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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 artery is derived branchial (aortic) arch 6?
Surface ectoderm
Turners; inferior
blood entering the RA
Pulm art (prox) and ductus arteriosus
2. ______________ is associated with ventral curvature of the penis
Ventral bud
hypospadias
Surface ectoderm
Week 3-8
3. What does the maternal component of the placenta provide? Where is it derived from?
Meckels cartilage: mandible - malleus - INCUS - sphenoMandibular ligament; CN V2 and V3
Neuroectoderm
Upper 1/3; urogenital sinus
Nutrient and gas for exchange; endometrium
4. Which branchial apparatus develops into the thymus?
Mesoderm
Ventral shaft of penis (penile urethra); labia minora
3rd pouch
From endocardial cushions (ventral and dorsal meet each other)
5. When is most important to take folic acid to prevent neural tube defects?
Synctiotrophoblast; outer; no
Partial AP septum development; one large vessel leaves the heart - Right to left shunt
Before getting pregnant!
not covered
6. What embryological structure gives rise to the trabeculated part of the left and right atrium?
Cytotrophoblast and synctiotrophoblast
Primitive atrium
Tetracyclines
Apical ectodermal ridge; limb lengthening; stimulates mitosis of underlying mesoderm
7. What is the Eisenmeger complex?
Synctiotrophoblast
When left to right shunting switching to right to left shunting
Pataus; fetal alcohol syndrome
Urogenital sinus; wolffian duct; mullerian duct; urogenital sinus; wolffian duct; wolffian duct; mullerian; mullerian
8. From where is the allantois formed? During what week?
Yolk sac; 3rd week
Mesoderm
2nd pouch
Lots - cleft palate/lip
9. What embryological structures give rise to the SVC?
Ectoderm; endoderm
Right common cardinal vein and right anterior cardinal vein
Nutrient and gas exchange
When the AP septum meets and fuses with the muscular ventricular septum to form membranous intraventricular septum - closing interventricular foramen
10. When does the neural tube form and From what does it form?
Neural plate; closes by week 4
Dorsal ventral axis
Polyhydramnios - Down syndrome - Esophageal/duodenal atresia - Imperforate anus - Meckel diverticulum
Reicherts cartilage: Stapes - Styloid process - Lesser horn of hyloid - Stylohyoid ligament and CN VII
11. At what week does the fetus look like a baby?
Week 8
Surface ectoderm
Surface ectoderm
Neuroectoderm
12. which teratogen can cause Ebsteins anomaly in the fetus?
Thyroglossal duct cysts will move with swallowing while persistent cervical sinuses in lateral neck wont
Lithium
Decreased separation of hemispheres across midline; cyclopia
After; extrinsic
13. What happens in pancreas divisum? what results?
Ventral and dorsal parts fail to fuse at 8th week; 2 pancreatic ducts!- more prone to pancreatitis
Rhombencephalon
Medial palatine processes
Dorsal and ventral buds
14. What produces testis determining factor? what cells are produced from this? and What do they secrete? does this result in?
Arnold chiari; syringomyelia
Week 8
Tunica vaginalis not fully fused
SRY gene on Y chromosomes; sertoli and leydi; MIF and androgens; suppression of paramesonephric ducts and dev. of mesonephric (all respectively)
15. From which germlayer does the thyroid develop?? From what structure exactly?
Pataus; fetal alcohol syndrome
Turners; inferior
Deformation
Endoderm - floor of primitive pharynx
16. What is the most common subtype of tracheoesophageal fistula? name some symptoms (hint: O2 levels - feeding - stomach on CXR - - amnios? - NG tube? - respiratory infection? )
Deformation
...
Decreases
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
17. What teratogens can cause renal damage in the fetus?
ACE inhibitors - HCTZ
Aberrant development of 3rd and 4th pouches; t cell def (thymic aplasia) - hypocalcemia (failure of parathyroid development) - CF and CV defects
Nicotine; preterm labor
Neuroectoderm
18. From what region do the thalami form?
2nd pouch
Failure to spiral (aorta coming out of RV and PA coming out of left ventricle)- two completely separate systems
Diencephalon
Valproate acid
19. From What embryonic layer is the bladder and urethra from?
Post. sup wall; luteal phase
Apical ectodermal ridge; limb lengthening; stimulates mitosis of underlying mesoderm
Metanephric mesenchyme; differentiation and formation of glomerulus and renal tubules to distal convoluted tubule
Mesoderm
20. From What embryonic layer does the lens of the eye arise?
Bulbourethral glands (of Cowper) and Prostate gland; greater vestibular glands (of Bartholin) and Urethral and paraurethral glands (of Skene)
elevated AFP
Surface ectoderm
Muscles of facial expression - stapedius - stylohyoid - posterior belly of the digastric
21. Only _______________________________ are associated with neural tube defects
arnold chiari associated with thoraclumbar myelomeningocele
mesoderm
monoamniotic
Mesoderm
22. With the first breath the infant take - pulmonary vasculature resistance _______ which causes an increase in left atrial pressure
mesoderm
Ventral and dorsal parts fail to fuse at 8th week; 2 pancreatic ducts!- more prone to pancreatitis
Ventral ; motor
Decreases
23. What are the neural crest cells and where do they come form? where do they go?
They are the edge of neural plate folding; all over the body
3rd pouch
No more umbilical circulation emptying into RA
Neuroectoderm
24. When does hCG secretion take place? with what event?
Fetal kidney; fetal swallows - absorbs - and then removed from placental blood
Ectoderm; endoderm
Day 6; with implantation
Ventral and dorsal parts fail to fuse at 8th week; 2 pancreatic ducts!- more prone to pancreatitis
25. From where does the medulla form?
Decreased separation of hemispheres across midline; cyclopia
Scrotum; labia majora
Myelencephalon
Pulm art (prox) and ductus arteriosus
26. To what germ layer does the branchial pouches correlate to?
Endoderm
Yolk sac; liver (weeks 6-30) and spleen (9-28 weeks)
lumbosacral
Ventral ; motor
27. What results in annular pancreas? How does it happen?
Truncus arteriosus; pulmonary trunk
Ring of pancreatic tissue can cause duodenal narrowing; ventral pancreatic bud abnormally encircles 2nd part of duodenum
All intrinsic muscles of larynx except cricothyroid; CN X (recurrent laryngeal nerve - speaking)
...
28. From which branchial derivative does the anterior 2/3 of the tongue develop?
1st branchial arch
Rhombencephalon
Failure of the urachus to obliterate; outpouching of the bladder
Polyhydramnios
29. is epispadias or hypospadias associated with exstrophy of the bladder?
Neural crest cells
Epispadias
Prosencephalon - mesencephalon - rhombencephalon
Hemorrhage - bone deformities
30. What do the arches of the branchial apparatus correlate to?
Neural crest cells
Mesdoerm
primary palate
Failure of the urachus to obliterate; outpouching of the bladder
31. Which is more common - epispadias or hypospadias?
Blastocyst; epiblast and hypoblast; synctiotrophoblast and cytotrophoblast
Hypospadias
Cranio - caudal; segmental
Neuroectoderm
32. What does the midgut form? hindgut?
Greater horn of hyoid; CN IX (styloPharyngeus)
Duodenum to transverse colon; distal transverse colon to rectum
Dorsal and ventral buds
Branchial arch 2
33. What embryologic structure provides the aorticpulmonary septum?
Neural crest migration - they then cause spiral
Umbilical - midgut herniates through umbilical ring; SMA
Week 8
Neural crest cells
34. From what are the umbilical arteries and veins derived from?
Allantois
Mesoderm
Neuroectoderm
OCPS and maternal diabetes
35. What weeks are considered the 'embryonic period'?
Right common cardinal vein and right anterior cardinal vein
Surface ectoderm
Cranio - caudal; segmental
Week 3-8
36. What separates the ant 1/3 and post 2/3 of tongue?
Week 4
Foramen cecum and terminal sulus
Cranio - caudal; segmental
Excessive resorption of septum primum or secondum (or both)
37. From What embryonic layer does bone arise ?
No more umbilical circulation emptying into RA
elevated AFP
Mesoderm
DiGeorge
38. Which cranial nerve innervates the motor function of the tongue?
XII
Gastric outlet obstruction (bilious vomiting - feeding intolerance - abdominal distention)
After; extrinsic
Pronephros - mesonephros - metanephros; pronephros; most cranially
39. what else is the caudal regression known as? What two teratogen can cause this in the fetus?
Greater horn of hyoid; CN IX (styloPharyngeus)
VACTERL; OCPs and maternal diabetes
Rhombencephalon
Dorsal; sensory
40. What are the three results of having pathology in the aorticopulmonary septum?
Medial palatine processes
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)
Surface ectoderm
Annular pancrease
41. What is the homeobox gene responsible in developing? (What axis)
Week 8
Week 4
Cranio - caudal; segmental
Epispadias
42. What germ layer correlates with the branchial pouches?
1st
Ebsteins anomaly; tricuspid atresia
not covered
Endoderm
43. From what region of the brain does the lateral ventricles and the 3rd ventricle form?
80%
Dorsal ventral axis
Prosencephalon
Endometrium
44. How many umbilical arteries are there? How many umbilical veins?
VACTERL; OCPs and maternal diabetes
V3; VII
2; 1
Surface ectoderm
45. Where is the apical ectodermal ridge?
Thickened ectoderm at end of each developing limb
80%
Endoderm lined structures of ear: middle ear cavity - eustacian tube - mastoid air cells
Gastric outlet obstruction (bilious vomiting - feeding intolerance - abdominal distention)
46. Monochorionic - ___________ twins are conjoined
Allantois
Ectoderm; endoderm
monoamniotic
Ventral; failure of urogenital folds to close
47. From What embryonic layer does the oligodendrocytes arise?
Neuroectoderm
Fetal and maternal
Cerebral hemisphere - thalami
not covered
48. From What embryonic layer are the serous linings of the body cavities from? for ex - peritoneum?
...
lumbosacral
Amniotic cavity and yolk sac
Glans penis and corpus cavernosum and spongiosum; glans clitoris and vestibular bulbs
49. From What embryonic layer is aorticopulmonary septum from ?
Week 4; week 3
Primitive ventricle
Neural crest cells
Cranio - caudal; segmental
50. What does the mullerian duct develop into? wollffian?
Fallopian tube - uterus - upper 1/3 of vagina
Ectoderm
Bilateral loss of pain and temperature sensation in upper extremities with preservation of touch sensation
Ampulla