questions 3

Umbilical Cord & Remnants

Topic updated on 08/06/17 8:41am

Normal Anatomy
  • Umbilical arteries
    • right and left umbilical arteries branching from internal iliac arteries return deoxygenated blood from the fetus
      • single umbilical artery is associated with increased likelihood of congenital abnormalities
  • Umbilical vein
    • single umbilical vein returns oxygenated blood from placenta to fetus
  • Allantois 
    • forms the umbilical arteries and vein
  • Urachal duct 
    • a duct extending from yolk sac to apex of the bladder
    • yolk sac forms allantois which becomes urachus
      • during development, the lumen of the uraches closes
      • adult remnant is median umbilical ligament
    • if urachus fails to close
      • patent urachus
        • urine leaks from umbilicus
      • vesicourachal diverticulum
        • bladder protrudes from umbilicus
  • Vitelline duct (omphalomesenteric duct)
    • connects yolk sac to midgut, closes during week 7
    • if vitelline duct lumen fails to close then
      • vitelline fistula
        • meconium discharge from umbilicus
      • Meckel's diverticulum (see "Meckel's Diverticulitis") 
        • failure of lumen to close on side opening to ileum 
        • can have ectopic gastric mucosa leading to melena and RLQ pain



Qbank (2 Questions)

(M1.EB.37) A 26-year-old G1P0 mother is in the delivery room in labor. Her unborn fetus is known to have a patent urachus. Which of the following abnormalities would you expect to observe in the infant? Topic Review Topic

1. Myelomeningocele
2. Gastroschisis
3. Omphalocele
4. Meconium discharge from umbilicus
5. Urine discharge from umbilicus

(M1.EB.62) A child is in the nursery one day after birth. A nurse notices a urine-like discharge being expressed through the umbilical stump. What two structures in the embryo are connected by the structure that failed to obliterate during the embryologic development of this child? Topic Review Topic

1. Pulmonary artery - aorta
2. Bladder - yolk sac
3. Bladder - small bowel
4. Liver - umbilical vein
5. Kidney - large bowel

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