated
Fluid filled syrinx causes expansion and degeneration of cord tracts
14. From where does pons form from? what else forms from there?
Lacunae in between the chorionic villi
5th
Neuroectoderm
Metencephalon; cerebellum
15. What does the mullerian duct develop into? wollffian?
Fallopian tube - uterus - upper 1/3 of vagina
Lots - cleft palate/lip
Respiratory distress syndrome
Lacunae in between the chorionic villi
16. How is amniontic fluid excreted? How is amniotic fluid resorped?
Foramen cecum and terminal sulus
Week 10-12; end of 1st trimester
Stapedius and hyoid artery
Fetal kidney; fetal swallows - absorbs - and then removed from placental blood
17. What are the neural crest cells and where do they come form? where do they go?
Cleft lip/palate
They are the edge of neural plate folding; all over the body
monoamniotic
Failure to recanalize; 21
18. What is jejunal - ileal - colonic atresia usually due to? What do you see on x ray?
Mesoderm; 3 week
Vascular accident intra uterine; apple peel atresia
Neuroectoderm
VSD
19. What does DHT turn the genital tubercle into? estrogen?
Obliterated
Stapedius and hyoid artery
Glans penis and corpus cavernosum and spongiosum; glans clitoris and vestibular bulbs
Neuroectoderm
20. What embryonic structure gives rise to the ascending aorta? what else does it give rise to?
Rostral fold closure ; lateral fold closure; lateral fold closure; caudal fold closure
A vitelline fistula - failure of vitelline duct to close
Endoderm
Truncus arteriosus; pulmonary trunk
21. in hypospadias - on which side is the abnormal opening? What causes it?
Week 8
Ventral; failure of urogenital folds to close
Respiratory distress syndrome
Fetal kidney; fetal swallows - absorbs - and then removed from placental blood
22. From What embryonic layer does the parathyroid arise ?
6-30
Common carotid and internal carotid
Endoderm
Endocardial cushions
23. What part of the gut rotates around the SMA? and At what point?
Right common cardinal vein and right anterior cardinal vein
Week 8
Midgut; 10th week
Obliterated; forms tunica vaginalis
24. From What embryonic layer does the sensory organs of the ear arise?
Surface ectoderm
Ectoderm
Hepatic circulation; ligamentum venosum
6-30
25. What embryologic structure provides the aorticpulmonary septum?
Neuroectoderm
Neural crest migration - they then cause spiral
Ring of pancreatic tissue can cause duodenal narrowing; ventral pancreatic bud abnormally encircles 2nd part of duodenum
blood entering the RA
26. In what chromosomal disorder is horseshoe kidney commonly seen? what poles of the kidneys fuse?
Turners; inferior
Surface ectoderm
Valproate acid
Partial closure of vitelline duct so that the patent portion is attached to ileum; ectopic gastric mucosa; melena and periumbilical pain
27. When does organogenesis occur?
IX; X
Polyhydramnios - Down syndrome - Esophageal/duodenal atresia - Imperforate anus - Meckel diverticulum
Neural crest cells
Week 3-8
28. What is the kidney that functions at the interim kidney in the 1st trimester? What does it later contribute to?
6th aortic arch
Failure to recanalize; 21
Yolk sac; 3rd week
Mesonephros; male genital system
29. From what aortic arch does the common carotid artery arise? what else arises from this arch?
Glans penis and corpus cavernosum and spongiosum; glans clitoris and vestibular bulbs
not covered
Post. sup wall; luteal phase
3rd; proximal part of the internal carotid artery
30. ______________ is associated with ventral curvature of the penis
Week 8
hypospadias
blood entering the RA
Mesoderm
31. From What embryonic layer do the parafollicular cells of the thyroid arise?
Neural crest cells
Surface ectoderm
No organ in each; agenesis no primordial tissue
SRY gene on Y chromosomes; sertoli and leydi; MIF and androgens; suppression of paramesonephric ducts and dev. of mesonephric (all respectively)
32. What does the RET gene encode? what neoplasias is it associated with?
Neural crest development; MEN 2A (pheo - PTH tumor - parafollicular cell tumor)
arnold chiari associated with thoraclumbar myelomeningocele
Mesencephalon
Neuroectoderm
33. What is omphalocele? In What trisomies is it seen?
Maternally derived; meconium
Surface ectoderm
Where the epiblast and hypoblast fuse
Persistance of herniation of abdominal contents into umbilical cord covered by peritoneum; 13 - 18
34. Where is the most common ectopic thyroid tissue?
Tongue
Aortic arch and prox part of subclavian
Indomethacin; blocks PG production
Neural crest cells
35. What is a zygote?
Nutrient and gas for exchange; endometrium
Neuroectoderm
Rostral fold closure ; lateral fold closure; lateral fold closure; caudal fold closure
Sperm plus egg
36. What embryologic structure gives rise to the smooth outflow tracts of the ventricles? what else does it give rise to?
Annular pancrease
Lots - cleft palate/lip
elevated AFP
Bulbos Cordis; right ventricle entirely
37. Pyloric stenosis is characterized by _____________ of muscularis externis in the sphincter
Neural crest cells
All 3
Valproate acid
hypertrophy
38. what closes the ductus arteriousus?
Mesoderm
Increase in oxygen concentration which decreases prostaglandin concentration
Ventral bud
Day 6; with implantation
39. From where does the prostate develop? seminal vesicles? fallopian tube? lower 2/3 of the vagina? ejaculatory duct? epididymis? uterus? upper 1/3 of the vagina?
Week 8
Dorsal; sensory
Urogenital sinus; wolffian duct; mullerian duct; urogenital sinus; wolffian duct; wolffian duct; mullerian; mullerian
Sonic Hedgehog
40. In both meningocele and myelomeningocele the dura...
Turners; inferior
Physiologic incomplete muscular ventricular septum
is no longer intact
Bones - cartilage - and nerves
41. What embryological structure gives rise to the smooth part of the right atrium?
Grooves/clefts; arches; pouches
septum primum and/or secundum
Right horn of the SV
Umbilical - midgut herniates through umbilical ring; SMA
42. Most myelomeningoceles present in the _______ region
Occiptal
Mesoderm
not covered
lumbosacral
43. What is another name for the mesonephric duct? paramesonephric?
Telencephalon
Wolffian; mullerian
From endocardial cushions (ventral and dorsal meet each other)
Mullerian inhibitory factor from Sertoli cells; increased androgen from Leydig cells
44. From What embryonic layer do chromaffin cells arise?
Neuroectoderm
Neural crest cells
Indomethacin; blocks PG production
Metanephric mesenchyme; differentiation and formation of glomerulus and renal tubules to distal convoluted tubule
45. From What embryonic layer do the salivary - sweat and mammary glands arise?
Endoderm
Deformation
Surface ectoderm
Greater horn of hyoid; CN IX (styloPharyngeus)
46. When does the neural tube form and From what does it form?
Greater horn of hyoid; CN IX (styloPharyngeus)
Endoderm
DiGeorge
Neural plate; closes by week 4
47. What germ layer correlates with the branchial pouches?
Mesoderm
Endoderm
Cleft lip/palate
First branchial pouch
48. From where did a branchial cleft cyst arise if it found?
Surface ectoderm
Found in lateral neck; from no obliteration of 2-4th clefts
Tetracyclines
Neuroectoderm
49. is epispadias or hypospadias associated with exstrophy of the bladder?
Membrane - all 3 from 1st appartus
Epispadias
Persistent connection between amniotic cavity and spinal canal; low folic acid
Medial palatine processes
50. From which germlayer does the thyroid develop?? From what structure exactly?
Ectoderm
Surface ectoderm
Endoderm - floor of primitive pharynx
External auditory meatus