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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. Afferents The inferior mesenteric lymph nodes drain structures related to the hindgut; they receive lymph from the descending colon, sigmoid colon, and proximal part of the rectum. Efferents They 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. 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 le ... [...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 lymph nodes, gastric, hepatic lymph nodes, hepatic and splenic lymph nodes. These groups also form their own subgroups. The superior mesenteric lymph nodes are grouped into three sets: the mesenteric lymph nodes, mesenteric, ileocolic lymph nodes, 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 artery, celiac, superior mesenteric artery, superior and inferior mesenteric artery, inferior mesenteric arteries. ... [...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 continued thenceforth as the sigmoid colon. It is usually retroperitoneal (being lined by perit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metastasise
Metastasis is a pathogenic agent's spreading 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 (CTCs), are able to penetrate the walls of lymphatic or blood vessels, and circulate throug ... [...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 (anatomy), colon or rectum (parts of the large intestine). Signs and symptoms may include Lower gastrointestinal bleeding, blood in the stool, a change in bowel movements, weight loss, abdominal pain and fatigue. Most colorectal cancers are due to lifestyle factors and 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 (drug), 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 adenoma, benign tumor, often in the form of a colorectal poly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Mesenteric Artery
In human anatomy, the inferior mesenteric artery (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 Origin The IMA arises from the anterior aspect of the abdominal aorta. Its origin is situated at the L3 vertebral level ( subcostal plane), below the origins of the two renal arteries, 3-4 cm above the aortic bifurcation, at the level of the umbilicus, and posterior to the inferior border of the horizontal (III) part of the duodenum. Branches Along its course, the IMA has the following branches: All these arterial branches further divide into arcades which then supply the colon at regular intervals. Relations The IMA is accompanied along its course by a similarly named vein, the inferior mesenteric vein, which drains into the ... [...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 The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ... 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 ... [...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] |
Sigmoid Colon
The sigmoid colon (or pelvic colon) is the part of the large intestine that is closest to the rectum and anus. It forms a loop that averages about in length. The loop is typically shaped like a Greek letter sigma (ς) or Latin letter S (thus ''sigma'' + '' -oid''). This part of the colon normally lies within the pelvis, but due to its freedom of movement it is liable to be displaced into the abdominal cavity. Structure The sigmoid colon begins at the superior aperture of the lesser pelvis, where it is continuous with the iliac colon, and passes transversely across the front of the sacrum to the right side of the pelvis. It then curves on itself and turns toward the left to reach the middle line at the level of the third piece of the sacrum, where it bends downward and ends in the rectum. Its function is to expel solid and gaseous waste from the gastrointestinal tract. The curving path it takes toward the anus allows it to store gas in the superior arched portion, enabling ... [...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 a ... [...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 desc ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rectum
The rectum (: rectums or recta) is the final straight portion of the large intestine in humans and some other mammals, and the gut in others. Before expulsion through the anus or cloaca, the rectum stores the feces temporarily. 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 '' rēctum intestīnum'', meaning ''straight intestine''. Struc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
