Colon,Anorectum Disease,General Surgery The 2nd hospital of Shenyang Medical CollegeXu Daozhi,Parts of colon divided into cecum;ascending colon ;transverse colon;descending colon and sigmoid colon.average 150cm in length(120-200cm).diameter from cecum(7.5cm) to sigmoid colon(2.5cm).,Anatomy,Colon have three important anatomic landmarks: colic bands (teniae coli); haustra of colon; epiploic appendices (epiploicae appendices),Anatomy,Anatomy,the ileocecal valve: the terminal ileum empty into the cecum via the hepatic flexure and the splenic flexure rectum: up along with the sigmoid colon. down along with the anal canal.12 to 15cm in length. serve as a fecal reservoir. anal columns; anal valves and anal sinuses. anorectal line,Anatomy,anal canal: up is anorectal line, down is anus.1.5 to 2cm in length. the epithelium differ. the serrated dentate (or pectinate) line: demarcate rectum and anal canal (important anatomic landmarks) the importance show: upper is mucosa, autonomic nerve, no pain. below is skin, internal pudendal nerve, with keen pain.,Anatomy,blood supply differ: upper is superior rectal artery, inferior rectal artery. below is artery of anal canal. venous return differ: upper is superior rectal plexus superior rectal vein portal vein. below is inferior rectal plexus vein of anal canal inferior vena cava. lymphatic return differ: upper is aorta abdominalis nearby or the internal iliac lymph node. below is inguinal lymph node or external iliac node. white line: intermuscular groove.,Anatomy,rectum and anal canal musculature: the anal canal musculature with its sphincteric apparatus is the terminal muscular channel of the gastrointestinal tract. internal anal sphincter muscle is the continuation of the smooth circular layer of the rectum. external anal sphincter muscle is a continuous sheet of striated muscle constituting the pelvic floor. it divide into subcutaneous external anal sphincter muscle; superficial external anal sphincter muscle; deep external anal sphincter muscle. levator ani muscles: the puborectalis muscle; pubococcygeous muscle; illiococcygeous muscle. their fibers decussate medially form funnel-shaped.,Anatomy,anorectal ring: internal anal sphincter muscle; lower limb of longitudinal muscle of rectum; deep external anal sphincter muscle and proximal levator ani muscles (the puborectalis muscle). fecal incontinence. anorectal peripheral clearance: comprise much adipose connective tissue. easily infect anal fistula. up levator ani muscles : pelvirectal clearance; retrorectal clearance. below levator ani muscles : ischiorectal clearance; perianal clearance.,Anatomy,arterial supply and venous and lymphatic drainage of colon; rectum and anal canal: colon: right colon superior mesenteric artery (ileocolic artery; right colic artery; middle colic artery.) left colon inferior mesenteric artery (left colic artery and sigmoid artery). vein have the same name with artery,superior mesenteric vein inferior mesenteric vein,Anatomy,portal vein,Anatomy,colon lymphatic drainage: superior colic lymph nodes; paracolic lymph nodes; middle colic lymph nodes; central colic lymph nodes. colic nerve: parasympathetic nerve differ, right vagus; left pelvic nerve sympathetic nerve: superior mesenteric neuroplexus and inferior mesenteric neuroplexus.,Anatomy,rectum and anal canal: artery:upper of pectinate line is superior rectal artery; inferior rectal artery and median sacral artery. below of pectinate line is anal canal artery. vein:upper of pectinate line is superior rectal plexus superior rectal vein inferior mesenteric vein portal vein. below of pectinate line is inferior rectal plexus inferior rectal vein and anal vein internal iliac vein and internal pudendal vein interior vena cava.,Anatomy,rectum and anal lymphatic drainage: most important path is superior rectal artery nearby inferior mesenteric artery. nearby inferior rectal artery internal iliac lymph nodes. down anal artery and internal pudendal artery internal iliac lymph nodes. below of pectinate line: downward pass through perineum and inner thigh inguinal lymph nodes external iliac lymph nodes. ischiorectal clearance nearby obturator artery internal iliac lymph nodes.,nerve：upper is autonomic nerve (sympathetic nerve and parasympathetic nerve) below is internal pudendal nerve,Anatomy,physiology,colonic major function: absorb water; gluscose;electrolyte and bile acid. store and transport soil. rectal major function: defecation; absorbtion and secretion.,Anorectal examination,Posture anal inspection Rectal palpation Anoscope; sigmoidoscope; fibercoloscope examination X-ray;CT;MRI and rectal ultrasound endoscope examination Anorectal function examinatin,Rectal inspection: Digital examination of rectum: simple and important clinical examination ways. may find: hemorrhoids; anal fistula; rectal polyp; anorectal cancer,Anorectal examination,Sigmoid volvulus,sigmoid mesentery as axle volvulus sigmoid colon is most commonly involved, occupy 65%-80%. cecum and transverse colon may occur. Old people(60y):young people=20:1,