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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. When does hcG get secreted? What does it do?up until when ?
IMA
Deformation
Pulm art (prox) and ductus arteriosus
Day 6; maintains corpus luteum; 1st trimester
2. What happens in pancreas divisum? what results?
Endoderm - floor of primitive pharynx
Neural crest cells
Arnold Chiari and Dandy Walker; Arnold Chiari; Dandy Walker; Arnold Chiari
Ventral and dorsal parts fail to fuse at 8th week; 2 pancreatic ducts!- more prone to pancreatitis
3. As a horseshoe kidney ascends during kidney development - What do they get trapped under?
Truncus arteriosus; pulmonary trunk
IMA
Neural crest migration - they then cause spiral
mesodermal
4. What does DHT turn the genital tubercle into? estrogen?
Glans penis and corpus cavernosum and spongiosum; glans clitoris and vestibular bulbs
Deoxygenated blood; fetal internal iliac arteries to placenta
monoamniotic
Mesoderm
5. When does the neural tube form and From what does it form?
Neural plate; closes by week 4
Cytotrophoblast
Mesoderm
Deformation
6. What do the arches of the branchial apparatus correlate to?
LH
Mesdoerm
Fluid filled syrinx causes expansion and degeneration of cord tracts
Neural crest development; MEN 2A (pheo - PTH tumor - parafollicular cell tumor)
7. From what arches are the neural crest cells that form the aorticpulmonary septum derived?
Mesoderm
3 -4 -6
Mesdoerm
Endometrium
8. From What embryonic layer do the ependymal cells arise?
can make cells
OCPS and maternal diabetes
Dorsal ventral axis
Neuroectoderm
9. Where is the mothers blood located in the placenta?
Failure of the urachus to obliterate
Lacunae in between the chorionic villi
When the AP septum meets and fuses with the muscular ventricular septum to form membranous intraventricular septum - closing interventricular foramen
Muscles of Mastication: Temporalis - masseter - Lateral and Medila pterygoids - Mylohyoid - anterior belly of the digastric - tensor tympani - tensor veli palatini; ant 2/3 of tongue
10. What embryological structures give rise to the SVC?
Right common cardinal vein and right anterior cardinal vein
Endoderm lined structures of ear: middle ear cavity - eustacian tube - mastoid air cells
Foregut; dorsal mesentery (mesodermal)
Annular pancrease
11. What separates the ant 1/3 and post 2/3 of tongue?
Foramen cecum and terminal sulus
Ring of pancreatic tissue can cause duodenal narrowing; ventral pancreatic bud abnormally encircles 2nd part of duodenum
Common carotid and internal carotid
Mesoderm; 3 week
12. which tracts are damaged first in syringomelia? What tract is preserved?
...
Spinothalamic first
Renal artery stenosis;
Mesoderm
13. Where is the decidua basalis derived from?
Bulbos Cordis; right ventricle entirely
Mental retardation - holoprosencephaly - facial features - fistulas
Cytotrophoblast
Endometrium
14. Where is the FGF gene produced? What is it responsible for - How does it do this?
Respiratory distress syndrome
No more umbilical circulation emptying into RA
Bone/cartilage and nerves
Apical ectodermal ridge; limb lengthening; stimulates mitosis of underlying mesoderm
15. From What embryonic layer is the vagina from? testes? ovaries?
DES
Muscular ventricular septum; no
Mesoderm
Amniotic epithelium
16. Pyloric stenosis is characterized by _____________ of muscularis externis in the sphincter
Tongue
Thyroid - cricoid - arytenoids - corniculate cuneiform
hypertrophy
Decreased pulmonary resistance in the pulmonary vasculature
17. From what region of the brain does the fourth ventricle form?
Arches 3 and 4
Neural crest cells
Rhombencephalon
Incomplete; yes
18. What is the leading cause of birth defects in the US? what else is this perpetrator the leading cause of?
3rd pouch
Physiologic incomplete muscular ventricular septum
Fetal alcohol syndrome; mental retardation
Ectoderm
19. Where does the blastocyst implant in the uterus? During what phase of the menstrual cycle?
Prostaglandins
Bulbourethral glands (of Cowper) and Prostate gland; greater vestibular glands (of Bartholin) and Urethral and paraurethral glands (of Skene)
Post. sup wall; luteal phase
Urogenital sinus; wolffian duct; mullerian duct; urogenital sinus; wolffian duct; wolffian duct; mullerian; mullerian
20. what bone/cartilage and nerves are derived from branchial arch 1?
Sonic Hedgehog
Most pharyngeal constrictors - Cricothyroid - levator veli palatini; CN X (superior laryngeal branch - swallowing)
Meckels cartilage: mandible - malleus - INCUS - sphenoMandibular ligament; CN V2 and V3
Prostaglandins
21. How do adults with annular pancreas present? and At What age?
Primitive atrium
20-50yrs - Abdominal pain - Postprandial fullness - Nausea - Peptic ulcers - Pancreatitis - Rarely - biliary obstruction
Post. sup wall; luteal phase
Surface ectoderm
22. From what region of the brain does the lateral ventricles and the 3rd ventricle form?
Obliterated; forms tunica vaginalis
The caudal end mesonephros; the ureter - pelvis - calyces - collecting ducts
Polyhydramnios - Down syndrome - Esophageal/duodenal atresia - Imperforate anus - Meckel diverticulum
Prosencephalon
23. What type of blood do umbilical arteries carry? From where to where?
IMA
The caudal end mesonephros; the ureter - pelvis - calyces - collecting ducts
Deoxygenated blood; fetal internal iliac arteries to placenta
Palpable olive mass in epigastric region; nonbilious projectile vomitting @around 2 weeks
24. what bone/cartilage are derived from branchial arch 4-6?
Umbilical - midgut herniates through umbilical ring; SMA
Persistence of 3rd cleft (groove) and pouch causes fistula between tonsillar area and cleft in lateral neck
Thyroid - cricoid - arytenoids - corniculate cuneiform
Mesencephalon
25. What embryological structure gives rise to the trabeculated part of the left and right atrium?
Branchial arch 2
Primitive atrium
Female; paramesonephric; mesonephric
Congenital and chromosomal abnormalities
26. From what region of the brain does the aqueduct form?
LH
Alkylating agents
Rhombencephalon
Neuroectoderm
27. What teratogen can cause IUGR and ADHD in a fetus? what else can this teratogen cause?
Primitive atrium
Nicotine; preterm labor
Pataus; fetal alcohol syndrome
Mullerian inhibitory factor from Sertoli cells; increased androgen from Leydig cells
28. What does the ductus arteriosus shunt blood away from - to where? What is its remnant?
From the the lung; blood from SVC that went into RV gets shunted from pulm artery to aorta; ligamentum arteriosum
Occiptal
Week 8
Neural crest cells
29. What does the first cleft/groove of the branchial apparatus develop into?
External auditory meatus
Maxillary
Neural crest migration - they then cause spiral
Oligohydramnios
30. From What embryonic layer is the kidney and the adrenal cortex from?
Ectoderm - mesoderm - endoderm; epiblast - primitive streak - hypoblast; week 3
6th aortic arch
Aminoglycosides
Mesoderm
31. What does DHT turn the urogenital sinus into? estrogen?
Bulbourethral glands (of Cowper) and Prostate gland; greater vestibular glands (of Bartholin) and Urethral and paraurethral glands (of Skene)
Rhombencephalon
1st arch neural crest fails to migrate --> mandibular hypoplasia - facial abnormalities (cleft palate - decreased slanting of palpebral fissures)
LH
32. What is Treacher Collins syndrome? What is the result?
monoamniotic
Greater horn of hyoid; CN IX (styloPharyngeus)
1st arch neural crest fails to migrate --> mandibular hypoplasia - facial abnormalities (cleft palate - decreased slanting of palpebral fissures)
Nutrient and gas exchange
33. What do the 2nd through 4th clefts of the branchial apparatus correlate to?
Muscular ventricular septum; no
Mesoderm
Temporary cervical sinus
3rd pouch
34. From What embryonic layer does the parathyroid arise ?
Maternally derived; meconium
Caused by compression on trocheal nerve - causes vertical gaze paralysis (associated with arnold chiari)
3rd pouch
Endoderm
35. From What embryonic layer does the adenohypophysis arise?
IMA
Surface ectoderm
Cleft lip/palate
Congenital and chromosomal abnormalities
36. What are two common findings in pyloric stenosis?
Neural crest cells
Palpable olive mass in epigastric region; nonbilious projectile vomitting @around 2 weeks
Endoderm - floor of primitive pharynx
Mesoderm
37. From where did a branchial cleft cyst arise if it found?
Prostaglandins
3rd and 4th arches
Reicherts cartilage: Stapes - Styloid process - Lesser horn of hyloid - Stylohyoid ligament and CN VII
Found in lateral neck; from no obliteration of 2-4th clefts
38. How many umbilical arteries are there? How many umbilical veins?
2; 1
Incomplete fusion of paramesonephric ducts; UT abnormalities and infertility
Muscles and arteries
Mesoderm; epiblast
39. Which branchial derivative creates the middle ear cavity - eustachian tube and mastoid air cells?
Dorsal and ventral buds
First branchial pouch
All 3
Left horn of the sinus venosus
40. Which part of the branchial apparatus makes up membranes?
All 3
Branchial arch 2
Primitive atrium
Physiologic incomplete muscular ventricular septum
41. WithIn what week does gastrulation occur? What is gastrulation?
Week 3; primitive streak formation from the epiblast makes the three layers
Glans penis and corpus cavernosum and spongiosum; glans clitoris and vestibular bulbs
Rhombencephalon
3
42. During what week does the heart begin to beat?
Mesoderm
Week 4
Mesdoerm
Mental retardation - holoprosencephaly - facial features - fistulas
43. What teratogen can cause inhibition of intestinal folate absorption and thus neural tube defects?
Prevent recurrent UTIs
Synctiotrophoblast
Valproate acid
Initial left to right shunting - then switches
44. What gene is produced in the zone of polarizing activity?
V3; VII
Sonic Hedgehog
Pataus; fetal alcohol syndrome
Ectoderm
45. Which arches form the posterior 1/3 of the tongue?
Hypertrophy of muscularis externis of pylorus; surgical incision
Synctiotrophoblast; outer; no
IMA
Arches 3 and 4
46. In what chromosomal disorder is horseshoe kidney commonly seen? what poles of the kidneys fuse?
hypospadias
Endoderm
Turners; inferior
Endoderm - floor of primitive pharynx
47. What are the three results of having pathology in the aorticopulmonary septum?
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)
Yolk sac; 3rd week
Nutrient and gas exchange
Deformation
48. Which cranial nerve innervates the motor function of the tongue?
Cytotrophoblast and synctiotrophoblast
Dorsal; faulty positioning of genital tubercle
XII
Fluid filled syrinx causes expansion and degeneration of cord tracts
49. In both meningocele and myelomeningocele the dura...
is no longer intact
mesoderm
All 3
Prostaglandins
50. With the first breath the infant take - pulmonary vasculature resistance _______ which causes an increase in left atrial pressure
mesoderm
Decreases
Endoderm - floor of primitive pharynx
3rd and 4th arches