Abstract
Results of macroscopic observation on the fetal chorionic vasculature of 76 cases of human placentas are described in this paper. This has been done with the aid of corrosion anatomical preparations.
1. Umbilical veins concentrated most frequently in 3-branched form at the root (48.6±5.55 %) .
2. On the running-type of chorionic arteries and veins, I type (radiant type) was seen in 39.2±5.91 % (artery) and 38.2±5.57 % (vein), II type (antler type), III type (outspread fan type), and branched tree type succeeded in order.
3. As regards to the branching-type of blood vessels, radiant type was most frequently seen on the placentas of central of insertion of umbilical cord, and antler type and outspread fan type were relatively frequent on the lateral insertion.
4. The communication between two umbilical arteries was situated near the insertion of umbilical cord at the placentas. The communication was absent in 3.9±2.22 %.
5. As to the communication between two arteries, two types were seen : (1) the one with adhesive fusion between two arteries. Communication-branch was devided into 3 groups, and the fusion into 2 groups.
6. The type with double communication-branch (never has been described) was seen in 2 cases (3.5 ± 2.45 %), which had one communication-branch between two main arteries with the communication-branch between one main artery and the second branch of the other main artery.
7. Two umblical arteries had the communication for the most part near the insertion of umbilical cord and inside of placenta. Communications in the umbilical cord were rarely seen.
8. Communication-branch and adhesive fusion between two umbilical arteries mostly had the length under 1.0 cm.
9. As regards to the relation between first branch and communication-branch of umbilical artery trunk, the first branch started mostly after making the communication (82.2±4.51 %) .
