局部解剖学结肠下区课件

局局 部部 解解 剖剖 学学 Topographical AnatomyTopographical Anatomy Department of Anatomy , Jilin UniversityDepartment of Anatomy , Jilin University 石岫昆石岫昆 Xiukun Shi 2007.02.08Xiukun Shi 2007.02.08 Section 6Section 6 结肠下区结肠下区 Infracolic Infracolic CompartmentCompartment Infracolic compartment lies between transverse Infracolic compartment lies between transverse colon with its mesocolon and superior aperture of colon with its mesocolon and superior aperture of lesser pelvis. lesser pelvis. It contains It contains jejunum, ileum, jejunum, ileum, cecum, vermiform cecum, vermiform appendix, colon appendix, colon and other viscera.and other viscera. I. I. 空肠及回肠空肠及回肠 Jejunum and ileumJejunum and ileum I) I)位置位置 Location Location Jejunum and ileum are Jejunum and ileum are continuous coiled part of small intestine, extend from continuous coiled part of small intestine, extend from duodenojejunalduodenojejunal flexure to cecum flexure to cecum and occupy most and occupy most part of infracolic part of infracolic partment. They probably They probably average about average about 56 meters in 56 meters in length.length. Jejunum comprises Jejunum comprises upper 2/5 of whole upper 2/5 of whole length, and ileum length, and ileum lower 3/5. lower 3/5. Jejunum located Jejunum located upper left abdominal upper left abdominal cavity and ileum in cavity and ileum in lower right. lower right. The small part of The small part of ileum usually passes ileum usually passes also into pelvis.also into pelvis. MeckelMeckel憩室憩室 ( (Meckels diverticulum)Meckels diverticulum) Persistence of Persistence of proximal portion of yolk sac (vitelline duct) common proximal portion of yolk sac (vitelline duct) common malformation of digestive tract (2malformation of digestive tract (2 4%) more prevalent 4%) more prevalent in males. About 2in males. About 2 5cm long and located 305cm long and located 30 100cm100cm from from ileocecal valve. ileocecal valve. Usually asymptomatic but: Usually asymptomatic but: May becomeMay become inflamed (mimicking inflamed (mimicking appendcitis) or appendcitis) or cause intestinal cause intestinal obstruction by obstruction by compressing compressing adjacent intestinal adjacent intestinal loops.loops. II)II)肠系膜肠系膜 MesenteryMesentery It consists of two layers It consists of two layers of peritoneum, and of peritoneum, and contains jejunal and ileal contains jejunal and ileal blood vessels, as wall as blood vessels, as wall as lymph nodes and some lymph nodes and some fat. fat. Mesentery is fan- Mesentery is fan- shaped and allows coils shaped and allows coils of intestine considerable of intestine considerable freedom of movement. freedom of movement. Root of mesenteryRoot of mesentery begins begins from duodenojejunal from duodenojejunal flexure, which somewhat at flexure, which somewhat at left side of second lumber left side of second lumber vertebra.vertebra. Its line of attachment to Its line of attachment to posterior abdominal wall posterior abdominal wall extends obliquely downwards extends obliquely downwards and ends to ileocolic and ends to ileocolic junction, which is junction, which is approximately at level of approximately at level of right sacroiliac joint. It is right sacroiliac joint. It is about 15 cm in length. about 15 cm in length. III)III) 血管血管 Blood vesselsBlood vessels Entire jejunoileum is supplied by branches of Entire jejunoileum is supplied by branches of superior superior mesenteric a.,mesenteric a., which arises from which arises from abdominal aorta at levelabdominal aorta at level of L1, of L1, posterior to neck of pancreas.posterior to neck of pancreas. It descends anterior to It descends anterior to horizontal part of duodenum horizontal part of duodenum and enters root of mesentery to and enters root of mesentery to right iliac fossa. right iliac fossa. It gives off 1218 intestinal It gives off 1218 intestinal arteries from its left side to arteries from its left side to jejunoileum.jejunoileum. Jejunal and ileal arteriesJejunal and ileal arteries branch and anastomose with branch and anastomose with each other to form a series of arterial arcades, from which each other to form a series of arterial arcades, from which further branchesfurther branches form a second,form a second, a a third and even a third and even a fourthfourth tier of tier of arcades. arcades. Last tier of Last tier of arcades send arcades send straight arteries straight arteries to each side of to each side of small intestine. small intestine. Jejunum ileum Vasa recta Veins of small intestine Veins of small intestine unite to form superior unite to form superior mesenteric v. and then join splenic v. to form hepatic mesenteric v. and then join splenic v. to form hepatic portal v. posterior to neck of pancreas.portal v. posterior to neck of pancreas. Jejunum and ileumJejunum and ileum CharacteristicJejunumIleum PositionUpper 2/5Lower 3/5 DiameterGreaterLess WallThickerThin Circular foldsLarger, numerous and large villi Fewer，smaller and less abundant villi VascularityGreaterLess Vasa recta Long Short Colour Deeper redPaler pink Lymphatic folliclesSolitaryAggregated Fat in mesentery LessMore II. II. 盲肠和阑尾盲肠和阑尾 CecumCecum and vermiform appendix and vermiform appendix I) I)盲肠盲肠 CecumCecum is is blind sac, first part of large intestine, blind sac, first part of large intestine, withwith largest diameter and largest diameter and thinnest wall, thinnest wall, usually usually lyinglying in right in right iliac fossa, iliac fossa, rarely in lesser pelvis or rarely in lesser pelvis or at a higher level, even to at a higher level, even to right colic flexure.right colic flexure. It is about 68 cm in It is about 68 cm in length and width. length and width. Superiorly, it joins Superiorly, it joins ascending colon.ascending colon. Cecum is an intraperitoneal organ, almost surrounded Cecum is an intraperitoneal organ, almost surrounded by peritoneum. It is relatively mobile, and sometimes by peritoneum. It is relatively mobile, and sometimes cecum have a short mesocolon, cecum becomes more cecum have a short mesocolon, cecum becomes more mobile, called mobile, called “mobile cecum”,“mobile cecum”, and easily to herniate or and easily to herniate or volvulate. volvulate. Terminal ileum opens into medial and posterior aspect Terminal ileum opens into medial and posterior aspect of cecum, and is partly invaginated into cecum to form of cecum, and is partly invaginated into cecum to form folds above and below opening, called folds above and below opening, called Ileocecal valve (Ileocecal valve (回回 盲瓣盲瓣) ). . It takes part in preventing It takes part in preventing reflux of cecal contents into reflux of cecal contents into ileum, and controlling speed ofileum, and controlling speed of elimination elimination of ileal of ileal contents contents into o colon. I) I) 阑尾阑尾 Vermiform appendixVermiform appendix is a narrow, is a narrow, blind worm-blind worm- like tubelike tube, usually 68 cm in length, usually 68 cm in length, 0.5cm in diameter, 0.5cm in diameter, but but extremes varying from 220 cm have been recorded. extremes varying from 220 cm have been recorded. It opens into posteromedial aspect of cecum about 2 cmIt opens into posteromedial aspect of cecum about 2 cm below ileoceal below ileoceal valve valve ( ( orifice). Base of orifice). Base of appendix lies at appendix lies at point of convergence point of convergence of three colic bands of three colic bands (used as a guide to (used as a guide to find appendix find appendix during operation).during operation). Surface markingSurface marking of base is at the so-called of base is at the so-called McBurneys McBurneys pointpoint which is at junction of lateral and middle thirds of which is at junction of lateral and middle thirds of line joining right anterior superior iliac spine and line joining right anterior superior iliac spine and umbilicus. umbilicus. This point representsThis point represents a fixed point on abdominal wall, a fixed point on abdominal wall, it is area of greatest tenderness it is area of greatest tenderness in appendicitis. in appendicitis. Special positionSpecial position is rarely is rarely as as high position appendix (under high position appendix (under liver), extraperitoneal appendix, liver), extraperitoneal appendix, and left lower abdominal and left lower abdominal position appendix. position appendix. Appendix Appendix is entirely covered by peritoneum and has a is entirely covered by peritoneum and has a triangulartriangular mesentery mesentery ( (阑尾系膜阑尾系膜 Mesoappendix)Mesoappendix) which which extends from terminal part of ileum to appendix. extends from terminal part of ileum to appendix. Tip Tip of appendix is very variable in position, according to of appendix is very variable in position, according to statistical data of Chinese people, frequently it lies at statistical data of Chinese people, frequently it lies at following position: Preileal position (in 28%), Pelvicfollowing position: Preileal position (in 28%), Pelvic position (in 26%), position (in 26%), Retrocecal position Retrocecal position (in 24%), Retroileal (in 24%), Retroileal position (in 8%), position (in 8%), Subcecal position Subcecal position (in 6%).(in 6%). Appendicular arteryAppendicular artery arises from ileocolic a. arises from ileocolic a. Most of appendicular Most of appendicular arteries are single (in arteries are single (in 92%). It runs in free 92%). It runs in free margin of meseoappendix margin of meseoappendix then along wall of then along wall of appendix. appendix. Appendicular veinAppendicular vein drains into hepatic portal vein via drains into hepatic portal vein via superior mesenteric veins. In clinic, when appendix superior mesenteric veins. In clinic, when appendix becomes suppurative appendicitis, bacterial emboli may becomes suppurative appendicitis, bacterial emboli may enter liver and hepaticenter liver and hepatic abscess.abscess. During During appendicectomy, do appendicectomy, do not extrude inflamed not extrude inflamed appendix to prevent appendix to prevent infective emboli from infective emboli from entering into blood entering into blood flow.flow. III.III.结肠结肠 ColonColon I) Features of colonI) Features of colon 1. 1. 结肠带结肠带 Colic bandsColic bands There are There are three band-like longitudinal colic bands on wall of cecum three band-like longitudinal colic bands on wall of cecum and colon. and colon. They converge They converge at base of at base of vermiform vermiform appendix and appendix and become become continuous with continuous with its outer layer of its outer layer of muscle.muscle. 2. 2.结肠袋结肠袋 Haustra of colonHaustra of colon Because lengths of colic Because lengths of colic bands are shorter than that large intestine, large intestine bands are shorter than that large intestine, large intestine is typically sacculated, forming haustra of colon.is typically sacculated, forming haustra of colon. 3. 3.肠脂垂肠脂垂 Epiploic appendicesEpiploic appendices They are small projecting They are small projecting pouches of pouches of peritoneum filled peritoneum filled with fat, and are with fat, and are numerousnumerous on on transverse and transverse and sigmoid colons, but sigmoid colons, but are absent on cecum, are absent on cecum, appendix is capillaries of alimentary canal; otherother is sinusoid of liver There are no is sinusoid of liver There are no functioning valves in hepatic portal functioning valves in hepatic portal system When pressure in hepatic system When pressure in hepatic portal v. ascends, blood can flow portal v. ascends, blood can flow adversely.adversely. II) II)属支属支 TributariesTributaries Hepatic portal v. have 7 Hepatic portal v. have 7 tributaries: 1.tributaries: 1.肠系膜上静脉肠系膜上静脉 superior mesenteric v., 2.superior mesenteric v., 2.脾静脾静 脉脉 splenic v., 3.splenic v., 3.肠系膜下静脉肠系膜下静脉 inferior mesenteric v., 4.inferior mesenteric v., 4.胃胃 左静脉左静脉 left gastric v., 5.left gastric v., 5.胃右胃右 静脉静脉 right gastric v., 6.right gastric v., 6.胆囊静胆囊静 脉脉 cystic v., 7.cystic v., 7.附脐静脉附脐静脉 paraumbilical v paraumbilical v All tributaries except cystic All tributaries except cystic and paraumbilical, accompany and paraumbilical, accompany their corresponding arteries, their corresponding arteries, and drain venous blood from and drain venous blood from territory of arteries.territory of arteries. III) III)门腔静脉系之间的吻合门腔静脉系之间的吻合 Portal-Systemic AnastomosesPortal-Systemic Anastomoses Veins between hepatic portal and Veins between hepatic portal and systemic veins, there are many systemic veins, there are many collateral anastomoses. Normally, collateral anastomoses. Normally, these anastomoses are unopened. In these anastomoses are unopened. In portal hypertension, some factors portal hypertension, some factors increase venous pressure in portal increase venous pressure in portal system, some of portal drainage may system, some of portal drainage may then back up and pass through then back up and pass through portal-systemic anastomoses in a portal-systemic anastomoses in a reverse direction into systemic veins. reverse direction into systemic veins. Four important areas of portal-systemic anastomoses Four important areas of portal-systemic anastomoses occur: occur: 1. At lower end of oesophagus1. At lower end of oesophagus Hepatic portal v. left gastric v. Hepatic portal v. left gastric v. esophageal venous plexusesophageal venous plexus esophageal esophageal v. azygos v. superior vena cavav. azygos v. superior vena cava 2.At rectal venous plexus2.At rectal venous plexus Hepatic portal v. splenic v. Hepatic portal v. splenic v. inferior mesenteric v. superior rectal inferior mesenteric v. superior rectal v. v. rectal venous plexusrectal venous plexus inferior inferior rectal and anal v. internal iliac v. rectal and anal v. internal iliac v. common iliac mon iliac v. inferior vena cava inferior vena cava 3. At periumbilical venous plexus 3. At periumbilical venous plexus Hepatic portal v. paraumbilical v. Hepatic portal v. paraumbilical v. periumbilical venous plexusperiumbilical venous plexus following following routes:routes: thoracoepigastric v. thoracoepigastric v. lateral lateral thoracic v axillary v subclavian v thoracic v axillary v subclavian v brachiocephalic v superior vena cava; brachiocephalic v superior vena cava; superior epigastric v. superior epigastric v. internal thoracic v. internal thoracic v. brachiocephalic v. superiorvena cava; brachiocephalic v. superiorvena cava; superficial epigastric v. superficial epigastric v. great great saphenous v. femoral v. external iliac saphenous v. femoral v. external iliac v. common iliac v. inferior vena cava; v. common iliac v. inferior vena cava; inferior epigastric v. inferior epigastric v. external iliac v. external iliac v. common iliac v. inferior vena cava. common iliac v. inferior vena cava. 4. Portal-retroperitoneal 4. Portal-retroperitoneal anastomosisanastomosis anastomoses through unions between anastomoses through unions between small veinssmall veins At posterior wall of abdomen, At posterior wall of abdomen, small tributaries of sup. and inf. small tributaries of sup. and inf. mesenteric v. anastomose with small mesenteric v. anastomose with small branches of inferior diaphragm v., renal v. branches of inferior diaphragm v., renal v. and testicular v.; and testicular v.; anastomoses through anastomoses through vertebral venous plexusvertebral venous plexus At posterior wall At posterior wall of abdomen, small tributaries of sup. 12th rib is border of T11 to L2; 12th rib is behind its middle part of post behind its middle part of post surface. surface. Right kidneyRight kidney lies at level from lies at level from upper border of T12 to L3; 12th rib upper border of T12 to L3; 12th rib crosses its upper part of post surface.crosses its upper part of post surface. Renal hilum(Renal hilum(肾门肾门 ) ) is at level of spine of 1st lumbar is at level of spine of 1st lumbar vertebra, and 5 cm lateral to it, or at angle where lateral vertebra, and 5 cm lateral to it, or at angle where lateral border of erector spinae crosses 12th rib border of erector spinae crosses 12th rib (called Renal (called Renal angleangle肾角肾角 or Renal region ).or Renal region ). Tenderness or percussing Tenderness or percussing pain caused by kidney disease is localized to this renal pain caused by kidney disease is localized to this renal angle.angle. 2. 2.毗邻毗邻 RelationRelation Upper poleUpper pole of kidney is covered by of kidney is covered by suprarenal gland. suprarenal gland. Posteriorly Posteriorly Each kidney lies Each kidney lies on fouron four muscles muscles (Diaphragm and (Diaphragm and pleural cavity, Psoas major,pleural cavity, Psoas major, Quadratus lumborum Quadratus lumborum and and transversus abdominis)transversus abdominis) and three and three nerves nerves (Subcostal, Iliohypogastric, (Subcostal, Iliohypogastric, Ilioinguinal nerve)Ilioinguinal nerve). . MedialMedial Left kidney Left kidney abdominal aorta; Right kidneyabdominal aorta; Right kidney inferior ceva vana.inferior ceva vana. AnteriorlyAnteriorly Left kidneyLeft kidney is in contact with Stomach and is in contact with Stomach and Spleen (superior), Tail of pancreas (middle), and Coils of Spleen (superior), Tail of pancreas (middle), and Coils of jejunum jejunum Right kidneyRight kidney is is in contact with Right lobe of liver (superior), Descending in contact with Right lobe of liver (superior), Descending part of duodenum (middle), and Right colic flexure part of duodenum (middle), and Right colic flexure (inferiorly). (inferiorly). Structures which ent