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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 type of blood do umbilical arteries carry? From where to where?
Congenital and chromosomal abnormalities
Ectoderm; endoderm
Deoxygenated blood; fetal internal iliac arteries to placenta
Bones - cartilage - and nerves
2. What separates the ant 1/3 and post 2/3 of tongue?
Neuroectoderm
Day 6; maintains corpus luteum; 1st trimester
Foramen cecum and terminal sulus
Neural crest migration - they then cause spiral
3. From What embryonic layer do the ANS arise?
Nicotine; preterm labor
Valproate acid
Ectoderm
Neural crest cells
4. What does DHT turn the urogenital sinus into? estrogen?
6th aortic arch
Neuroectoderm
Muscular ventricular septum; no
Bulbourethral glands (of Cowper) and Prostate gland; greater vestibular glands (of Bartholin) and Urethral and paraurethral glands (of Skene)
5. From where to Where is the foregut derivative? midgut? hindgut?
Ectoderm; endoderm
2; 1
Rostral fold closure ; lateral fold closure; lateral fold closure; caudal fold closure
Pharynx to duodenum; duodenum to transverse colon; distal transverse colon to rectum
6. From where does the medulla form?
Aberrant development of 3rd and 4th pouches; t cell def (thymic aplasia) - hypocalcemia (failure of parathyroid development) - CF and CV defects
OCPS and maternal diabetes
Neuroectoderm
Myelencephalon
7. What day is the chorion formed?
Neural crest cells
Ampulla
Neuroectoderm
3
8. what else is the caudal regression known as? What two teratogen can cause this in the fetus?
Mesoderm
Foregut; dorsal mesentery (mesodermal)
VACTERL; OCPs and maternal diabetes
Before getting pregnant!
9. What do the arches of the branchial apparatus correlate to?
Mesdoerm
2nd pouch
Occiptal
Dorsal ventral axis
10. what structures are the derivatives of the neural crest cells in branchial arches?
Neural plate; closes by week 4
Ebsteins anomaly; tricuspid atresia
Telencephalon
Bone/cartilage and nerves
11. Where is the mothers blood located in the placenta?
Absent cerebellar vermis; cystic enlargement of 4th ventricle
Lacunae in between the chorionic villi
Endometrium
Initial left to right shunting - then switches
12. Which parts of the pancreas contribute to the head - uncinate process and main pancreatic duct?
Ectoderm; endoderm
Dorsal and ventral buds
Annular pancrease
Membrane - all 3 from 1st appartus
13. What embryologic structure provides the aorticpulmonary septum?
Week 8
Neural crest migration - they then cause spiral
Nutrient and gas for exchange; endometrium
All 3
14. What is the neural plate and From what does it form?
Ventral bud
Right common cardinal vein and right anterior cardinal vein
3rd; proximal part of the internal carotid artery
Ectoderm
15. What does DHT turn the genital tubercle into? estrogen?
Oxygenated; placenta to fetus (IVC)
Glans penis and corpus cavernosum and spongiosum; glans clitoris and vestibular bulbs
Ventral bud
Myelencephalon
16. From What embryonic layer does bone of the skulls arise?
Neural crest cells
Polyhydramnios - Down syndrome - Esophageal/duodenal atresia - Imperforate anus - Meckel diverticulum
Hemorrhage - bone deformities
Excessive resorption of septum primum or secondum (or both)
17. in hypospadias - on which side is the abnormal opening? What causes it?
Ventral; failure of urogenital folds to close
Grooves/clefts; arches; pouches
Bone/cartilage and nerves
Neuroectoderm
18. What secretes hCG?
Persistance of herniation of abdominal contents into umbilical cord covered by peritoneum; 13 - 18
Endometrium
Synctiotrophoblast
DES
19. What type of - amnios does bilateral agenesis form? What three symptoms does this cause?
Dorsal ventral axis
All or none
Oligohydramnios
Maxillary
20. From What embryonic layer is the vagina from? testes? ovaries?
Endoderm
DiGeorge
Physiologic incomplete muscular ventricular septum
Mesoderm
21. What effect does warfarin have on the fetus?
Hemorrhage - bone deformities
Mesencephalon
Alkylating agents
Failure to spiral (aorta coming out of RV and PA coming out of left ventricle)- two completely separate systems
22. At what week does the fetus look like a baby?
Cerebellar tonsillar herniation through foramen magnum
Pronephros - mesonephros - metanephros; pronephros; most cranially
Day 6; with implantation
Week 8
23. What artery is derived branchial (aortic) arch 3?
Right horn of the SV
IX; X
VACTERL- vertebral defect - anal atresia - cardiac defects - tracheo - esophageal fistula - renal defects - limb defects
Common carotid and internal carotid
24. Which branchial apparatus develops into the thymus?
Female; paramesonephric; mesonephric
3rd pouch
Fallopian tube - uterus - upper 1/3 of vagina
Ventral; failure of urogenital folds to close
25. what drug is used to help close a PDA? what else does this drug treat?
Obliterated
Primitive ventricle
Indomethacin; blocks PG production
Truncus arteriosus; pulmonary trunk
26. What is the effect of teratogens before week 3?
Week 3; primitive streak formation from the epiblast makes the three layers
Endoderm
All or none
SRY gene on Y chromosomes; sertoli and leydi; MIF and androgens; suppression of paramesonephric ducts and dev. of mesonephric (all respectively)
27. Which part of the branchial apparatus makes up membranes?
Oxygenated; placenta to fetus (IVC)
Urogenital sinus; wolffian duct; mullerian duct; urogenital sinus; wolffian duct; wolffian duct; mullerian; mullerian
All 3
Endoderm
28. ______________ is associated with ventral curvature of the penis
Aminoglycosides
Urachus/median umbilical ligament; bladder and yolk sac
hypospadias
8
29. What are the aspects of fetal alcohol syndrome?
Neural crest development; MEN 2A (pheo - PTH tumor - parafollicular cell tumor)
Cerebellar tonsillar herniation through foramen magnum
Mental retardation - holoprosencephaly - facial features - fistulas
Neural crest cells
30. What is DiGeorge syndrome and What does it result in?
DiGeorge
Aberrant development of 3rd and 4th pouches; t cell def (thymic aplasia) - hypocalcemia (failure of parathyroid development) - CF and CV defects
80%
Palpable olive mass in epigastric region; nonbilious projectile vomitting @around 2 weeks
31. From which branchial derivative does the anterior 2/3 of the tongue develop?
1st branchial arch
Respiratory distress syndrome
VACTERL- vertebral defect - anal atresia - cardiac defects - tracheo - esophageal fistula - renal defects - limb defects
Deformation
32. What is the female remnant of the gubernaculum? male remnant?
Mesoderm
Ovarian ligament and round ligament of uterus; anchors testes within scrotum
mesodermal
V3; VII
33. How does annular pancreas present in children?
Gastric outlet obstruction (bilious vomiting - feeding intolerance - abdominal distention)
Upper 1/3; urogenital sinus
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)
Week 4
34. During what periods do the damages that cerebral palsy causes occur?
Palpable olive mass in epigastric region; nonbilious projectile vomitting @around 2 weeks
3rd and 4th arches
Prenatal and perinatal
Arches 3 and 4
35. which posterior fossa malformation results in aqueductal stenosis and hydrocephaly? what other spinal cord lesion does this malformation present with?
Bones - cartilage - and nerves
Thickened ectoderm at end of each developing limb
ACE inhibitors - HCTZ
Arnold chiari; syringomyelia
36. From What embryonic layer does connective tissue and muscle arise?
Common carotid and internal carotid
External auditory meatus
Turners; inferior
Mesoderm
37. What is the primitive streak? From what layer does it form?
Valproate acid
Endoderm
Mesoderm; epiblast
Surface ectoderm
38. Which branchial derivative accounts for the posterior 2/3 of the tongue?
3rd and 4th arches
Partial AP septum development; one large vessel leaves the heart - Right to left shunt
Neural crest cells
Neural crest development; MEN 2A (pheo - PTH tumor - parafollicular cell tumor)
39. What is the leading cause of birth defects in the US? what else is this perpetrator the leading cause of?
Mesoderm; 3 week
Surface ectoderm
Thyroglossal duct cysts will move with swallowing while persistent cervical sinuses in lateral neck wont
Fetal alcohol syndrome; mental retardation
40. From What embryonic layer does a craniopharygioma arise?
Before getting pregnant!
LH
Surface ectoderm
Maternally derived; meconium
41. What causes the degeneration of the spinal cord in syringomelia?
Tetracyclines
Mesoderm; 3 week
Fluid filled syrinx causes expansion and degeneration of cord tracts
Blastocyst; epiblast and hypoblast; synctiotrophoblast and cytotrophoblast
42. What teratogen can cause an absence of digits amongst other things in the fetus? give an example.
Aortic arch and prox part of subclavian
Alkylating agents
Cytotrophoblast
Fetal alcohol syndrome; mental retardation
43. What weeks are considered the 'embryonic period'?
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
Ventral bud
Week 3-8
Meckels cartilage: mandible - malleus - INCUS - sphenoMandibular ligament; CN V2 and V3
44. From where is amniotic fluid produced? other than electrolytes and carbs - what else does it contain?
StyloPharyngeus
Metanephric mesenchyme; differentiation and formation of glomerulus and renal tubules to distal convoluted tubule
Maternally derived; meconium
Meckels cartilage: mandible - malleus - INCUS - sphenoMandibular ligament; CN V2 and V3
45. what muscles are derived from branchial arch 3?
Lithium; valve leaflets attach to domain down low in RV- 'atrialized RV'
pyloric stenosis
Failure of the urachus to obliterate; outpouching of the bladder
StyloPharyngeus
46. What are the three results of having pathology in the aorticopulmonary septum?
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)
Duodenum to transverse colon; distal transverse colon to rectum
mesodermal
Mesoderm
47. From What embryonic layer does the epithelial linings of the oral cavity arise?
Surface ectoderm
1st arch neural crest fails to migrate --> mandibular hypoplasia - facial abnormalities (cleft palate - decreased slanting of palpebral fissures)
When left to right shunting switching to right to left shunting
Initial left to right shunting - then switches
48. From what region of the brain does the lateral ventricles and the 3rd ventricle form?
Fluid filled cavity in spinal cord; C8- T1; arnold chiari II
Surface ectoderm
Prosencephalon
Urachus/median umbilical ligament; bladder and yolk sac
49. What is Treacher Collins syndrome? What is the result?
Polyhydramnios - Down syndrome - Esophageal/duodenal atresia - Imperforate anus - Meckel diverticulum
1st arch neural crest fails to migrate --> mandibular hypoplasia - facial abnormalities (cleft palate - decreased slanting of palpebral fissures)
During; instrinsic
Upper 1/3; urogenital sinus
50. When does organogenesis occur?
3rd pouch
Surface ectoderm
Decreased separation of hemispheres across midline; cyclopia
Week 3-8