|
UMBILICAL CORD
VESSELS |
UMBILICAL ARTERIES |
- Two arteries arise from the aorta in the embryo, but after differentiation and growth they become branches of the internal iliac arteries in the fetus.
- Have 4 muscle layers (inner circular layer, longitudinal layer and two helical layers that function independently to coil the umbilical arteries).
- They course lateral to the urinary bladder toward the umbilical cord.
|
|
|
|
|
|
- Diameter = 2.4 mm (range = 1.1 - 2.8 mm). The diameter reaches a plateau at 32-34 weeks gestation.
Normal three vessel cord |
|
|
Two vessel cord |
|
|
Two and three vessel cord in the same fetus |
|
|
UMBILICAL VEIN |
- Normal
anatomy - one vein
- The right umbilical vein regresses by 6 weeks.
- The left umbilical vein enters the falciform ligament and joins the left portal vein.
- Diameter = 6.5 mm at 20 weeks and 10 mm at 30 weeks.
- Normal
umbilical vein waveform
|
Abdominal wall insertion of the cord |
Intrahepatic portion of the
umbilical vein
|
|
|
|
|
|
|
