SUBJECTS
|
BROWSE
|
CAREER CENTER
|
POPULAR
|
JOIN
|
LOGIN
Business Skills
|
Soft Skills
|
Basic Literacy
|
Certifications
About
|
Help
|
Privacy
|
Terms
|
Email
Search
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. Only _______________________________ are associated with neural tube defects
Prostaglandins
VACTERL- vertebral defect - anal atresia - cardiac defects - tracheo - esophageal fistula - renal defects - limb defects
arnold chiari associated with thoraclumbar myelomeningocele
Synctiotrophoblast
2. What axis does the basal plate form? what neural system does it become?
Wolffian; mullerian
Ventral ; motor
Ventral; failure of urogenital folds to close
Foramen cecum and terminal sulus
3. Which branchial derivative accounts for the posterior 2/3 of the tongue?
Post. sup wall; luteal phase
3rd and 4th arches
Thyroglossal duct; persists as pyramidal lobe of thyroid; foramen cecum on tongue is normal remnant of thyroglossal duct
From the the lung; blood from SVC that went into RV gets shunted from pulm artery to aorta; ligamentum arteriosum
4. What is the initial step to interventricular septum development? is it complete?
lumbosacral
Deoxygenated blood; fetal internal iliac arteries to placenta
A vitelline fistula - failure of vitelline duct to close
Muscular ventricular septum; no
5. From What embryonic layer is the spleen from?
Mesoderm
Ventral shaft of penis (penile urethra); labia minora
Nicotine; preterm labor
Bilateral loss of pain and temperature sensation in upper extremities with preservation of touch sensation
6. What is the homeobox gene responsible in developing? (What axis)
5th
Week 2; bilaminar disk; epiblast and hypoblast
Cranio - caudal; segmental
Persistence of 3rd cleft (groove) and pouch causes fistula between tonsillar area and cleft in lateral neck
7. Which branchial apparatus develops into the inferior parathyroids?
3rd pouch
Muscles and arteries
DiGeorge
Endoderm lined structures of ear: middle ear cavity - eustacian tube - mastoid air cells
8. What type of - amnios does bilateral agenesis form? What three symptoms does this cause?
Neural plate; closes by week 4
Oligohydramnios
Prostaglandins
secondary palate
9. What gene is produced in the zone of polarizing activity?
Mesoderm
Outgrowth of mesonephric as ureteric bud; most caudal
Muscles of facial expression - stapedius - stylohyoid - posterior belly of the digastric
Sonic Hedgehog
10. Which cranial nerve innervates the motor function of the tongue?
Thyroglossal duct; persists as pyramidal lobe of thyroid; foramen cecum on tongue is normal remnant of thyroglossal duct
SRY gene on Y chromosomes; sertoli and leydi; MIF and androgens; suppression of paramesonephric ducts and dev. of mesonephric (all respectively)
Week 4
XII
11. From where do the three different kidneys come from? Which is the earliest one? is it located most cranially or caudally?
hypertrophy
ACE inhibitors - HCTZ
Pronephros - mesonephros - metanephros; pronephros; most cranially
Most pharyngeal constrictors - Cricothyroid - levator veli palatini; CN X (superior laryngeal branch - swallowing)
12. Other than not having a brain - what else is a symptom of anencephaly? why? hint: think about amniotic fluid
Allantois
3rd and 4th arches
Cleft lip/palate
Polyhydramnios
13. What is holoprosencephaly? what eye disorder does it result in?
Mid gut to yolk sac; omphalomesenteric duct; 7th week
Thickened ectoderm at end of each developing limb
Hypertrophy of muscularis externis of pylorus; surgical incision
Decreased separation of hemispheres across midline; cyclopia
14. what closes the ductus arteriousus?
3rd; proximal part of the internal carotid artery
Oxygenated; placenta to fetus (IVC)
Increase in oxygen concentration which decreases prostaglandin concentration
Bones - cartilage - and nerves
15. What connects the thyroid to the tongue? when happens if it doesnt obliterate?
Caused by compression on trocheal nerve - causes vertical gaze paralysis (associated with arnold chiari)
Greater horn of hyoid; CN IX (styloPharyngeus)
Thyroglossal duct; persists as pyramidal lobe of thyroid; foramen cecum on tongue is normal remnant of thyroglossal duct
Common carotid and internal carotid
16. What hormone is hcG structurally similar too?
Neuroectoderm
LH
Obliterated; forms tunica vaginalis
Base of limbs in the zone of polarizing activity; ant - post
17. Where is the apical ectodermal ridge?
Incomplete fusion of paramesonephric ducts; UT abnormalities and infertility
Neural crest cells
Thickened ectoderm at end of each developing limb
Mesoderm
18. What type of radiation is teratogenic ?
No more umbilical circulation emptying into RA
mesodermal
Ionizing
During; instrinsic
19. From What embryonic layer do the astrocytes arise?
Nicotine; preterm labor
Mesoderm; epiblast
Neural crest cells
Neuroectoderm
20. what else is the caudal regression known as? What two teratogen can cause this in the fetus?
Membrane - all 3 from 1st appartus
VACTERL; OCPs and maternal diabetes
Alkylating agents
pyloric stenosis
21. What is duodenal atresia usually due to? What trisomy is it most often seen in?
Neural crest cells
Failure to recanalize; 21
Palpable olive mass in epigastric region; nonbilious projectile vomitting @around 2 weeks
Hepatic circulation; ligamentum venosum
22. what chemo drugs can cause neural tube defects in the fetus?
Endoderm - floor of primitive pharynx
Lots - cleft palate/lip
Folate antagonists
Yolk sac; 3rd week
23. What is another name for the mesonephric duct? paramesonephric?
Wolffian; mullerian
Neural crest migration - they then cause spiral
Fallopian tube - uterus - upper 1/3 of vagina
Neuroectoderm
24. Where does the blastocyst implant in the uterus? During what phase of the menstrual cycle?
4th week
Failure of the urachus to obliterate
Hepatic circulation; ligamentum venosum
Post. sup wall; luteal phase
25. What does the mullerian duct develop into? wollffian?
Fallopian tube - uterus - upper 1/3 of vagina
XII
Metencephalon; cerebellum
Week 3-8
26. From What embryonic layer does the retina arise?
Arnold Chiari and Dandy Walker; Arnold Chiari; Dandy Walker; Arnold Chiari
Neuroectoderm
Indomethacin; blocks PG production
DES
27. what muscles are derived from branchial arch 2?
After; extrinsic
Thyroid - cricoid - arytenoids - corniculate cuneiform
Muscles of facial expression - stapedius - stylohyoid - posterior belly of the digastric
1st branchial arch
28. Where is sonic hedgehog gene produced? What axis is it responsible in patterning?
All 3
Base of limbs in the zone of polarizing activity; ant - post
IMA
2nd; 2nd
29. What produces testis determining factor? what cells are produced from this? and What do they secrete? does this result in?
Female; paramesonephric; mesonephric
3rd pouch
SRY gene on Y chromosomes; sertoli and leydi; MIF and androgens; suppression of paramesonephric ducts and dev. of mesonephric (all respectively)
Endoderm
30. Which is more common - epispadias or hypospadias?
Skewed development of AP septum
Hypospadias
Cleft lip/palate
Polyhydramnios
31. What artery is derived branchial (aortic) arch 1?
Maxillary and medial nasal processes
Mullerian inhibitory factor from Sertoli cells; increased androgen from Leydig cells
Aortic arch and prox part of subclavian
Maxillary
32. What components do the neural crest cells of the branchial arches give rise to?
Surface ectoderm
Bones - cartilage - and nerves
Endoderm
Umbilical artery - vein; and whartons jelly (mucus connective tissue) - urachus
33. What trisomy is associated with holoprosencephaly? What teratogen?
Upper 1/3; urogenital sinus
Ventral bud
Pataus; fetal alcohol syndrome
Neural crest cells
34. What embryologic structure gives rise to the smooth outflow tracts of the ventricles? what else does it give rise to?
Bulbos Cordis; right ventricle entirely
DES
Initial left to right shunting - then switches
Most pharyngeal constrictors - Cricothyroid - levator veli palatini; CN X (superior laryngeal branch - swallowing)
35. What does the first cleft/groove of the branchial apparatus develop into?
Ovarian ligament and round ligament of uterus; anchors testes within scrotum
Yolk sac; liver (weeks 6-30) and spleen (9-28 weeks)
Stapedius and hyoid artery
External auditory meatus
36. What type of blood do umbilical veins carry? From where to where?
Oxygenated; placenta to fetus (IVC)
Hypospadias
Foregut; dorsal mesentery (mesodermal)
Annular pancrease
37. what structures are the derivatives of the neural crest cells in branchial arches?
Fetal kidney; fetal swallows - absorbs - and then removed from placental blood
Ventral and dorsal parts fail to fuse at 8th week; 2 pancreatic ducts!- more prone to pancreatitis
A vitelline fistula - failure of vitelline duct to close
Bone/cartilage and nerves
38. What do the groove/clefts of the branchial apparatus correlate to?
Absent cerebellar vermis; cystic enlargement of 4th ventricle
Sperm plus egg
Polyhydramnios - Down syndrome - Esophageal/duodenal atresia - Imperforate anus - Meckel diverticulum
Ectoderm
39. What embryologic structure provides the aorticpulmonary septum?
Neural crest migration - they then cause spiral
Duodenum to transverse colon; distal transverse colon to rectum
Neural crest cells
Surface ectoderm
40. On what side is the abnormal opening in epispadias? What causes it?
Surface ectoderm
Dorsal; faulty positioning of genital tubercle
Medial palatine processes
Endoderm lined structures of ear: middle ear cavity - eustacian tube - mastoid air cells
41. When is most important to take folic acid to prevent neural tube defects?
When left to right shunting switching to right to left shunting
Urogenital sinus; wolffian duct; mullerian duct; urogenital sinus; wolffian duct; wolffian duct; mullerian; mullerian
Before getting pregnant!
Mesoderm
42. What is hypoplasia? is primordial tissue present?
20-50yrs - Abdominal pain - Postprandial fullness - Nausea - Peptic ulcers - Pancreatitis - Rarely - biliary obstruction
Incomplete; yes
Caused by compression on trocheal nerve - causes vertical gaze paralysis (associated with arnold chiari)
SRY gene on Y chromosomes; sertoli and leydi; MIF and androgens; suppression of paramesonephric ducts and dev. of mesonephric (all respectively)
43. What teratogen can cause an absence of digits amongst other things in the fetus? give an example.
Lots - cleft palate/lip
...
A vitelline fistula - failure of vitelline duct to close
Alkylating agents
44. What is the female remnant of processus vaginalis? male remnant?
mesodermal
Surface ectoderm
Obliterated; forms tunica vaginalis
Foramen cecum and terminal sulus
45. What are the three regions of the brain (in order of cranial to caudal)?
Apical ectodermal ridge; limb lengthening; stimulates mitosis of underlying mesoderm
Surface ectoderm
Prosencephalon - mesencephalon - rhombencephalon
Tunica vaginalis not fully fused
46. Which CN allows for taste and sensation in the posterior 1/3 of the tongue? how about the very back ?
Germinal matrix hemorrhage
IX; X
Yolk sac; liver (weeks 6-30) and spleen (9-28 weeks)
Allantois
47. What does the ductus venosus shunt blood away from? What is its remnant?
Epiblast
Amniotic cavity and yolk sac
Cytotrophoblast
Hepatic circulation; ligamentum venosum
48. When does erythropoeisis begin in the bone marow?
Failure to spiral (aorta coming out of RV and PA coming out of left ventricle)- two completely separate systems
not covered
28 week onward
The caudal end mesonephros; the ureter - pelvis - calyces - collecting ducts
49. What day is the amnion formed?
Maxillary and medial nasal processes
8
Thyroid - cricoid - arytenoids - corniculate cuneiform
Mesdoerm
50. What causes meconium discharge from the umbilicus?
A vitelline fistula - failure of vitelline duct to close
OCPS and maternal diabetes
6th aortic arch
Mesoderm