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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 is more common - epispadias or hypospadias?
Neuroectoderm
Hypospadias
3 -4 -6
From teh lung;blood from IVC in RA to LA; fossa ovalis
2. What is the leading cause of birth defects in the US? what else is this perpetrator the leading cause of?
Grooves/clefts; arches; pouches
T neuroectoderm
Mid gut to yolk sac; omphalomesenteric duct; 7th week
Fetal alcohol syndrome; mental retardation
3. What causes tetralogy of Fallot?
Congenital and chromosomal abnormalities
Skewed development of AP septum
DiGeorge
A vitelline fistula - failure of vitelline duct to close
4. What secretes hCG?
Cranio - caudal; segmental
Incomplete; yes
Synctiotrophoblast
...
5. What embryological structure gives rise to the coronary sinus?
Tongue
Prenatal and perinatal
Week 10-12; end of 1st trimester
Left horn of the sinus venosus
6. From What embryonic layer is the vagina from? testes? ovaries?
Dorsal and ventral buds
Lacunae in between the chorionic villi
Incomplete fusion of paramesonephric ducts; UT abnormalities and infertility
Mesoderm
7. From What embryonic layer are the cardiovascular - lymphatics and blood from?
Pharynx to duodenum; duodenum to transverse colon; distal transverse colon to rectum
Nutrient and gas for exchange; endometrium
Mesoderm
Reicherts cartilage: Stapes - Styloid process - Lesser horn of hyloid - Stylohyoid ligament and CN VII
8. When does the neural tube form and From what does it form?
Congenital and chromosomal abnormalities
XII
Neural plate; closes by week 4
Decidual basalis
9. Blood coming in the umbilical vein is ____ saturated
Mesoderm
Mesoderm
80%
ACE inhibitors - HCTZ
10. What are the three results of having pathology in the aorticopulmonary septum?
Foregut; dorsal mesentery (mesodermal)
Greater horn of hyoid; CN IX (styloPharyngeus)
Scrotum; labia majora
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)
11. What teratogens can cause CN VIII toxicity in the fetus?
Neural crest cells
Decidual basalis
Neuroectoderm
Aminoglycosides
12. From What embryonic layer does bone arise ?
Neural crest cells
VACTERL- vertebral defect - anal atresia - cardiac defects - tracheo - esophageal fistula - renal defects - limb defects
Endometrium
Mesoderm
13. What is the 'fetal period'- ie When is it?
Week 3-8
Failure of bony spinal canal to fuse; no; lower vertebral levels
Prostaglandins
Week 8
14. 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
Spinothalamic first
Muscles of facial expression - stapedius - stylohyoid - posterior belly of the digastric
Failure of the urachus to obliterate
15. Where is the mothers blood located in the placenta?
Lacunae in between the chorionic villi
Rostral fold closure ; lateral fold closure; lateral fold closure; caudal fold closure
Surface ectoderm
Umbilical - midgut herniates through umbilical ring; SMA
16. What are the two walls of the prosencephalon and What do they become?
Cerebral hemisphere - thalami
Muscles of facial expression - stapedius - stylohyoid - posterior belly of the digastric
Rhombencephalon
Bilateral loss of pain and temperature sensation in upper extremities with preservation of touch sensation
17. What is congenital pharyngocutaneous fistula? and How does it occur?
elevated AFP
Persistence of 3rd cleft (groove) and pouch causes fistula between tonsillar area and cleft in lateral neck
Mesencephalon
...
18. what separates the atria from the ventricles?
Endocardial cushions
Partial AP septum development; one large vessel leaves the heart - Right to left shunt
4th arch; 6th arch
Neural crest migration - they then cause spiral
19. What teratogens can cause renal damage in the fetus?
Mesoderm; 3 week
ACE inhibitors - HCTZ
Neuroectoderm
Mid gut to yolk sac; omphalomesenteric duct; 7th week
20. Which branchial derivative accounts for the posterior 2/3 of the tongue?
Mesencephalon
3rd and 4th arches
Thyroglossal duct; persists as pyramidal lobe of thyroid; foramen cecum on tongue is normal remnant of thyroglossal duct
Oligohydramnios
21. What teratogens can cause discolored teeth?
Pulm art (prox) and ductus arteriosus
Endoderm lined structures of ear: middle ear cavity - eustacian tube - mastoid air cells
Tetracyclines
3rd and 4th arches
22. what other facial defect other than cyclopia is associated with holoprosencephaly?
Cleft lip/palate
Synctiotrophoblast
All or none
Occiptal
23. What are two common findings in pyloric stenosis?
Palpable olive mass in epigastric region; nonbilious projectile vomitting @around 2 weeks
Failure of the urachus to obliterate; outpouching of the bladder
hypospadias
Neuroectoderm
24. what bone/cartilage and nerves are derived from branchial arch 3?
Ectoderm; endoderm
Pronephros - mesonephros - metanephros; pronephros; most cranially
Greater horn of hyoid; CN IX (styloPharyngeus)
Mesoderm
25. Name a syndrome cleft palate is often seen in
Caused by compression on trocheal nerve - causes vertical gaze paralysis (associated with arnold chiari)
DiGeorge
Turners; inferior
StyloPharyngeus
26. From what does bicornuate uterus arise? What is it associated with?
They are the edge of neural plate folding; all over the body
Incomplete fusion of paramesonephric ducts; UT abnormalities and infertility
Neuroectoderm
Fetal kidney; fetal swallows - absorbs - and then removed from placental blood
27. From What embryonic layer does the neurohypophysis arise?
Neuroectoderm
...
Ventral ; motor
4th arch; 6th arch
28. From where to Where is the foregut derivative? midgut? hindgut?
Persistance of herniation of abdominal contents into umbilical cord covered by peritoneum; 13 - 18
Prosencephalon - mesencephalon - rhombencephalon
Pharynx to duodenum; duodenum to transverse colon; distal transverse colon to rectum
Week 10-12; end of 1st trimester
29. During what months is the fetus most susceptible to teratogens? What trimester?
Right common cardinal vein and right anterior cardinal vein
Embryonic period; 1st trimester
Hypertrophy of muscularis externis of pylorus; surgical incision
Ventral bud
30. In both meningocele and myelomeningocele the dura...
Metencephalon; cerebellum
3rd and 4th arches
Decreased pulmonary resistance in the pulmonary vasculature
is no longer intact
31. What artery is derived branchial (aortic) arch 2?
Stapedius and hyoid artery
Failure of the urachus to obliterate
Left horn of the sinus venosus
mesoderm
32. What is the most common autopsy finding in brains of premature infants?
2; 1
Germinal matrix hemorrhage
Dorsal; sensory
Neuroectoderm
33. What is the memranous interventricular formaen made from?
Decreases
Hypospadias
6-30
When the AP septum meets and fuses with the muscular ventricular septum to form membranous intraventricular septum - closing interventricular foramen
34. What is the initial step to interventricular septum development? is it complete?
Muscles of facial expression - stapedius - stylohyoid - posterior belly of the digastric
Prenatal and perinatal
Hemorrhage - bone deformities
Muscular ventricular septum; no
35. What is the effect of teratogens before week 3?
When the AP septum meets and fuses with the muscular ventricular septum to form membranous intraventricular septum - closing interventricular foramen
Failure of the urachus to obliterate
All or none
Fluid filled syrinx causes expansion and degeneration of cord tracts
36. which posterior fossa malformation results in aqueductal stenosis and hydrocephaly? what other spinal cord lesion does this malformation present with?
Branchial arch 2
1st
Arnold chiari; syringomyelia
1st branchial arch
37. What congenital abnormality forms a 'double bubble' on xray?
Spinothalamic first
20-50yrs - Abdominal pain - Postprandial fullness - Nausea - Peptic ulcers - Pancreatitis - Rarely - biliary obstruction
Annular pancrease
Failure of bony spinal canal to fuse; no; lower vertebral levels
38. From which myotomes are muscles of the tongue derived from?
Persistance of herniation of abdominal contents into umbilical cord covered by peritoneum; 13 - 18
Failure of the urachus to obliterate; outpouching of the bladder
Mesoderm
Occiptal
39. What type of radiation is teratogenic ?
primary palate
Ionizing
StyloPharyngeus
Neural crest cells
40. What arises from the fourth aortic arch?
Aortic arch (from left side); right subclavian (on the right)
Endoderm
Telencephalon
Neuroectoderm
41. what chemo drugs can cause neural tube defects in the fetus?
3rd pouch
Folate antagonists
Ectoderm
Endometrium
42. What day is the amnion formed?
8
Mid gut to yolk sac; omphalomesenteric duct; 7th week
28 week onward
Failure of bony spinal canal to fuse; no; lower vertebral levels
43. From What embryonic layer does the olfactory epithelium arise?
septum primum and/or secundum
Yolk sac; 3rd week
Maxillary
Surface ectoderm
44. From what region of the brain does the aqueduct form?
Rhombencephalon
Primitive atrium
DiGeorge
Ebsteins anomaly; tricuspid atresia
45. What does the RET gene encode? what neoplasias is it associated with?
Neural crest development; MEN 2A (pheo - PTH tumor - parafollicular cell tumor)
Neural crest cells
Right common cardinal vein and right anterior cardinal vein
Myelencephalon
46. From what germ layer does the primitive heart tube arise?
Medial palatine processes
Mesoderm
Neural crest development; MEN 2A (pheo - PTH tumor - parafollicular cell tumor)
monoamniotic
47. From What embryonic layer do the ependymal cells arise?
Neural crest cells
Neuroectoderm
Ectoderm
Bilateral loss of pain and temperature sensation in upper extremities with preservation of touch sensation
48. what invaginates to form the primitive streak?
Dorsal; faulty positioning of genital tubercle
Cerebellar tonsillar herniation through foramen magnum
Epiblast
Amniotic cavity and yolk sac
49. Which branchial apparatus develops into the inferior parathyroids?
Umbilical - midgut herniates through umbilical ring; SMA
Greater horn of hyoid; CN IX (styloPharyngeus)
3rd pouch
Tongue
50. What trisomy is associated with holoprosencephaly? What teratogen?
External auditory meatus
Neural crest cells
Apical ectodermal ridge
Pataus; fetal alcohol syndrome