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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 secretes hCG?
Synctiotrophoblast
Surface ectoderm
Rostral fold closure ; lateral fold closure; lateral fold closure; caudal fold closure
Week 4; week 3
2. Where is the mothers blood located in the placenta?
Mesoderm; 3 week
Lacunae in between the chorionic villi
Mesoderm
Muscles of facial expression - stapedius - stylohyoid - posterior belly of the digastric
3. To what germ layer does the branchial pouches correlate to?
Endoderm
Pulm art (prox) and ductus arteriosus
No organ in each; agenesis no primordial tissue
Aortic arch and prox part of subclavian
4. From what aortic arch does the common carotid artery arise? what else arises from this arch?
Apical ectodermal ridge
First branchial pouch
3rd; proximal part of the internal carotid artery
Surface ectoderm
5. During what months is the fetus most susceptible to teratogens? What trimester?
Embryonic period; 1st trimester
Ectoderm; endoderm
Week 4
Dorsal and ventral buds
6. What can vit A in excess cause in the fetus?
Physiologic incomplete muscular ventricular septum
Lots - cleft palate/lip
Surface ectoderm
DES
7. Where is the most common ectopic thyroid tissue?
Tongue
Thyroglossal duct cysts will move with swallowing while persistent cervical sinuses in lateral neck wont
Neural crest development; MEN 2A (pheo - PTH tumor - parafollicular cell tumor)
1st arch neural crest fails to migrate --> mandibular hypoplasia - facial abnormalities (cleft palate - decreased slanting of palpebral fissures)
8. What do the arches of the branchial apparatus correlate to?
Post. sup wall; luteal phase
Neural crest cells
Mesdoerm
Ionizing
9. What is the prochordal plate?
Where the epiblast and hypoblast fuse
Dorsal; sensory
Obliterated; forms tunica vaginalis
Folate antagonists
10. What are the two walls of the prosencephalon and What do they become?
Valproate acid
Thalidomide; nausea
Cerebral hemisphere - thalami
primary palate
11. Which branchial derivative creates the middle ear cavity - eustachian tube and mastoid air cells?
pyloric stenosis
First branchial pouch
Truncus arteriosus; pulmonary trunk
Neuroectoderm
12. what separates the atria from the ventricles?
Epiblast
Dorsal and ventral buds
Metencephalon; cerebellum
Endocardial cushions
13. What is Treacher Collins syndrome? What is the result?
Neural crest cells
Partial AP septum development; one large vessel leaves the heart - Right to left shunt
XII
1st arch neural crest fails to migrate --> mandibular hypoplasia - facial abnormalities (cleft palate - decreased slanting of palpebral fissures)
14. What surrounds the umbilical cord?
Amniotic epithelium
ACE inhibitors - HCTZ
Common carotid and internal carotid
3rd; proximal part of the internal carotid artery
15. What is perinauds syndrome?
Germinal matrix hemorrhage
Most pharyngeal constrictors - Cricothyroid - levator veli palatini; CN X (superior laryngeal branch - swallowing)
A vitelline fistula - failure of vitelline duct to close
Caused by compression on trocheal nerve - causes vertical gaze paralysis (associated with arnold chiari)
16. What does the midgut form? hindgut?
Rhombencephalon
Duodenum to transverse colon; distal transverse colon to rectum
IX; X
External auditory meatus
17. What is the homeobox gene responsible in developing? (What axis)
2nd pouch
Cranio - caudal; segmental
Decreased separation of hemispheres across midline; cyclopia
Week 8
18. What day is the amnion formed?
Week 3-8
6th aortic arch
8
pyloric stenosis
19. From What embryonic layer does the oligodendrocytes arise?
Neuroectoderm
Surface ectoderm
Aortic arch (from left side); right subclavian (on the right)
Membrane - all 3 from 1st appartus
20. What do membranous interventricular septal defect cause? What does this lead to?
Mesoderm; 3 week
Week 3; primitive streak formation from the epiblast makes the three layers
Initial left to right shunting - then switches
Arnold Chiari and Dandy Walker; Arnold Chiari; Dandy Walker; Arnold Chiari
21. WithIn what week does gastrulation occur? What is gastrulation?
1st arch neural crest fails to migrate --> mandibular hypoplasia - facial abnormalities (cleft palate - decreased slanting of palpebral fissures)
1st cleft/groove (Ectoderm)
Week 3; primitive streak formation from the epiblast makes the three layers
Endoderm
22. What is the neural plate and From what does it form?
Bilateral loss of pain and temperature sensation in upper extremities with preservation of touch sensation
Endoderm - floor of primitive pharynx
Ectoderm
Surface ectoderm
23. From What embryonic layer does bone arise ?
Blastocyst; epiblast and hypoblast; synctiotrophoblast and cytotrophoblast
Mesoderm
Aminoglycosides
VSD
24. In anencephaly you see...
They are the edge of neural plate folding; all over the body
elevated AFP
Endoderm lined structures of ear: middle ear cavity - eustacian tube - mastoid air cells
Nutrient and gas exchange
25. From What embryonic layer is the vagina from? testes? ovaries?
Upper 1/3; urogenital sinus
3rd pouch
Fallopian tube - uterus - upper 1/3 of vagina
Mesoderm
26. From What embryonic layer does the brain arise?
Prenatal and perinatal
Neuroectoderm
Ectoderm
Ovarian ligament and round ligament of uterus; anchors testes within scrotum
27. _____________is common in 1st born males
T neuroectoderm
Polyhydramnios
Deoxygenated blood; fetal internal iliac arteries to placenta
pyloric stenosis
28. what invaginates to form the primitive streak?
Epiblast
Spinothalamic first
Ectoderm
Pharynx to duodenum; duodenum to transverse colon; distal transverse colon to rectum
29. What causes tetralogy of Fallot?
Nutrient and gas for exchange; endometrium
1st
Dorsal ventral axis
Skewed development of AP septum
30. From What embryonic layer does connective tissue and muscle arise?
Endoderm lined structures of ear: middle ear cavity - eustacian tube - mastoid air cells
Mesoderm
Umbilical artery - vein; and whartons jelly (mucus connective tissue) - urachus
Left horn of the sinus venosus
31. As a horseshoe kidney ascends during kidney development - What do they get trapped under?
Mid gut to yolk sac; omphalomesenteric duct; 7th week
IMA
Fallopian tube - uterus - upper 1/3 of vagina
Muscles of facial expression - stapedius - stylohyoid - posterior belly of the digastric
32. From what region does the midbrain form from?
Pataus; fetal alcohol syndrome
Mesoderm
Mesencephalon
Mesoderm
33. 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
Polyhydramnios - Down syndrome - Esophageal/duodenal atresia - Imperforate anus - Meckel diverticulum
Epiblast
Tunica vaginalis not fully fused
34. What axis does the basal plate form? what neural system does it become?
Valproate acid
Ventral ; motor
Endoderm
Ectoderm - mesoderm - endoderm; epiblast - primitive streak - hypoblast; week 3
35. What causes the transposition of the great vessels? What does it result in?
Dorsal; sensory
No more umbilical circulation emptying into RA
Female; paramesonephric; mesonephric
Failure to spiral (aorta coming out of RV and PA coming out of left ventricle)- two completely separate systems
36. What is the initial step to interventricular septum development? is it complete?
Muscular ventricular septum; no
All or none
IMA
Ventral and dorsal parts fail to fuse at 8th week; 2 pancreatic ducts!- more prone to pancreatitis
37. Where is Wnt 7 gene produced?
Polyhydramnios
Neural crest cells
Apical ectodermal ridge
Deoxygenated blood; fetal internal iliac arteries to placenta
38. What does DHT turn the urogenital sinus into? estrogen?
Rhombencephalon
Bulbourethral glands (of Cowper) and Prostate gland; greater vestibular glands (of Bartholin) and Urethral and paraurethral glands (of Skene)
Nutrient and gas exchange
1st cleft/groove (Ectoderm)
39. From What embryonic layer is the kidney and the adrenal cortex from?
When the AP septum meets and fuses with the muscular ventricular septum to form membranous intraventricular septum - closing interventricular foramen
Neural crest cells
Common carotid and internal carotid
Mesoderm
40. From what branchial derivative do the parafollicular cells arise?
4th/5th branchial pouches
Glans penis and corpus cavernosum and spongiosum; glans clitoris and vestibular bulbs
Mesoderm; epiblast
Decidual basalis
41. Where does the blastocyst implant in the uterus? During what phase of the menstrual cycle?
Failure of the urachus to obliterate; outpouching of the bladder
Mesencephalon
6th aortic arch
Post. sup wall; luteal phase
42. From What embryonic layer does the sensory organs of the ear arise?
28 week onward
Surface ectoderm
...
Bone/cartilage and nerves
43. What embryological structures give rise to the SVC?
All intrinsic muscles of larynx except cricothyroid; CN X (recurrent laryngeal nerve - speaking)
VACTERL; OCPs and maternal diabetes
Ventral bud
Right common cardinal vein and right anterior cardinal vein
44. What does the RET gene encode? what neoplasias is it associated with?
Neural crest development; MEN 2A (pheo - PTH tumor - parafollicular cell tumor)
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)
Surface ectoderm
Primitive atrium
45. Cleft palate is a failure of fusion of the lateral palatine processes - the nasal septum and or the ________?
Medial palatine processes
Mesoderm
can make cells
Prenatal and perinatal
46. From what region of the brain does the fourth ventricle form?
Mesdoerm
Week 4
Rhombencephalon
hypertrophy
47. which tracts are damaged first in syringomelia? What tract is preserved?
V3; VII
Spinothalamic first
Ectoderm - mesoderm - endoderm; epiblast - primitive streak - hypoblast; week 3
Week 4
48. Septum primum (patent foramen oval) caused by excessive resorption of...
Cleft lip/palate
4th/5th branchial pouches
Day 6; maintains corpus luteum; 1st trimester
septum primum and/or secundum
49. what bone/cartilage and nerves are derived from branchial arch 2?
Neural crest cells
Cerebellar tonsillar herniation through foramen magnum
Reicherts cartilage: Stapes - Styloid process - Lesser horn of hyloid - Stylohyoid ligament and CN VII
Urogenital sinus; wolffian duct; mullerian duct; urogenital sinus; wolffian duct; wolffian duct; mullerian; mullerian
50. What teratogens can cause renal damage in the fetus?
Yolk sac; 3rd week
ACE inhibitors - HCTZ
Nutrient and gas exchange
6-30