Umbilical vein: Difference between revisions
No edit summary |
No edit summary |
||
Line 18: | Line 18: | ||
The '''umbilical vein''' is a [[vein]] present during fetal development that carries [[oxygenated blood]] from the [[placenta]] to the growing [[fetus]]. |
The '''umbilical vein''' is a [[vein]] present during fetal development that carries [[oxygenated blood]] from the [[placenta]] to the growing [[fetus]]. |
||
The blood pressure inside the umbilical vein is approximately |
The blood pressure inside the umbilical vein is approximately 17.6 mmHg.<ref>[http://www.embryology.ch/anglais/fplacenta/circulplac01.html Fetal and maternal blood circulation systems] From Online course in embryology for medicine students. Universities of Fribourg, Lausanne and Bern (Switzerland). Retrieved on 6 April, 2009</ref> |
||
==Closure== |
==Closure== |
Revision as of 15:43, 23 September 2012
Umbilical vein | |
---|---|
Details | |
Artery | umbilical artery |
Identifiers | |
Latin | vena umbilicalis |
MeSH | D014471 |
TA98 | A12.3.12.010 |
TA2 | 5103 |
FMA | 70317 |
Anatomical terminology |
The umbilical vein is a vein present during fetal development that carries oxygenated blood from the placenta to the growing fetus.
The blood pressure inside the umbilical vein is approximately 17.6 mmHg.[1]
Closure
Within a week of birth, the infant's umbilical vein is completely obliterated and is replaced by a fibrous cord called the round ligament of the liver (also called ligamentum teres hepatis). It extends from the umbilicus to the transverse fissure, where it joins with the falciform ligament of the liver to separate the left and right lobes of the liver.
Closure of the umbilical vein usually occurs after the umbilical arteries have closed. This prolongs the communication between the placenta and fetal heart, allowing for a sort of autotransfusion of remaining blood from the placenta to the fetus.
Recanalization
Under extreme pressure, the round ligament may reopen to allow the passage of blood. Such recanalization may be evident in patients with cirrhosis and portal hypertension. Patients with cirrhosis experience rapid growth of scar tissue in and around the liver, often functionally obstructing nearby vessels. Vessel occlusion increases vascular resistance and therefore leads to hypertension. In portal hypertension, the vessels surrounding the liver are subjected to abnormally high blood pressure—so high, in fact, that the force of the blood pressing against the round ligament is sufficient to recanalize the structure.
Catheterization
A newborn baby has a patent umbilical vein for at least a week after birth. This umbilical vein may be catheterised for ready intravenous access. It may be used as a site for regular transfusion in cases of erythroblastosis or hemolytic disease.
Additional images
-
Model of human embryo 1.3 mm. long.
-
Scheme of placental circulation.
-
Diagram of the vascular channels in a human embryo of the second week.
-
Human embryo with heart and anterior body-wall removed to show the sinus venosus and its tributaries.
-
Schematic figure of the bursa omentalis, etc. Human embryo of eight weeks.
-
Liver with the septum transversum. Human embryo 3 mm. long.
-
Tail end of human embryo twenty-five to twenty-nine days old.
-
Umbilical vein
References
- ^ Fetal and maternal blood circulation systems From Online course in embryology for medicine students. Universities of Fribourg, Lausanne and Bern (Switzerland). Retrieved on 6 April, 2009
- Template:GraySubject - "Peculiarities in the vascular system of the fetus"