The anal canal can be conveniently divide into two parts. The upper 2/3 is endodermal in origin, while the lower is ectoderm, i.e. skin. Between the two is a mucocutaneous junction. Lymphatic vessels above the junction drains with the lower rectal vessels into the internal iliac nodes, either via the middle rectal route (accompanies middle rectal artery to internal iliac artery) or the inferior rectal route (accompanies the inferior rectal artery to the internal pudendal artery and from there to the internal iliac artery). The lower half of the anal canal is drained by the superficial inguinal nodes. These nodes then reach the external iliac nodes to the lateral aortic nodes and to the lumbar lymph trunk. The lumbar lymph trunks help to form the abdominal confluence of lymph ducts or the cisterna chyli. Cistern chyli drains into thoracic duct.


There is nothing in anatomy not found in this website