USMLE Embryology

  1. Layer secreting hCG
  2. maternal portion of placenta
    Decidua basalis
  3. Vitelline fisulta
    • Meconium discharge from umbilicus
    • Meckel's diverticulum
  4. Truncus arteriosus structures
    Ascending aorta and pulmonary trunk
  5. Bulbus cordis structures
    Right ventricle and smooth parts (outflow) of left and right ventricle
  6. Primative ventricle
    Portion of left ventricle
  7. Primitive atria
    Trabeculated left and right atrium
  8. Left horn of sinus venosus
    Coronary sinus
  9. Right horn of sinus venosus
    Smooth part of right atrium
  10. What gives rise to the SVC
    Right common cardinal vein and right anterior cardinal vein
  11. What chemical occurence causes ductus arteriosus closure
    • Increased oxygen leads to decrease in prostaglandins
    • That's why indomethicin closes PDA and prostaglandins keep it open
  12. 1st aortic arch
    maxillary artery
  13. 2nd aortic arch
    Stapedial artery and hyoid artery
  14. 3rd aortic arch
    Common carotid artery and proximal IC
  15. 4th aortic arch
    • L: aortic arch
    • R: proximal part of right subclavian artery
  16. 6th aortic arch
    pulmonary arteries and ductus arteriosis
  17. 1st branchial arch: cartilage, muscle, nerve
    • Mandible, Malleus, incus, spheno-Mandibular ligament
    • Mastication, Mylohyoid, tensors, anterior belly of digastric, ant tongue
    • CN V2 and V3
  18. 2nd branchial arch: cartilage, muscle, nerve
    • Stapes, Styloid process, Stylohyoid ligament, Reichert's cartilage
    • Facial muscles, Stapedius, Stylohyoid, post belly of digastric
    • CN VII
  19. 3rd branchial arch: cartilage, muscle, nerve
    • Greater horn of hyoid
    • Stylopharyngeus
    • CN IX (glossopharyngeal)
  20. Branchial arch 3 abnormality
    • congenital pharyngo-cutaneous fistula
    • cleft and pouch connected, cleft in lateral neck
  21. Branchial arch 4-6 cartilage
    Thyroid, cricoid, arytenoids, corniculate, cuneiform
  22. Branchial arch 4: muscles and nerve
    • pharyngeal constrictors, cricothyroid, levator veli palitine
    • CN X (swallowing)
  23. Branchial arch 6: muscle and nerve
    • All intrinsic larynx mm except cricothyroid
    • CN X (recurrent laryngeal for speaking)
  24. External auditory meatus comes from
    1st branchial cleft
  25. 1st branchial pouch
    middle ear cavity, eustachian tube, mastoid air cells
  26. 2nd branchial pouch
    Palatine tonsil lining
  27. 3rd branchial pouch
    thymus, inferior parathyroids
  28. 4th branchial pouch
    superior parathyroids
  29. Ureteric bud of metanephros gives rise to
    everything from the collecting duct to the ureter
  30. Metanephric mesenchyme gives rise to
    everything from the glom to the DCT
  31. Potter's syndrome
    • Bilateral renal agenesis (ureteric bud malformation) causing oligohydramnios
    • limb deformities, facial deformities, pulm hypoplasia
Card Set
USMLE Embryology
Embryology USMLE