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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. Where is the FGF gene produced? What is it responsible for - How does it do this?
Glans penis and corpus cavernosum and spongiosum; glans clitoris and vestibular bulbs
External auditory meatus
Ventral shaft of penis (penile urethra); labia minora
Apical ectodermal ridge; limb lengthening; stimulates mitosis of underlying mesoderm
2. From What embryonic layer does the neurohypophysis arise?
IX; X
Myelencephalon
Neuroectoderm
Obliterated; forms tunica vaginalis
3. What causes the increase in left atrial pressure to close the fossa ovale?
Obliterated; forms tunica vaginalis
Decreased pulmonary resistance in the pulmonary vasculature
Thyroglossal duct cysts will move with swallowing while persistent cervical sinuses in lateral neck wont
Surface ectoderm
4. What is duodenal atresia usually due to? What trisomy is it most often seen in?
Tongue
Failure to recanalize; 21
First branchial pouch
Obliterated
5. what other facial defect other than cyclopia is associated with holoprosencephaly?
Urogenital sinus; wolffian duct; mullerian duct; urogenital sinus; wolffian duct; wolffian duct; mullerian; mullerian
Pulm art (prox) and ductus arteriosus
Cleft lip/palate
Increase in oxygen concentration which decreases prostaglandin concentration
6. In anencephaly you see...
Mesoderm
elevated AFP
Fallopian tube - uterus - upper 1/3 of vagina
Ventral; failure of urogenital folds to close
7. is epispadias or hypospadias associated with exstrophy of the bladder?
Female; paramesonephric; mesonephric
Mesoderm; nucleous pulposos
Neuroectoderm
Epispadias
8. At what week does the fetus look like a baby?
Week 8
primary palate
Neuroectoderm
Alkylating agents
9. What does the ductus venosus shunt blood away from? What is its remnant?
Hepatic circulation; ligamentum venosum
Rhombencephalon
Muscles and arteries
Incomplete; yes
10. What hormones are in charge of external genitalia development in the fetus? (in both male and female)
Germinal matrix hemorrhage
Physiologic incomplete muscular ventricular septum
IMA
DHT; estrogen
11. Where is the decidua basalis derived from?
Aminoglycosides
Endometrium
Indomethacin; blocks PG production
20-50yrs - Abdominal pain - Postprandial fullness - Nausea - Peptic ulcers - Pancreatitis - Rarely - biliary obstruction
12. What teratogens can cause renal damage in the fetus?
Spinothalamic first
ACE inhibitors - HCTZ
Neural crest development; MEN 2A (pheo - PTH tumor - parafollicular cell tumor)
Fetal kidney; fetal swallows - absorbs - and then removed from placental blood
13. What is the kidney that functions at the interim kidney in the 1st trimester? What does it later contribute to?
Mesonephros; male genital system
hypospadias
Found in lateral neck; from no obliteration of 2-4th clefts
When the AP septum meets and fuses with the muscular ventricular septum to form membranous intraventricular septum - closing interventricular foramen
14. what else is the caudal regression known as? What two teratogen can cause this in the fetus?
Before getting pregnant!
VACTERL; OCPs and maternal diabetes
primary palate
mesoderm
15. What happens in pancreas divisum? what results?
3rd and 4th arches
Neural plate; closes by week 4
Ventral and dorsal parts fail to fuse at 8th week; 2 pancreatic ducts!- more prone to pancreatitis
Bulbos Cordis; right ventricle entirely
16. what structures are the derivatives of the neural crest cells in branchial arches?
Prosencephalon - mesencephalon - rhombencephalon
Bone/cartilage and nerves
Thickened ectoderm at end of each developing limb
septum primum and/or secundum
17. What is an example of a syndrome that can cause abnormal neural crest migration and thus CV abnormalities?
No more umbilical circulation emptying into RA
Medial palatine processes
Neuroectoderm
DiGeorge
18. What is the most common autopsy finding in brains of premature infants?
Urachus/median umbilical ligament; bladder and yolk sac
Neuroectoderm
Muscles and arteries
Germinal matrix hemorrhage
19. What axis does the basal plate form? what neural system does it become?
Fallopian tube - uterus - upper 1/3 of vagina
Week 8
Ventral ; motor
4th/5th branchial pouches
20. 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?
Arnold Chiari and Dandy Walker; Arnold Chiari; Dandy Walker; Arnold Chiari
Urogenital sinus; wolffian duct; mullerian duct; urogenital sinus; wolffian duct; wolffian duct; mullerian; mullerian
6-30
Failure of the urachus to obliterate
21. What does the mullerian duct develop into? wollffian?
Failure to recanalize; 21
...
Fallopian tube - uterus - upper 1/3 of vagina
Increase in oxygen concentration which decreases prostaglandin concentration
22. Before birth - blood entering the LA is less than...
Urachus/median umbilical ligament; bladder and yolk sac
Day 6; with implantation
blood entering the RA
Cerebral hemisphere - thalami
23. From What embryonic layer is the spleen from?
IMA
Mesoderm
Ventral ; motor
Surface ectoderm
24. What is the defect in spina bifida occulta? is there any structural herniation? where on the spinal cord is it usually seen?
Failure of bony spinal canal to fuse; no; lower vertebral levels
Decidual basalis
Tongue
Valproate acid
25. When is most important to take folic acid to prevent neural tube defects?
Meckels cartilage: mandible - malleus - INCUS - sphenoMandibular ligament; CN V2 and V3
Uretopelvis; most common site for obstruction (hydronephrosis) in fetus
Incomplete fusion of paramesonephric ducts; UT abnormalities and infertility
Before getting pregnant!
26. What are the two types of posterior fossa malformations? which one results in a hindbrain crowding? and which results in an enlarged posterior fossa? which one is associated with syringomelia?
Arnold Chiari and Dandy Walker; Arnold Chiari; Dandy Walker; Arnold Chiari
Neural crest development; MEN 2A (pheo - PTH tumor - parafollicular cell tumor)
Amniotic cavity and yolk sac
Excessive resorption of septum primum or secondum (or both)
27. What does the ureteric bud interact with and What does it induce it to become?
Metanephric mesenchyme; differentiation and formation of glomerulus and renal tubules to distal convoluted tubule
SRY gene on Y chromosomes; sertoli and leydi; MIF and androgens; suppression of paramesonephric ducts and dev. of mesonephric (all respectively)
Sonic Hedgehog
Week 4; week 3
28. what junction is the last to canalize? what implications does this have down the line?
Uretopelvis; most common site for obstruction (hydronephrosis) in fetus
Alkylating agents
During; instrinsic
Skewed development of AP septum
29. Which branchial apparatus develops into the thymus?
Base of limbs in the zone of polarizing activity; ant - post
3rd pouch
Outgrowth of mesonephric as ureteric bud; most caudal
Week 4; week 3
30. From what aortic arch does the stapedial artery arise? the hyoid?
2nd; 2nd
Synctiotrophoblast; outer; no
From the the lung; blood from SVC that went into RV gets shunted from pulm artery to aorta; ligamentum arteriosum
Decreases
31. What causes the decrease in Right atrial pressure to close the fossa ovale?
Alkylating agents
Congenital and chromosomal abnormalities
No more umbilical circulation emptying into RA
XII
32. What does DHT turn the urogenital folds into? estrogen?
Neural crest cells
Base of limbs in the zone of polarizing activity; ant - post
Pataus; fetal alcohol syndrome
Ventral shaft of penis (penile urethra); labia minora
33. For what reason do hypospadias need to be fixed?
All 3
Pulm art (prox) and ductus arteriosus
Prevent recurrent UTIs
Endoderm
34. From What embryonic layer does the spinal cord arise?
During; instrinsic
3rd and 4th arches
5th
Neuroectoderm
35. What is used to keep the PDA open?
Mental retardation - holoprosencephaly - facial features - fistulas
Prostaglandins
Decreased pulmonary resistance in the pulmonary vasculature
Myelencephalon
36. What are the three regions of the brain (in order of cranial to caudal)?
VACTERL- vertebral defect - anal atresia - cardiac defects - tracheo - esophageal fistula - renal defects - limb defects
Decreased separation of hemispheres across midline; cyclopia
lumbosacral
Prosencephalon - mesencephalon - rhombencephalon
37. How do you differentiate a thyroglossal duct cyst from a persistent cervical sinus?
Nutrient and gas for exchange; endometrium
Thyroglossal duct cysts will move with swallowing while persistent cervical sinuses in lateral neck wont
Pronephros - mesonephros - metanephros; pronephros; most cranially
3
38. How does annular pancreas present in children?
Congenital and chromosomal abnormalities
Gastric outlet obstruction (bilious vomiting - feeding intolerance - abdominal distention)
Diencephalon
Arnold Chiari and Dandy Walker; Arnold Chiari; Dandy Walker; Arnold Chiari
39. From What embryonic layer does connective tissue and muscle arise?
Mesoderm
Absent cerebellar vermis; cystic enlargement of 4th ventricle
Day 6; with implantation
Week 2; bilaminar disk; epiblast and hypoblast
40. What are two common findings in pyloric stenosis?
Palpable olive mass in epigastric region; nonbilious projectile vomitting @around 2 weeks
IX; X
Hypertrophy of muscularis externis of pylorus; surgical incision
Embryonic period; 1st trimester
41. Which branchial apparatus develops into the inferior parathyroids?
Maxillary and medial nasal processes
Wolffian; mullerian
Surface ectoderm
3rd pouch
42. What is germinal matrix hemorrhage associated with?
Telencephalon
Respiratory distress syndrome
DES
T neuroectoderm
43. From what region does the midbrain form from?
Mesencephalon
Prostaglandins
Ventral and dorsal parts fail to fuse at 8th week; 2 pancreatic ducts!- more prone to pancreatitis
Oxygenated; placenta to fetus (IVC)
44. From What embryonic layer is aorticopulmonary septum from ?
Neural crest cells
Cerebral hemisphere - thalami
SRY gene on Y chromosomes; sertoli and leydi; MIF and androgens; suppression of paramesonephric ducts and dev. of mesonephric (all respectively)
Surface ectoderm
45. From where is the pancreas derived? the spleen?
Foregut; dorsal mesentery (mesodermal)
Indomethacin; blocks PG production
Neural plate; closes by week 4
Persistent connection between amniotic cavity and spinal canal; low folic acid
46. What artery is derived branchial (aortic) arch 4?
Prosencephalon
VACTERL; OCPs and maternal diabetes
Fetal kidney; fetal swallows - absorbs - and then removed from placental blood
Aortic arch and prox part of subclavian
47. What is hypoplasia? is primordial tissue present?
Incomplete; yes
Aortic arch (from left side); right subclavian (on the right)
Right horn of the SV
No more umbilical circulation emptying into RA
48. What secretes hCG?
Turners; inferior
Branchial arch 2
Ionizing
Synctiotrophoblast
49. Which cranial nerve innervates the motor function of the tongue?
XII
Failure to recanalize; 21
The caudal end mesonephros; the ureter - pelvis - calyces - collecting ducts
6-30
50. From What embryonic layer are the pia and arachnoid from?
Neural crest cells
Nicotine; preterm labor
Neuroectoderm
LH