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 What embryonic layer is the eustachian tube from?
Ebsteins anomaly; tricuspid atresia
DiGeorge
Turners; inferior
Mesoderm
2. what junction is the last to canalize? what implications does this have down the line?
Uretopelvis; most common site for obstruction (hydronephrosis) in fetus
4th pouch
Mullerian inhibitory factor from Sertoli cells; increased androgen from Leydig cells
Bone/cartilage and nerves
3. What separated myometrium of the uterus from the blastocyst?
Mesoderm
From endocardial cushions (ventral and dorsal meet each other)
Decidual basalis
Sperm plus egg
4. What does the ureteric bud interact with and What does it induce it to become?
Neuroectoderm
Metanephric mesenchyme; differentiation and formation of glomerulus and renal tubules to distal convoluted tubule
From teh lung;blood from IVC in RA to LA; fossa ovalis
Prosencephalon
5. From where does pons form from? what else forms from there?
From endocardial cushions (ventral and dorsal meet each other)
Metencephalon; cerebellum
1st cleft/groove (Ectoderm)
Partial closure of vitelline duct so that the patent portion is attached to ileum; ectopic gastric mucosa; melena and periumbilical pain
6. What type of - amnios does bilateral agenesis form? What three symptoms does this cause?
Surface ectoderm
Endoderm
Oligohydramnios
No organ in each; agenesis no primordial tissue
7. Where is the mothers blood located in the placenta?
Week 4
Medial palatine processes
Lacunae in between the chorionic villi
Increase in oxygen concentration which decreases prostaglandin concentration
8. what structures are the derivatives of the neural crest cells in branchial arches?
Pharynx to duodenum; duodenum to transverse colon; distal transverse colon to rectum
Wolffian; mullerian
blood entering the RA
Bone/cartilage and nerves
9. What components do the mesoderm of the branchial arches give rise to?
Ebsteins anomaly; tricuspid atresia
Muscles and arteries
Nicotine; preterm labor
Aortic arch and prox part of subclavian
10. Gastroschisis is extrusion of abdominal contents out of abdominal folds ___________ by peritoneum
not covered
From teh lung;blood from IVC in RA to LA; fossa ovalis
Valproate acid
Decreased separation of hemispheres across midline; cyclopia
11. What embryological structure gives rise to the trabeculated part of the left and right atrium?
Amniotic cavity and yolk sac
Primitive atrium
Pharynx to duodenum; duodenum to transverse colon; distal transverse colon to rectum
Right common cardinal vein and right anterior cardinal vein
12. From What embryonic layer is the vagina from? testes? ovaries?
VACTERL- vertebral defect - anal atresia - cardiac defects - tracheo - esophageal fistula - renal defects - limb defects
Excessive resorption of septum primum or secondum (or both)
Mesoderm
Decreases
13. What is holoprosencephaly? what eye disorder does it result in?
Neural crest cells
Surface ectoderm
3rd pouch
Decreased separation of hemispheres across midline; cyclopia
14. The spleen is ____________ in origin and supplied by a foregut artery
Right horn of the SV
3rd pouch
mesodermal
Ventral shaft of penis (penile urethra); labia minora
15. During what periods do the damages that cerebral palsy causes occur?
Mesoderm; nucleous pulposos
Decidual basalis
Prenatal and perinatal
Mesoderm
16. What does the midgut form? hindgut?
Ventral and dorsal parts fail to fuse at 8th week; 2 pancreatic ducts!- more prone to pancreatitis
Gastric outlet obstruction (bilious vomiting - feeding intolerance - abdominal distention)
Neural crest cells
Duodenum to transverse colon; distal transverse colon to rectum
17. what invaginates to form the primitive streak?
Bulbos Cordis; right ventricle entirely
Aberrant development of 3rd and 4th pouches; t cell def (thymic aplasia) - hypocalcemia (failure of parathyroid development) - CF and CV defects
Nutrient and gas for exchange; endometrium
Epiblast
18. In what chromosomal disorder is horseshoe kidney commonly seen? what poles of the kidneys fuse?
Synctiotrophoblast; outer; no
Amniotic epithelium
Week 4; week 3
Turners; inferior
19. How do adults with annular pancreas present? and At What age?
Week 4
Partial closure of vitelline duct so that the patent portion is attached to ileum; ectopic gastric mucosa; melena and periumbilical pain
20-50yrs - Abdominal pain - Postprandial fullness - Nausea - Peptic ulcers - Pancreatitis - Rarely - biliary obstruction
hypospadias
20. Where is the decidua basalis derived from?
Endometrium
Mesonephros; male genital system
Myelencephalon
Bilateral loss of pain and temperature sensation in upper extremities with preservation of touch sensation
21. What causes persistent Truncus Arteriosus? What does it result in?
LH
Partial AP septum development; one large vessel leaves the heart - Right to left shunt
3rd pouch
Nutrient and gas exchange
22. What surrounds the umbilical cord?
4th arch; 6th arch
Bulbourethral glands (of Cowper) and Prostate gland; greater vestibular glands (of Bartholin) and Urethral and paraurethral glands (of Skene)
Amniotic epithelium
Maxillary
23. Which branchial apparatus derivative makes the tympanic membrane of the ear?
Membrane - all 3 from 1st appartus
Glans penis and corpus cavernosum and spongiosum; glans clitoris and vestibular bulbs
Endoderm
Week 8
24. what chemo drugs can cause neural tube defects in the fetus?
Cleft lip/palate
Fluid filled syrinx causes expansion and degeneration of cord tracts
Surface ectoderm
Folate antagonists
25. What part of the gut rotates around the SMA? and At what point?
When the AP septum meets and fuses with the muscular ventricular septum to form membranous intraventricular septum - closing interventricular foramen
Midgut; 10th week
Week 8
Increased AFP and acetycholinesterase (not ACh!) in CSF
26. What do the groove/clefts of the branchial apparatus correlate to?
Germinal matrix hemorrhage
Ectoderm
When the AP septum meets and fuses with the muscular ventricular septum to form membranous intraventricular septum - closing interventricular foramen
IX; X
27. From What embryonic layer does the brain arise?
Polyhydramnios - Down syndrome - Esophageal/duodenal atresia - Imperforate anus - Meckel diverticulum
Week 8
Neuroectoderm
is no longer intact
28. From What embryonic layer do the ependymal cells arise?
Neuroectoderm
VACTERL; OCPs and maternal diabetes
Endoderm
monoamniotic
29. What does the first branchial pouch create?
Oligohydramnios
Aortic arch (from left side); right subclavian (on the right)
Endoderm lined structures of ear: middle ear cavity - eustacian tube - mastoid air cells
Fallopian tube - uterus - upper 1/3 of vagina
30. From which myotomes are muscles of the tongue derived from?
All or none
They are the edge of neural plate folding; all over the body
Prosencephalon
Occiptal
31. What do membranous interventricular septal defect cause? What does this lead to?
Arnold Chiari and Dandy Walker; Arnold Chiari; Dandy Walker; Arnold Chiari
4th/5th branchial pouches
Initial left to right shunting - then switches
Fetal kidney; fetal swallows - absorbs - and then removed from placental blood
32. Where is the apical ectodermal ridge?
Surface ectoderm
Membrane - all 3 from 1st appartus
Thickened ectoderm at end of each developing limb
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
33. What type of blood do umbilical arteries carry? From where to where?
Week 10-12; end of 1st trimester
Deoxygenated blood; fetal internal iliac arteries to placenta
lumbosacral
Diencephalon
34. When does the neural tube form and From what does it form?
Neural plate; closes by week 4
Synctiotrophoblast; outer; no
8
Dorsal and ventral buds
35. From What embryonic layer does the gut tube derivatives arise (lungs liver - pancreas - parathryroid - thyroid follicular cells - thymus)?
Endoderm
3rd pouch
3 -4 -6
Neural crest cells
36. what muscles are derived from branchial arch 2?
Increase in oxygen concentration which decreases prostaglandin concentration
Tetracyclines
Muscles of facial expression - stapedius - stylohyoid - posterior belly of the digastric
Cerebellar tonsillar herniation through foramen magnum
37. From what region of the brain does the lateral ventricles and the 3rd ventricle form?
Vascular accident intra uterine; apple peel atresia
Prosencephalon
Pharynx to duodenum; duodenum to transverse colon; distal transverse colon to rectum
Nicotine; preterm labor
38. From where is the pancreas derived? the spleen?
After; extrinsic
Foregut; dorsal mesentery (mesodermal)
Right common cardinal vein and right anterior cardinal vein
Neural crest cells
39. Which branchial apparatus develops into the inferior parathyroids?
Failure of bony spinal canal to fuse; no; lower vertebral levels
3rd pouch
lumbosacral
Membrane - all 3 from 1st appartus
40. From What embryonic layer does the thyroid follicular cells arise?
Neuroectoderm
1st cleft/groove (Ectoderm)
Endoderm
Day 6; maintains corpus luteum; 1st trimester
41. During what months is the fetus most susceptible to teratogens? What trimester?
Embryonic period; 1st trimester
Neural crest cells
3rd and 4th arches
Decreases
42. What is the memranous interventricular formaen made from?
From the the lung; blood from SVC that went into RV gets shunted from pulm artery to aorta; ligamentum arteriosum
Mesencephalon
During; instrinsic
When the AP septum meets and fuses with the muscular ventricular septum to form membranous intraventricular septum - closing interventricular foramen
43. What does the ductus venosus shunt blood away from? What is its remnant?
Post. sup wall; luteal phase
Polyhydramnios - Down syndrome - Esophageal/duodenal atresia - Imperforate anus - Meckel diverticulum
IX; X
Hepatic circulation; ligamentum venosum
44. From What embryonic layer does the skin dermis arise?
1st arch neural crest fails to migrate --> mandibular hypoplasia - facial abnormalities (cleft palate - decreased slanting of palpebral fissures)
SRY gene on Y chromosomes; sertoli and leydi; MIF and androgens; suppression of paramesonephric ducts and dev. of mesonephric (all respectively)
Mesoderm
Failure to spiral (aorta coming out of RV and PA coming out of left ventricle)- two completely separate systems
45. From What embryonic layer does the inner arise?
Mullerian inhibitory factor from Sertoli cells; increased androgen from Leydig cells
...
DiGeorge
Prosencephalon - mesencephalon - rhombencephalon
46. What causes meconium discharge from the umbilicus?
Mesoderm
A vitelline fistula - failure of vitelline duct to close
3 -4 -6
Week 10-12; end of 1st trimester
47. When does the blastocyst split into two disks? What is this disk called? What are the two germ layers called?
Partial closure of vitelline duct so that the patent portion is attached to ileum; ectopic gastric mucosa; melena and periumbilical pain
Week 2; bilaminar disk; epiblast and hypoblast
Neuroectoderm
20-50yrs - Abdominal pain - Postprandial fullness - Nausea - Peptic ulcers - Pancreatitis - Rarely - biliary obstruction
48. From What embryonic layer does the parathyroid arise ?
The caudal end mesonephros; the ureter - pelvis - calyces - collecting ducts
Left horn of the sinus venosus
Endometrium
Endoderm
49. What teratogen can cause an absence of digits amongst other things in the fetus? give an example.
Bone/cartilage and nerves
Dorsal and ventral buds
Deformation
Alkylating agents
50. From What embryonic layer are the pia and arachnoid from?
Neural crest cells
is no longer intact
Skewed development of AP septum
SRY gene on Y chromosomes; sertoli and leydi; MIF and androgens; suppression of paramesonephric ducts and dev. of mesonephric (all respectively)