The classification of the large intestine, large intestine of adult total length 1.5m, including the cecum, appendix, ascending colon, transverse colon, descending colon, sigmoid colon, rectum and dirty tube. The first six classified as part of the colon. Colorectal cancer (cancer of the large intestine) is a common cancer of the digestive tract.
(A) of the colon
Often clinically divided into two halves to the colon. Right colon including the cecum, ascending colon and transverse colon, the right 2 / 3; left colon including the transverse colon, left 1 / 3, descending colon and sigmoid colon. Right colon large intestine, including appendix lumen diameter 7.5cm. Left colon small intestine, B is the narrowest point of the junction of the rectum, the diameter of only 2.5cm, the area was most likely to lead to cancer tumor obstruction. When complete obstruction of the colon for tumors, because the back flap of the existence of the cecum, the obstruction of the colon was closed at both ends of the state, and because many bacteria in the colon, leaving the more serious obstruction. Closest to the anterior abdominal wall cecum, transverse colon and sigmoid colon with a large mesangial and activity, they are used clinically for colostomy.
Right colon from the superior mesenteric artery, trunk back to the colic artery, right colic artery and middle colic artery; left colon by the inferior mesenteric artery. Separation of the left colic artery and two or three sigmoid arteries, veins and arteries accompanied by the line, respectively, superior mesenteric vein and superior mesenteric vein and portal vein sinks. Colorectal mucosa does not exist in the lymphatic vessels, lymphatic network is started from the lower membrane of Mongolia, the colon wall lymph nodes, colon lymph nodes, intermediate nodes included in the central lymph nodes.
Right colon by the vagus nerve, left colon by the pelvic nerve. Sympathetic nerve fibers were from the lumbar sympathetic ganglia.
The main function of the right colon is to absorb water, glucose, per unit of salt and some bile acids, left colon mainly manure storage and excretion. In addition, the colon can secrete an alkaline fluid to lubricate the mucous membrane of Mongolia, but also the secretion of several gastrointestinal system hormones.
(B) of the rectum, anal canal
Rectum is about 12, "15cm. Rectum is not straight, side view and perineum are offering music song; front view have the right from top to bottom, left and right bending. Rectum above the bend, so completely free rectal cancer after surgery rectal tumor margin to the edge of the door from the extended Rainbow 2-3cm, so that some of the preoperative management that need to be dirty abdominal perineal rectal resection of rectal cancer cases, this time the door can be diverted to keep Hong surgery.
Mesorectum refers to the visceral pelvic fascia, the connective tissue surrounding the rectum and the surrounding fat, blood vessels and nerves, and lymphatic tissues. Department of membrane lesions were disseminated rectal cancer confined to the visceral pelvic fascia, within the. Therefore, the requirements of complete resection of rectal cancer surgery and its mesentery, to avoid local recurrence.
Dirty tube about 3cm, the access rectum, the lower is the dirty door. Pipe around the embryo within the sphincter around. Sphincter is voluntary muscle, was the rectum and anus levator muscle longitudinal muscle fibers through the skin into the Ministry of shallow and deep. The most important of which deep, combined with the puborectalis muscle, attached to the pubic symphysis, the contraction to move the lift. Cut off, can cause fecal incontinence.
Siphon from the rectal rectal artery rectal artery, arteries, and proactive management in the embryo arterial supply. There are two dirty tube rectal venous plexus; rectum above the dentate line integration of rectal venous plexus on the superior mesenteric vein, portal vein vein flow; dentate line of the rectal venous plexus after the integration of small branches, directly into the vein through the rectum Ru vein or rectal vein, pudendal vein and the vein into Confucianism.
Rectum rectal cancer are up next to the lymph nodes, lymph node rectal artery, superior mesenteric artery lymph node metastasis as the main lymphatic channels. Above the peritoneal fold-up of rectal cancer only when cancer lymphatic drainage pathway is blocked only when a down to the rainbow ischial rectal fossa lymph node artery, the two sides to the lateral ligament of the rectum within the lymph nodes under the artery and vein, and then to the obturator lymph node metastasis. However, the following rectal peritoneal fold up the lymphatic drainage pathways in addition, it also exists to the second side to the bottom of drainage channels. Therefore, peritoneal fold of rectal cancer should consider the following abdominal perineal resection.
Siphon and the embryo can be next to the skin lymphatic drainage to the groin lymph nodes, lymph nodes and then up to the outside regret; also be dirty by the ischial rectal fossa lymph node artery, and then to the lymph nodes of Confucianism.
Rectum dentate line by spinal nerve, sensitive; above the dentate line dominated by the autonomic nervous system. Yang and direct nerve surgery is related to the lower abdomen and pelvic nerve visceral nerve, they were Division ejaculation and erectile function, surgery should be careful not to damage.
The classification of the large intestine, rectum and anal canal is the main physiological function of bowel and rectum that secrete mucus to help the feces. Rectum also can absorb a small amount of water, salt, glucose and some drugs. The lower rectum is the principal place of defecation reflex site, is an important part of bowel function. Thus, total removal of the rectum, even if retained sphincter, defecation reflex part because of the loss can still occur fecal incontinence.