Lymphatics of the Abdomen Anatomy
The lymphatic vessels and nodes of the abdomen drain the abdominal
and pelvic organs as well as the pelvic walls and the lower part of the abdominal wall. (The
upper part of the abdominal wall is drained by the internal thoracic and
axillary nodes; p. 145.) In addition, the abdominal lymphatics receive lymph
from the lower limb, the gonads and the perineum.
Some lymph nodes are situated adjacent to the organs they drain
and include those of the liver and spleen and in the hila of the kidneys. The
lymphatic vessels draining most of the abdominal organs accompany blood vessels
and pass to nodes grouped around the aorta. Often, lymph passes through
intermediate nodes situated along the courses of the
arteries. Most of the lymph from the abdominal walls and viscera eventually
drains into the thoracic duct.
Because of their deep position, most intra-abdominal lymph nodes
are not palpable in the living subject, even when enlarged.
The external iliac nodes (Fig. 4.93) receive lymph from the lower
limb and perineum via the deep inguinal nodes. In addition, the iliac nodes
drain the deeper layers of the abdominal wall below the level of the umbilicus
via lymphatic vessels accompanying the inferior epigastric vessels. Lymph from
the superficial tissues of the lower abdominal wall reaches the external iliac
nodes, having passed first to superficial and then to deep inguinal nodes.
The internal iliac nodes drain the
pelvic walls and floor and some of the pelvic organs, including the bladder,
lower part of the rectum, prostate and uterus. However, lymph from most of the
rectum, sigmoid colon and ovaries drains to the aortic nodes. From the external
and internal iliac nodes lymph passes to nodes alongside the common iliac
artery (Fig. 4.93) and subsequently to the aortic nodes.
Aortic nodes
The major abdominal lymphatic vessels and their associated nodes
are arranged alongside the aorta (Fig. 4.94). The nodes on each side of the
aorta receive lymph from the common iliac nodes, posterior abdominal wall,
gonads, kidneys and suprarenal glands, while nodes lying immediately anterior
to the aorta drain the digestive organs.
Nodes around the origin of the inferior mesenteric artery drain
lymph from most of the rectum and the sigmoid and descending parts of the
colon. Nodes lying adjacent to the origins of the superior mesenteric and
coeliac arteries drain the spleen, pancreas, liver, stomach, small intestine
and the large intestine as far as the splenic flexure.
Cisterna chyli
Efferent lymphatics from the aortic nodes drain into the cisterna
chyli (Fig. 4.95).
This fusiform sac lies at the level of the upper two lumbar vertebrae, adjacent
to the right crus of the diaphragm. It lies behind the right border of the
aorta and opens superiorly into the thoracic duct. The duct ascends through the
aortic opening of the diaphragm and continues through the thorax to drain into
the great veins in the root of the neck (p. 62).
Get more articles about science, anatomy, physiology, abdomen here
