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. From where does the signal come from to suppress paramesonephric ducts? what stimulates development of the mesonephric ducts?
Week 4; week 3
Mullerian inhibitory factor from Sertoli cells; increased androgen from Leydig cells
Persistence of 3rd cleft (groove) and pouch causes fistula between tonsillar area and cleft in lateral neck
80%
2. What artery is derived branchial (aortic) arch 6?
Pulm art (prox) and ductus arteriosus
20-50yrs - Abdominal pain - Postprandial fullness - Nausea - Peptic ulcers - Pancreatitis - Rarely - biliary obstruction
Ectoderm; endoderm
Respiratory distress syndrome
3. Cleft lip is a failure of fusion of ________ and ______.
Surface ectoderm
Blastocyst; epiblast and hypoblast; synctiotrophoblast and cytotrophoblast
Maxillary and medial nasal processes
Hypospadias
4. What separates the ant 1/3 and post 2/3 of tongue?
Foramen cecum and terminal sulus
Week 4; week 3
Bones - cartilage - and nerves
Amniotic epithelium
5. What is the primitive streak? From what layer does it form?
Mesoderm; epiblast
Mesoderm
Week 2; bilaminar disk; epiblast and hypoblast
Diencephalon
6. Where is sonic hedgehog gene produced? What axis is it responsible in patterning?
Oxygenated; placenta to fetus (IVC)
Neural crest cells
VSD
Base of limbs in the zone of polarizing activity; ant - post
7. What produces testis determining factor? what cells are produced from this? and What do they secrete? does this result in?
Deoxygenated blood; fetal internal iliac arteries to placenta
Maternally derived; meconium
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)
8. What is the physiological herniation that occurs at the 6th week - what herniates out of the umbilical ring? when it comes back in the 10th week - What does it rotate around?
Week 10-12; end of 1st trimester
Mesencephalon
Ventral; failure of urogenital folds to close
Umbilical - midgut herniates through umbilical ring; SMA
9. From What embryonic layer is the eustachian tube from?
Decidual basalis
Absent cerebellar vermis; cystic enlargement of 4th ventricle
Mesoderm
secondary palate
10. What does the ureteric bud interact with and What does it induce it to become?
IMA
Arnold Chiari and Dandy Walker; Arnold Chiari; Dandy Walker; Arnold Chiari
Metanephric mesenchyme; differentiation and formation of glomerulus and renal tubules to distal convoluted tubule
Obliterated; forms tunica vaginalis
11. What causes the degeneration of the spinal cord in syringomelia?
Fetal alcohol syndrome; mental retardation
Fluid filled syrinx causes expansion and degeneration of cord tracts
Right common cardinal vein and right anterior cardinal vein
Where the epiblast and hypoblast fuse
12. From What embryonic layer does the parathyroid arise ?
Urogenital sinus; wolffian duct; mullerian duct; urogenital sinus; wolffian duct; wolffian duct; mullerian; mullerian
Endoderm
1st
not covered
13. From where is amniotic fluid produced? other than electrolytes and carbs - what else does it contain?
Thyroglossal duct; persists as pyramidal lobe of thyroid; foramen cecum on tongue is normal remnant of thyroglossal duct
Maternally derived; meconium
Endoderm lined structures of ear: middle ear cavity - eustacian tube - mastoid air cells
Decreased separation of hemispheres across midline; cyclopia
14. what bone/cartilage and nerves are derived from branchial arch 3?
Palpable olive mass in epigastric region; nonbilious projectile vomitting @around 2 weeks
4th/5th branchial pouches
Neural plate; closes by week 4
Greater horn of hyoid; CN IX (styloPharyngeus)
15. Which part of the chorionic villi can make cells?
Cytotrophoblast
Ionizing
Umbilical artery - vein; and whartons jelly (mucus connective tissue) - urachus
Mesoderm
16. Cleft palate is a failure of fusion of the lateral palatine processes - the nasal septum and or the ________?
Ampulla
Medial palatine processes
Folate antagonists
3rd pouch
17. The spleen is ____________ in origin and supplied by a foregut artery
Failure to recanalize; 21
Palpable olive mass in epigastric region; nonbilious projectile vomitting @around 2 weeks
mesodermal
Surface ectoderm
18. What is the allantois become? What is this duct connected to ( on both ends)?
Amniotic cavity and yolk sac
Branchial arch 2
Urachus/median umbilical ligament; bladder and yolk sac
Week 4; week 3
19. What teratogens can cause flipper limbs (limb defects)? What is this drug used for?
Neural crest cells
Hepatic circulation; ligamentum venosum
Thalidomide; nausea
Endoderm
20. Where is erythropoeisis in the weeks 3-8 of fetal development? Where does it occur after that? until when?
Neural crest migration - they then cause spiral
Decidual basalis
Yolk sac; liver (weeks 6-30) and spleen (9-28 weeks)
Week 3-8
21. What two things cause VACTERL syndrome?
DHT; estrogen
3
OCPS and maternal diabetes
Medial palatine processes
22. What results in annular pancreas? How does it happen?
Decreased pulmonary resistance in the pulmonary vasculature
Ring of pancreatic tissue can cause duodenal narrowing; ventral pancreatic bud abnormally encircles 2nd part of duodenum
Synctiotrophoblast; outer; no
Upper 1/3; urogenital sinus
23. Which branchial apparatus derivative makes the tympanic membrane of the ear?
Membrane - all 3 from 1st appartus
DES
Temporary cervical sinus
Thyroglossal duct; persists as pyramidal lobe of thyroid; foramen cecum on tongue is normal remnant of thyroglossal duct
24. What causes persistent Truncus Arteriosus? What does it result in?
Partial AP septum development; one large vessel leaves the heart - Right to left shunt
4th week
Failure of bony spinal canal to fuse; no; lower vertebral levels
VACTERL; OCPs and maternal diabetes
25. From what are the umbilical arteries and veins derived from?
Allantois
StyloPharyngeus
Excessive resorption of septum primum or secondum (or both)
Found in lateral neck; from no obliteration of 2-4th clefts
26. From what region of the brain does the aqueduct form?
mesoderm
Mesoderm
Rhombencephalon
Polyhydramnios - Down syndrome - Esophageal/duodenal atresia - Imperforate anus - Meckel diverticulum
27. From what aortic arch does the first part of the maxillary artery arise?
1st
Neuroectoderm
When left to right shunting switching to right to left shunting
Rhombencephalon
28. What is associated with only one umbilical artery?
80%
Vascular accident intra uterine; apple peel atresia
Congenital and chromosomal abnormalities
3rd pouch
29. From where is the pancreas derived? the spleen?
Foregut; dorsal mesentery (mesodermal)
Mullerian inhibitory factor from Sertoli cells; increased androgen from Leydig cells
First branchial pouch
Most pharyngeal constrictors - Cricothyroid - levator veli palatini; CN X (superior laryngeal branch - swallowing)
30. By what week is the neural tube supposed to be closed? when did it start forming?
Bilateral loss of pain and temperature sensation in upper extremities with preservation of touch sensation
Week 4; week 3
Surface ectoderm
Increase in oxygen concentration which decreases prostaglandin concentration
31. Which CN accounts for the anterior 2/3 of the tongues sensation and pain? how about taste?
V3; VII
Nutrient and gas for exchange; endometrium
...
20-50yrs - Abdominal pain - Postprandial fullness - Nausea - Peptic ulcers - Pancreatitis - Rarely - biliary obstruction
32. what bone/cartilage and nerves are derived from branchial arch 2?
Endoderm
Surface ectoderm
Reicherts cartilage: Stapes - Styloid process - Lesser horn of hyloid - Stylohyoid ligament and CN VII
Branchial arch 2
33. Which arches form the posterior 1/3 of the tongue?
Gastric outlet obstruction (bilious vomiting - feeding intolerance - abdominal distention)
SRY gene on Y chromosomes; sertoli and leydi; MIF and androgens; suppression of paramesonephric ducts and dev. of mesonephric (all respectively)
Arches 3 and 4
Deformation
34. 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?
Urogenital sinus; wolffian duct; mullerian duct; urogenital sinus; wolffian duct; wolffian duct; mullerian; mullerian
Epiblast
Endometrium
Dorsal and ventral buds
35. What is hypoplasia? is primordial tissue present?
VSD
8
Incomplete; yes
Medial palatine processes
36. From What embryonic layer does the epithelial linings of the oral cavity arise?
ACE inhibitors - HCTZ
Foregut; dorsal mesentery (mesodermal)
Surface ectoderm
Maxillary and medial nasal processes
37. From What embryonic layer do the ANS arise?
Where the epiblast and hypoblast fuse
Neural crest cells
Metencephalon; cerebellum
Tongue
38. What does DHT turn the labioscrotal swelling into? estrogen?
Midgut; 10th week
Surface ectoderm
Scrotum; labia majora
Week 10-12; end of 1st trimester
39. What is another name for the mesonephric duct? paramesonephric?
Week 8
Decreased pulmonary resistance in the pulmonary vasculature
Wolffian; mullerian
Found in lateral neck; from no obliteration of 2-4th clefts
40. During what months is the fetus most susceptible to teratogens? What trimester?
Upper 1/3; urogenital sinus
Embryonic period; 1st trimester
6-30
Tongue
41. 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
Neuroectoderm
Thyroglossal duct; persists as pyramidal lobe of thyroid; foramen cecum on tongue is normal remnant of thyroglossal duct
Female; paramesonephric; mesonephric
42. Which CN allows for taste and sensation in the posterior 1/3 of the tongue? how about the very back ?
IX; X
Deformation
80%
Bones - cartilage - and nerves
43. As a horseshoe kidney ascends during kidney development - What do they get trapped under?
LH
IMA
Obliterated; forms tunica vaginalis
1st arch neural crest fails to migrate --> mandibular hypoplasia - facial abnormalities (cleft palate - decreased slanting of palpebral fissures)
44. Before birth - blood entering the LA is less than...
Surface ectoderm
Surface ectoderm
blood entering the RA
Oxygenated; placenta to fetus (IVC)
45. From What embryonic layer do the parafollicular cells of the thyroid arise?
Neural crest cells
2nd pouch
Initial left to right shunting - then switches
Neuroectoderm
46. What does DHT turn the urogenital folds into? estrogen?
Foregut; dorsal mesentery (mesodermal)
4th pouch
Ventral shaft of penis (penile urethra); labia minora
Membrane - all 3 from 1st appartus
47. What artery is derived branchial (aortic) arch 1?
Maxillary
2nd; 2nd
Endoderm
Pronephros - mesonephros - metanephros; pronephros; most cranially
48. In order to survive tricuspid atresia - What do you need?
VSD
80%
Medial palatine processes
Fluid filled cavity in spinal cord; C8- T1; arnold chiari II
49. From What embryonic layer is the bladder and urethra from?
Physiologic incomplete muscular ventricular septum
Mesoderm
From teh lung;blood from IVC in RA to LA; fossa ovalis
Ventral; failure of urogenital folds to close
50. in hypospadias - on which side is the abnormal opening? What causes it?
Week 4
Dorsal and ventral buds
Ventral; failure of urogenital folds to close
Common carotid and internal carotid