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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 is the female remnant of processus vaginalis? male remnant?
Obliterated; forms tunica vaginalis
Mesoderm
Outgrowth of mesonephric as ureteric bud; most caudal
Surface ectoderm
2. From where did a branchial cleft cyst arise if it found?
Endoderm
Week 10-12; end of 1st trimester
Ring of pancreatic tissue can cause duodenal narrowing; ventral pancreatic bud abnormally encircles 2nd part of duodenum
Found in lateral neck; from no obliteration of 2-4th clefts
3. From What embryonic lare are the odontoblasts from?
Neural crest cells
Stapedius and hyoid artery
From the the lung; blood from SVC that went into RV gets shunted from pulm artery to aorta; ligamentum arteriosum
Week 10-12; end of 1st trimester
4. Does deformation occur during or after the embryonic period? is it due to an extrinsic or intrinsic disruption?
lumbosacral
Dorsal; sensory
can make cells
After; extrinsic
5. From where does the permanent kidney for? is it most caudal or most cranial?
Neural crest cells
Outgrowth of mesonephric as ureteric bud; most caudal
Bone/cartilage and nerves
Lots - cleft palate/lip
6. What are the three regions of the brain (in order of cranial to caudal)?
Prosencephalon - mesencephalon - rhombencephalon
Apical ectodermal ridge
Bones - cartilage - and nerves
Aortic arch (from left side); right subclavian (on the right)
7. When does the blastocyst split into two disks? What is this disk called? What are the two germ layers called?
Week 2; bilaminar disk; epiblast and hypoblast
VSD
Endocardial cushions
3rd; proximal part of the internal carotid artery
8. What part of the fetal comp of the placenta secretes hCG? is this part on the inner or outer layer of the chorionic villi? does it make cells?
Ebsteins anomaly; tricuspid atresia
Arnold Chiari and Dandy Walker; Arnold Chiari; Dandy Walker; Arnold Chiari
Rhombencephalon
Synctiotrophoblast; outer; no
9. What embryological structures give rise to the SVC?
Epispadias
Ventral bud
Right common cardinal vein and right anterior cardinal vein
Surface ectoderm
10. From where is the pancreas derived? the spleen?
Maxillary and medial nasal processes
Mesoderm
Turners; inferior
Foregut; dorsal mesentery (mesodermal)
11. what separates the atria from the ventricles?
T neuroectoderm
Ectoderm
Endocardial cushions
Mesdoerm
12. What is the primitive streak? From what layer does it form?
Day 6; maintains corpus luteum; 1st trimester
Neural crest migration - they then cause spiral
Mesoderm; epiblast
Thyroglossal duct cysts will move with swallowing while persistent cervical sinuses in lateral neck wont
13. What hormone is hcG structurally similar too?
OCPS and maternal diabetes
Endoderm - floor of primitive pharynx
They are the edge of neural plate folding; all over the body
LH
14. What causes a large posterior fossa in a dandy walker malformation? What is found in this fossa?
Pronephros - mesonephros - metanephros; pronephros; most cranially
Valproate acid
Absent cerebellar vermis; cystic enlargement of 4th ventricle
Surface ectoderm
15. Which cranial nerve innervates the motor function of the tongue?
XII
Sonic Hedgehog
Bones - cartilage - and nerves
Neural crest cells
16. What does the midgut form? hindgut?
Duodenum to transverse colon; distal transverse colon to rectum
2; 1
Arches 3 and 4
Day 6; maintains corpus luteum; 1st trimester
17. From What embryonic layer does the skin dermis arise?
Mesoderm
DES
Metencephalon; cerebellum
XII
18. What is DiGeorge syndrome and What does it result in?
Reicherts cartilage: Stapes - Styloid process - Lesser horn of hyloid - Stylohyoid ligament and CN VII
Aberrant development of 3rd and 4th pouches; t cell def (thymic aplasia) - hypocalcemia (failure of parathyroid development) - CF and CV defects
Before getting pregnant!
V3; VII
19. 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
Pataus; fetal alcohol syndrome
Fetal alcohol syndrome; mental retardation
Persistence of 3rd cleft (groove) and pouch causes fistula between tonsillar area and cleft in lateral neck
20. What is perinauds syndrome?
ACE inhibitors - HCTZ
5th
Caused by compression on trocheal nerve - causes vertical gaze paralysis (associated with arnold chiari)
Ectoderm
21. what results if they dont? What can increase the risks of this?
2nd; 2nd
Persistent connection between amniotic cavity and spinal canal; low folic acid
Rhombencephalon
External auditory meatus
22. From what region of the brain does the lateral ventricles and the 3rd ventricle form?
Prosencephalon
Fetal kidney; fetal swallows - absorbs - and then removed from placental blood
hypospadias
Mesoderm
23. What causes the increase in left atrial pressure to close the fossa ovale?
From teh lung;blood from IVC in RA to LA; fossa ovalis
Primitive atrium
Surface ectoderm
Decreased pulmonary resistance in the pulmonary vasculature
24. What teratogen can cause inhibition of intestinal folate absorption and thus neural tube defects?
Bulbourethral glands (of Cowper) and Prostate gland; greater vestibular glands (of Bartholin) and Urethral and paraurethral glands (of Skene)
Embryonic period; 1st trimester
Valproate acid
Increased AFP and acetycholinesterase (not ACh!) in CSF
25. From where to Where is the foregut derivative? midgut? hindgut?
Vascular accident intra uterine; apple peel atresia
Yolk sac; 3rd week
Pharynx to duodenum; duodenum to transverse colon; distal transverse colon to rectum
Ectoderm - mesoderm - endoderm; epiblast - primitive streak - hypoblast; week 3
26. Which part of the chorionic villi can make cells?
Common carotid and internal carotid
Cytotrophoblast
Cerebral hemisphere - thalami
Surface ectoderm
27. What results in annular pancreas? How does it happen?
not covered
Wolffian; mullerian
Bilateral loss of pain and temperature sensation in upper extremities with preservation of touch sensation
Ring of pancreatic tissue can cause duodenal narrowing; ventral pancreatic bud abnormally encircles 2nd part of duodenum
28. What causes the obstruction in pyloric stenosis? treatment?
2nd; 2nd
Tunica vaginalis not fully fused
During; instrinsic
Hypertrophy of muscularis externis of pylorus; surgical incision
29. 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?
Most pharyngeal constrictors - Cricothyroid - levator veli palatini; CN X (superior laryngeal branch - swallowing)
Endoderm lined structures of ear: middle ear cavity - eustacian tube - mastoid air cells
Umbilical - midgut herniates through umbilical ring; SMA
Prostaglandins
30. Most myelomeningoceles present in the _______ region
Germinal matrix hemorrhage
T neuroectoderm
Incomplete fusion of paramesonephric ducts; UT abnormalities and infertility
lumbosacral
31. From what aortic arch does the first part of the maxillary artery arise?
Surface ectoderm
1st
Branchial arch 2
Prostaglandins
32. From What do the embryoblast and trophoblast form from? What does the embryoblast split into? the trophoblast?
From teh lung;blood from IVC in RA to LA; fossa ovalis
Blastocyst; epiblast and hypoblast; synctiotrophoblast and cytotrophoblast
not covered
Surface ectoderm
33. From what region of the brain does the fourth ventricle form?
Rhombencephalon
Nicotine; preterm labor
Persistent connection between amniotic cavity and spinal canal; low folic acid
Wolffian; mullerian
34. What happens in pancreas divisum? what results?
Membrane - all 3 from 1st appartus
Surface ectoderm
No organ in each; agenesis no primordial tissue
Ventral and dorsal parts fail to fuse at 8th week; 2 pancreatic ducts!- more prone to pancreatitis
35. From What embryonic layer does the gut tube epithelium arise?
Bone/cartilage and nerves
Obliterated
Neural crest cells
Endoderm
36. What components do the mesoderm of the branchial arches give rise to?
Respiratory distress syndrome
Mesoderm
2; 1
Muscles and arteries
37. During what months is the fetus most susceptible to teratogens? What trimester?
First branchial pouch
Neural crest cells
Embryonic period; 1st trimester
Decidual basalis
38. what bone/cartilage and nerves are derived from branchial arch 1?
1st
Meckels cartilage: mandible - malleus - INCUS - sphenoMandibular ligament; CN V2 and V3
Week 8
Neuroectoderm
39. In both meningocele and myelomeningocele the dura...
Stapedius and hyoid artery
Week 8
6th aortic arch
is no longer intact
40. When does hcG get secreted? What does it do?up until when ?
Day 6; maintains corpus luteum; 1st trimester
Lots - cleft palate/lip
A vitelline fistula - failure of vitelline duct to close
Mesoderm
41. From What embryonic layer do the astrocytes arise?
Nutrient and gas exchange
DES
Neuroectoderm
Mullerian inhibitory factor from Sertoli cells; increased androgen from Leydig cells
42. What type of blood do umbilical veins carry? From where to where?
Oxygenated; placenta to fetus (IVC)
Ectoderm - mesoderm - endoderm; epiblast - primitive streak - hypoblast; week 3
Surface ectoderm
Temporary cervical sinus
43. What surrounds the umbilical cord?
Amniotic epithelium
Tetracyclines
Most pharyngeal constrictors - Cricothyroid - levator veli palatini; CN X (superior laryngeal branch - swallowing)
Annular pancrease
44. What day is the amnion formed?
Pharynx to duodenum; duodenum to transverse colon; distal transverse colon to rectum
can make cells
From teh lung;blood from IVC in RA to LA; fossa ovalis
8
45. When does the neural tube form and From what does it form?
Prosencephalon - mesencephalon - rhombencephalon
Cerebellar tonsillar herniation through foramen magnum
Neural plate; closes by week 4
Hypertrophy of muscularis externis of pylorus; surgical incision
46. What components do the neural crest cells of the branchial arches give rise to?
Bones - cartilage - and nerves
Ovarian ligament and round ligament of uterus; anchors testes within scrotum
Muscular ventricular septum; no
Wolffian; mullerian
47. What is used to keep the PDA open?
Prostaglandins
Bilateral loss of pain and temperature sensation in upper extremities with preservation of touch sensation
Temporary cervical sinus
A vitelline fistula - failure of vitelline duct to close
48. From where is the allantois formed? During what week?
External auditory meatus
3rd and 4th arches
Yolk sac; 3rd week
4th arch; 6th arch
49. What teratogen can cause IUGR and ADHD in a fetus? what else can this teratogen cause?
Neuroectoderm
arnold chiari associated with thoraclumbar myelomeningocele
Prostaglandins
Nicotine; preterm labor
50. From What embryonic layer is aorticopulmonary septum from ?
Female; paramesonephric; mesonephric
Incomplete; yes
Mesoderm
Neural crest cells