The lymph nodes of posterior abdominal wall are closely related to aorta and form two distinct chains: pre-aortic chain and para-aortic chain.
Pre-aortic chain of lymph nodes:
The preaortic lymph nodes form three distinct groups. These groups lie around the origins of celiac artery, superior mesenteric artery and inferior mesenteric artery. Because of this relation, these groups are respectively known as celia, superior mesenteric and inferior mesenteric lymph nodes.
These lymph nodes receive lymph from the gastrointestinal tract, extending from lower part of esophagus to halfway down the anal canal. They also receive lymph from spleen, pancreas, gall bladder and greater part of liver. The efferent lymph vessels of these nodes form the large intestinal trunk.
Para-aortic chain of lymph nodes:
The para-aortic chain consists of right and left lateral chains of lymph nodes. They drain lymph from kidneys, adrenal glands, deep lymph vessels of abdominal walls, common iliac nodes and from testis in males and ovaries, uterine tubes and fundus of uterus in females. The efferent lymph vessels from these nodes form the right and left lumbar trunks.