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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. When does organogenesis occur?
Ectoderm
Cranio - caudal; segmental
Fluid filled syrinx causes expansion and degeneration of cord tracts
Week 3-8
2. What does the foramen ovale shunt blood from - to where? What is its remnant?
From teh lung;blood from IVC in RA to LA; fossa ovalis
Outgrowth of mesonephric as ureteric bud; most caudal
Fetal kidney; fetal swallows - absorbs - and then removed from placental blood
Deformation
3. What does the mullerian duct develop into? wollffian?
Neural crest cells
Fallopian tube - uterus - upper 1/3 of vagina
Yolk sac; liver (weeks 6-30) and spleen (9-28 weeks)
Initial left to right shunting - then switches
4. What type of radiation is teratogenic ?
Telencephalon
Polyhydramnios - Down syndrome - Esophageal/duodenal atresia - Imperforate anus - Meckel diverticulum
Ionizing
Week 8
5. How does annular pancreas present in children?
Gastric outlet obstruction (bilious vomiting - feeding intolerance - abdominal distention)
V3; VII
Day 6; maintains corpus luteum; 1st trimester
Right common cardinal vein and right anterior cardinal vein
6. What type of - amnios does bilateral agenesis form? What three symptoms does this cause?
Cerebellar tonsillar herniation through foramen magnum
Mesoderm
Oligohydramnios
Rhombencephalon
7. Which CN allows for taste and sensation in the posterior 1/3 of the tongue? how about the very back ?
Metencephalon; cerebellum
Maxillary
IX; X
OCPS and maternal diabetes
8. Where is the mothers blood located in the placenta?
Failure to recanalize; 21
Ectoderm
Aminoglycosides
Lacunae in between the chorionic villi
9. What connects the thyroid to the tongue? when happens if it doesnt obliterate?
Mesencephalon
Thyroglossal duct; persists as pyramidal lobe of thyroid; foramen cecum on tongue is normal remnant of thyroglossal duct
Endometrium
Bulbourethral glands (of Cowper) and Prostate gland; greater vestibular glands (of Bartholin) and Urethral and paraurethral glands (of Skene)
10. What day is the chorion formed?
Arches 3 and 4
Telencephalon
Mesoderm
3
11. What embryological structures give rise to the SVC?
elevated AFP
Failure of bony spinal canal to fuse; no; lower vertebral levels
Right common cardinal vein and right anterior cardinal vein
hypospadias
12. What components do the mesoderm of the branchial arches give rise to?
Mullerian inhibitory factor from Sertoli cells; increased androgen from Leydig cells
Muscles and arteries
Mesoderm
Endocardial cushions
13. What causes persistent Truncus Arteriosus? What does it result in?
Before getting pregnant!
Tongue
Partial AP septum development; one large vessel leaves the heart - Right to left shunt
...
14. What teratogen can cause vaginal clear cell adenocarcinoma in the fetus?
Tongue
Lots - cleft palate/lip
DES
Umbilical artery - vein; and whartons jelly (mucus connective tissue) - urachus
15. What trisomy is associated with holoprosencephaly? What teratogen?
Neuroectoderm
4th arch; 6th arch
Urogenital sinus; wolffian duct; mullerian duct; urogenital sinus; wolffian duct; wolffian duct; mullerian; mullerian
Pataus; fetal alcohol syndrome
16. From what aortic arch does the common carotid artery arise? what else arises from this arch?
3rd; proximal part of the internal carotid artery
Polyhydramnios - Down syndrome - Esophageal/duodenal atresia - Imperforate anus - Meckel diverticulum
3rd pouch
Week 4; week 3
17. As a horseshoe kidney ascends during kidney development - What do they get trapped under?
Ionizing
IMA
Tetracyclines
Prostaglandins
18. What is the notochord? What does the notochord later become?
Mesoderm; nucleous pulposos
Thyroglossal duct cysts will move with swallowing while persistent cervical sinuses in lateral neck wont
Prosencephalon
Lithium; valve leaflets attach to domain down low in RV- 'atrialized RV'
19. what chemo drugs can cause neural tube defects in the fetus?
Valproate acid
Gastric outlet obstruction (bilious vomiting - feeding intolerance - abdominal distention)
is no longer intact
Folate antagonists
20. From where do the three different kidneys come from? Which is the earliest one? is it located most cranially or caudally?
Endoderm
Pronephros - mesonephros - metanephros; pronephros; most cranially
Hypospadias
Persistence of 3rd cleft (groove) and pouch causes fistula between tonsillar area and cleft in lateral neck
21. Which branchial apparatus makes the external auditory meatus?
Lithium; valve leaflets attach to domain down low in RV- 'atrialized RV'
SRY gene on Y chromosomes; sertoli and leydi; MIF and androgens; suppression of paramesonephric ducts and dev. of mesonephric (all respectively)
5th
1st cleft/groove (Ectoderm)
22. What arises from the fourth aortic arch?
Endometrium
Increase in oxygen concentration which decreases prostaglandin concentration
Aortic arch (from left side); right subclavian (on the right)
Neuroectoderm
23. what closes the ductus arteriousus?
A vitelline fistula - failure of vitelline duct to close
Dorsal; faulty positioning of genital tubercle
Increase in oxygen concentration which decreases prostaglandin concentration
Thyroglossal duct cysts will move with swallowing while persistent cervical sinuses in lateral neck wont
24. What is the Eisenmeger complex?
When left to right shunting switching to right to left shunting
First branchial pouch
ACE inhibitors - HCTZ
Thyroid - cricoid - arytenoids - corniculate cuneiform
25. During what week does the heart begin to beat?
Surface ectoderm
Week 4
Maxillary and medial nasal processes
Hypospadias
26. which tracts are damaged first in syringomelia? What tract is preserved?
Spinothalamic first
4th arch; 6th arch
Arnold chiari; syringomyelia
Neuroectoderm
27. What are the clinical symptoms that present with syringomelia?
Increased AFP and acetycholinesterase (not ACh!) in CSF
Hypertrophy of muscularis externis of pylorus; surgical incision
Bilateral loss of pain and temperature sensation in upper extremities with preservation of touch sensation
can make cells
28. What is DiGeorge syndrome and What does it result in?
Neural crest cells
No more umbilical circulation emptying into RA
Week 10-12; end of 1st trimester
Aberrant development of 3rd and 4th pouches; t cell def (thymic aplasia) - hypocalcemia (failure of parathyroid development) - CF and CV defects
29. 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
Persistent connection between amniotic cavity and spinal canal; low folic acid
Oligohydramnios
External auditory meatus
30. What causes meconium discharge from the umbilicus?
They are the edge of neural plate folding; all over the body
A vitelline fistula - failure of vitelline duct to close
Metanephric mesenchyme; differentiation and formation of glomerulus and renal tubules to distal convoluted tubule
Amniotic epithelium
31. From where does pons form from? what else forms from there?
Metencephalon; cerebellum
Dorsal ventral axis
Right common cardinal vein and right anterior cardinal vein
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)
32. In order to survive tricuspid atresia - What do you need?
VSD
Upper 1/3; urogenital sinus
Prosencephalon - mesencephalon - rhombencephalon
Cerebral hemisphere - thalami
33. what other facial defect other than cyclopia is associated with holoprosencephaly?
Meckels cartilage: mandible - malleus - INCUS - sphenoMandibular ligament; CN V2 and V3
Thyroglossal duct; persists as pyramidal lobe of thyroid; foramen cecum on tongue is normal remnant of thyroglossal duct
Cleft lip/palate
Temporary cervical sinus
34. What is hypoplasia? is primordial tissue present?
Incomplete; yes
Apical ectodermal ridge
Endoderm
4th/5th branchial pouches
35. Cleft lip is a failure of formation of the...
Week 2; bilaminar disk; epiblast and hypoblast
A vitelline fistula - failure of vitelline duct to close
primary palate
Duodenum to transverse colon; distal transverse colon to rectum
36. What is the kidney that functions at the interim kidney in the 1st trimester? What does it later contribute to?
2nd; 2nd
Polyhydramnios - Down syndrome - Esophageal/duodenal atresia - Imperforate anus - Meckel diverticulum
Mesonephros; male genital system
Endoderm
37. From What embryonic layer is the bladder and urethra from?
Incomplete; yes
Thyroglossal duct; persists as pyramidal lobe of thyroid; foramen cecum on tongue is normal remnant of thyroglossal duct
Fluid filled syrinx causes expansion and degeneration of cord tracts
Mesoderm
38. What is the initial step to interventricular septum development? is it complete?
Lacunae in between the chorionic villi
1st cleft/groove (Ectoderm)
Muscular ventricular septum; no
Neuroectoderm
39. From What embryonic layer does the oligodendrocytes arise?
Neuroectoderm
Tunica vaginalis not fully fused
Renal artery stenosis;
...
40. From What embryonic lare are the odontoblasts from?
Neural crest cells
monoamniotic
Foregut; dorsal mesentery (mesodermal)
Decreased pulmonary resistance in the pulmonary vasculature
41. What can vit A in excess cause in the fetus?
Prevent recurrent UTIs
Lots - cleft palate/lip
Arches 3 and 4
Annular pancrease
42. From what region of the brain does the aqueduct form?
Most pharyngeal constrictors - Cricothyroid - levator veli palatini; CN X (superior laryngeal branch - swallowing)
Rhombencephalon
Yolk sac; 3rd week
2nd pouch
43. what bone/cartilage and nerves are derived from branchial arch 2?
3rd pouch
Reicherts cartilage: Stapes - Styloid process - Lesser horn of hyloid - Stylohyoid ligament and CN VII
Cerebral hemisphere - thalami
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
44. What is a syrinx? Where is it found in syringomelia? What is it associated with?
Fluid filled cavity in spinal cord; C8- T1; arnold chiari II
Neural crest cells
Mid gut to yolk sac; omphalomesenteric duct; 7th week
Found in lateral neck; from no obliteration of 2-4th clefts
45. What are the three results of having pathology in the aorticopulmonary septum?
Fetal kidney; fetal swallows - absorbs - and then removed from placental blood
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)
Branchial arch 2
Rostral fold closure ; lateral fold closure; lateral fold closure; caudal fold closure
46. in hypospadias - on which side is the abnormal opening? What causes it?
Ventral; failure of urogenital folds to close
Neural crest cells
Lots - cleft palate/lip
Aminoglycosides
47. which teratogen can cause Ebsteins anomaly in the fetus?
Mid gut to yolk sac; omphalomesenteric duct; 7th week
Decreased pulmonary resistance in the pulmonary vasculature
Ampulla
Lithium
48. From What embryonic layer does the skin dermis arise?
Mesoderm
Week 10-12; end of 1st trimester
...
Endocardial cushions
49. what bone/cartilage and nerves are derived from branchial arch 3?
elevated AFP
Greater horn of hyoid; CN IX (styloPharyngeus)
Sperm plus egg
Prevent recurrent UTIs
50. Name two endocardial cushion defects.
Ebsteins anomaly; tricuspid atresia
Found in lateral neck; from no obliteration of 2-4th clefts
Meckels cartilage: mandible - malleus - INCUS - sphenoMandibular ligament; CN V2 and V3
Ectoderm; endoderm