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Inferior Mesenteric Lymph Nodes
The inferior mesenteric lymph nodes consist of: * (a) small glands on the branches of the left colic and sigmoid arteries * (b) a group in the sigmoid mesocolon, around the superior hemorrhoidal artery * (c) a pararectal group in contact with the muscular coat of the rectum Structure The inferior mesenteric lymph nodes are lymph nodes present throughout the hindgut. Function The inferior mesenteric lymph nodes drain structures related to the hindgut. The lymph nodes drain into the superior mesenteric lymph nodes and ultimately to the preaortic lymph nodes. Lymph nodes surrounding the inferior mesenteric artery drain directly into the preaortic nodes. They drain the descending colon and sigmoid parts of the colon and the upper part of the rectum. Clinical significance Colorectal cancer may metastasise to the inferior mesenteric lymph nodes. For this reason, the inferior mesenteric artery may be removed in people with lymph node-positive cancer. This has been proposed since at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Preaortic Lymph Node
The preaortic lymph nodes lie in front of the aorta, and may be divided into celiac lymph nodes, superior mesenteric lymph nodes, and inferior mesenteric lymph nodes groups, arranged around the origins of the corresponding arteries. The celiac lymph nodes are grouped into three sets: the gastric, hepatic and splenic lymph nodes. These groups also form their own subgroups. The superior mesenteric lymph nodes are grouped into three sets: the mesenteric, ileocolic and mesocolic lymph nodes. The inferior mesenteric lymph nodes have a subgroup of pararectal lymph nodes. The preaortic lymph nodes receive a few vessels from the lateral aortic lymph nodes, but their principal afferents are derived from the organs supplied by the three arteries with which they are associated–the celiac, superior and inferior mesenteric arteries. Some of their efferents pass to the retroaortic lymph nodes, but the majority unite to form the intestinal lymph trunk, which enters the cisterna chyli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superior Mesenteric Lymph Nodes
The superior mesenteric lymph nodes may be divided into three principal groups: * mesenteric lymph nodes * ileocolic lymph nodes * mesocolic lymph nodes Structure Mesenteric lymph nodes The mesenteric lymph nodes or mesenteric glands are one of the three principal groups of superior mesenteric lymph nodes and lie between the layers of the mesentery. They number from one hundred to one hundred and fifty, and are sited as two main groups: * one ileocolic group lying close to the wall of the small intestine, among the terminal twigs of the superior mesenteric artery; * a second larger mesocolic group placed in relation to the loops and primary branches of the vessels. Ileocolic lymph nodes The ileocolic lymph nodes, from ten to twenty in number, form a chain around the ileocolic artery, but tend to subdivide into two groups, one near the duodenum and the other on the lower part of the trunk of the artery. Where the vessel divides into its terminal branches the chain is broken ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metastasise
Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then, are metastases (mets). It is generally distinguished from cancer invasion, which is the direct extension and penetration by cancer cells into neighboring tissues. Cancer occurs after cells are genetically altered to proliferate rapidly and indefinitely. This uncontrolled proliferation by mitosis produces a primary heterogeneic tumour. The cells which constitute the tumor eventually undergo metaplasia, followed by dysplasia then anaplasia, resulting in a malignant phenotype. This malignancy allows for invasion into the circulation, followed by invasion to a second site for tumorigenesis. Some cancer cells known as circulating tumor cells acquire the ability to penetrate the walls of lymphatic or blood vessels, after which they are abl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colorectal Cancer
Colorectal cancer (CRC), also known as bowel cancer, colon cancer, or rectal cancer, is the development of cancer from the colon or rectum (parts of the large intestine). Signs and symptoms may include blood in the stool, a change in bowel movements, weight loss, and fatigue. Most colorectal cancers are due to old age and lifestyle factors, with only a small number of cases due to underlying genetic disorders. Risk factors include diet, obesity, smoking, and lack of physical activity. Dietary factors that increase the risk include red meat, processed meat, and alcohol. Another risk factor is inflammatory bowel disease, which includes Crohn's disease and ulcerative colitis. Some of the inherited genetic disorders that can cause colorectal cancer include familial adenomatous polyposis and hereditary non-polyposis colon cancer; however, these represent less than 5% of cases. It typically starts as a benign tumor, often in the form of a polyp, which over time becomes cancerous. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colon (anatomy)
The large intestine, also known as the large bowel, is the last part of the gastrointestinal tract and of the digestive system in tetrapods. Water is absorbed here and the remaining waste material is stored in the rectum as feces before being removed by defecation. The colon is the longest portion of the large intestine, and the terms are often used interchangeably but most sources define the large intestine as the combination of the cecum, colon, rectum, and anal canal. Some other sources exclude the anal canal. In humans, the large intestine begins in the right iliac region of the pelvis, just at or below the waist, where it is joined to the end of the small intestine at the cecum, via the ileocecal valve. It then continues as the colon ascending the abdomen, across the width of the abdominal cavity as the transverse colon, and then descending to the rectum and its endpoint at the anal canal. Overall, in humans, the large intestine is about long, which is about one-fifth o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Descending Colon
In the anatomy of humans and homologous primates, the descending colon is the part of the colon extending from the left colic flexure to the level of the iliac crest (whereupon it transitions into the sigmoid colon). The function of the descending colon in the digestive system is to store the remains of digested food that will be emptied into the rectum. The descending colon is on the left side of the body (barring any malformations). The term left colon is hypernymous to ''descending colon'' in precise use; many casual mentions of the left colon chiefly concern the descending colon. Structure The descending colon extends from the left colic flexure at the upper left part of the abdomen inferior-ward through the left hypochondrium and lumbar regions, along the outer border of the left kidney, ending at the level of the iliac crest at the lower left part of the abdomen, being contunued thenceforth as the sigmoid colon. It usually retroperitoneal (being lined by peritoneum on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Mesenteric Artery
In human anatomy, the inferior mesenteric artery, often abbreviated as IMA, is the third main branch of the abdominal aorta and arises at the level of L3, supplying the large intestine from the distal transverse colon to the upper part of the anal canal. The regions supplied by the IMA are the descending colon, the sigmoid colon, and part of the rectum. Structure Proximally, its territory of distribution overlaps (forms a watershed) with the middle colic artery, and therefore the superior mesenteric artery. The SMA and IMA anastomose via the marginal artery of the colon (artery of Drummond) and via Riolan's arcade (also called the "meandering artery", an arterial connection between the left colic artery and the middle colic artery). The territory of distribution of the IMA is more or less equivalent to the embryonic hindgut. Branches The IMA branches off the anterior surface of the abdominal aorta below the renal artery branch points, 3-4 cm above the aortic bifurcation (into t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Preaortic Lymph Nodes
The preaortic lymph nodes lie in front of the aorta, and may be divided into celiac lymph nodes, superior mesenteric lymph nodes, and inferior mesenteric lymph nodes groups, arranged around the origins of the corresponding arteries. The celiac lymph nodes are grouped into three sets: the gastric, hepatic and splenic lymph nodes. These groups also form their own subgroups. The superior mesenteric lymph nodes are grouped into three sets: the mesenteric, ileocolic and mesocolic lymph nodes. The inferior mesenteric lymph nodes have a subgroup of pararectal lymph nodes. The preaortic lymph nodes receive a few vessels from the lateral aortic lymph nodes, but their principal afferents are derived from the organs supplied by the three arteries with which they are associated–the celiac, superior and inferior mesenteric arteries. Some of their efferents pass to the retroaortic lymph nodes, but the majority unite to form the intestinal lymph trunk, which enters the cisterna chyli Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hindgut
The hindgut (or epigaster) is the posterior ( caudal) part of the alimentary canal. In mammals, it includes the distal one third of the transverse colon and the splenic flexure, the descending colon, sigmoid colon and up to the ano-rectal junction. In zoology, the term ''hindgut'' refers also to the cecum and ascending colon. Structure Blood supply Arterial supply is by the inferior mesenteric artery, and venous drainage is to the portal venous system. Lymphatic drainage is to the chyle cistern. Nerve supply The hindgut is innervated via the inferior mesenteric plexus. Sympathetic innervation is from the Lumbar splanchnic nerves (L1-L2), parasympathetic innervation is from S2-S4. Development Additional images File:Gray985.png, Abdominal part of digestive tube and its attachment to the primitive or common mesentery. Human embryo of six weeks. File:Gray1115.png, Tail end of human embryo twenty-five to twenty-nine days old. File:Illacme plenipes female with 170 segments and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Left Colic
The left colic artery is a branch of the inferior mesenteric artery distributed to the descending colon, and left part of the transverse colon. It ends by dividing into an ascending branch and a descending branch; the terminal branches of the two branches go on to form anastomoses with the middle colic artery, and a sigmoid artery (respectively). Structure The left colic artery usually represents the dominant arterial supply to the left colic flexure. Course The left colic artery passes to the left posterior to the peritoneum. After a short but variable course, it divides into an ascending branch and a descending branch. Branches and anastomoses Ascending branch The ascending branch passes superior-ward. It passes anterior to the (ipsilateral) psoas major muscle, gonadal vessels, ureter, and kidney; it passes posterior to the inferior mesenteric vein. Its terminal branches form anastomoses with those of the middle colic artery; it also forms anastomoses with the descendi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lymph Node
A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that include B and T cells. Lymph nodes are important for the proper functioning of the immune system, acting as filters for foreign particles including cancer cells, but have no detoxification function. In the lymphatic system a lymph node is a secondary lymphoid organ. A lymph node is enclosed in a fibrous capsule and is made up of an outer cortex and an inner medulla. Lymph nodes become inflamed or enlarged in various diseases, which may range from trivial throat infections to life-threatening cancers. The condition of lymph nodes is very important in cancer staging, which decides the treatment to be used and determines the prognosis. Lymphadenopathy refers to glands that are enlarged or swollen. When inflamed or enlarged, lymph nodes can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rectum
The rectum is the final straight portion of the large intestine in humans and some other mammals, and the Gastrointestinal tract, gut in others. The adult human rectum is about long, and begins at the rectosigmoid junction (the end of the sigmoid colon) at the level of the third sacral vertebra or the sacral promontory depending upon what definition is used. Its diameter is similar to that of the sigmoid colon at its commencement, but it is dilated near its termination, forming the rectal ampulla. It terminates at the level of the anorectal ring (the level of the puborectalis sling) or the dentate line, again depending upon which definition is used. In humans, the rectum is followed by the anal canal which is about long, before the gastrointestinal tract terminates at the anal verge. The word rectum comes from the Latin ''Wikt:rectum, rectum Wikt:intestinum, intestinum'', meaning ''straight intestine''. Structure The rectum is a part of the lower gastrointestinal tract ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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