Abdominal wall

1. Abdominal wall 山东大学医学院 解剖教研室 李振华

2. Anterior wall Layers ( from superficial to deep) • Skin • Superficial fascia • Anterolateral muscles • Transversalis fascia 腹横筋膜 • Extraperitoneal fascia 腹膜下筋膜 • Parietal peritoneum 壁腹膜

3. Superficial fascia－divisions below umbilicus • Superficial fatty layer (Camper’s) • Membranous layer (Scarpa’s)

4. Muscles of abdomen Anterolateral group • Obliquus externus absominis 腹外斜肌 • Oblequus enternus abdominis腹内斜肌 • Transversus abdominis腹横肌 • Rectus abdominis 腹直肌

5. Posterior group • Quadiatus lumborum 腰方肌 • Psoas major 腰大肌

6. Obliquus externus absominis 腹外斜肌 General direction of fibers: downward, forward and medially (run down and inward) Structures • Inguinal ligament腹股沟韧带 • Lacunar ligament腔隙韧带 • Superficial inguinal ring腹股沟浅环 －triangular-shaped defect in aponeurosis of obliquus externus abdominis above pubic tubercle

8. Obliquus internus abdominis 腹内斜肌 • Deep to obliquus externus abdominis • General direction of fibres: upwards, forwards and medially

9. Transversels abdominis腹横肌 • Deep to obliquus internus

10. Inguinal falx 腹股沟镰: arch over spermatic cord, inserted with transverses abdominis fiber into medial part of pecten of pubis • Cremaster 提睾肌: around the spermatic cord and testis

11. Rectus abdominis 腹直肌 • Position: lie on to either of midline • Origin: pubic crest and symphysis • Insertion: xiphoid and 5th-7th costal cartilages • Has 3-4 tendinous intersections腱划 • linea semiluaris半月线

12. Similar functions for above four pairs of muscles • Support and compress the abdominal viscera • Increase intra-abdominal pressure, aid in expulsive efforts-vomiting, coughing, sneezing, defecation, urination and childbirth. • Depress ribs, assist in (the act of force(4)expiration. • Flex, lateral flex, and rotate vertebral column

13. Sheath of rectus abdominis 腹直肌鞘 Ant layer－formed by fusion of aponeurosis of obliquus externus abdominis and anterior leaf of aponeurosis of obliquus internus abdominis Post layer • Formed by fusion of posterion leaf of aponeurosis of obliquus internus abdominis and aponeurosis of transverses abdominis • Absent in about 4-5cm below the umbilicus, where aponeuroses of all three muscles form anterior layer the lower free border named arcuate line • Below this line rectus abdominis in contact with transverse fascia

14. Linea alba 白线 －tendinous raphe between right and left recti from xiphoid to pubic symphysis.

15. Inguinal region 腹股沟区 Boundaries • Inguinal ligament • Lateral margin of rectus abdominis • A horizontal line stretching from anterior iliac spine to laeral margin of rectus abdominis

16. Descent of testes Seven-week embryo showing the testis before its descent from the dorsal abdominal wall

17. Fetus at 28 week the testis passing through the inguinal canal

18. Newborn

19. Inguinal canal腹股沟管 Position: oblique passage, 4cm long, located 1.5cm above medial half of inguinal lig.

20. Boundaries • Ant wall • Aponeurosis of obliquus externus abdominis • Obliquus internus abdominis (lateral third of wall)

21. Post wall • Transverse fascia • Inguinal flax medially • Roof－arched lower fibers of obliquus internus and transversua abdominis • Floor－inguinal lig．

22. Two openings • Superficial inguinal ring 腹股沟浅环 • Deep inguinal ring 腹股沟深环 －defect in transverse fascia 1.5cm above midpoint of inguinal ligament

23. Structures passing through the inguinal canal • Spermatic cord精索and ilioinguinal nerve髂腹股沟神经in males • Round ligament of uterus子宫圆韧带and ilioinguinal nerve髂腹股沟神经in females

24. Inguinal Triangle (of Hesselbach) 腹股沟三角 Boundaries • Inguinal ligament inferiorly • Lateral border of rectus abdominis medially • Inferior epigastric artery laterally

25. Indirect inguinal heinia and direcet inguinal heinia

26. Superficial vessels and cutaneous nerves • Arteries • Superficial epigastric a. • Superficial iliac circumflex a. • Veins • Thoracoepigastric v. • Superficial epigastric v. • Cutaneous nerves • Anterior and lateral cutaneous n. of lower six thoracic • Iliohypogastric n. (first lumb nerves)

27. Deep vessels and nerves Arteres • Superior and inferior epigastric arteris • Lower posterior intercostal a. • Subcostal a. • Four lumbar a.

28. Nerves • Iliohypogastric n. 髂腹下神经 • Arises from lubar plexus • Passes forward in the interval between obliquus internus and tranversus abdominis • Pieces obliquus internus abdominis 2.5 cm medial to anterior superior iliac spine • Pieces aponeurosis of obliquus externus abdominisabout 2.5 cm above superficial inguinal ring • Ilioinguinal n. 髂腹股沟神经 • Runs parallel with iliohypogastric n. at a lower level • Enters inguinal canal and emerges through superficial inguinal ring • Genitofemoral n. 生殖股神经

29. Median or midline incision Subcostal incision Muscle-splitting incision Left paramedian incision Transverse incision Suprapubic incision Layer ?

30. Abdomen 2 山东大学医学院 解剖教研室 李振华

31. Abdominal aorta 腹主动脉 • Continuation of thoracic aorta at aortic hiatus of diaphragm in front of T12 • Terminates at lower border of L4 vertebra by dividing into right and left common iliac arteries

32. Parietal branches • Inferior phrenic a.膈下动脉(one pair) • Lumbar a.腰动脉(four pairs of arteries that supply the posterior abdominal wall) • Median sacral a. 骶正中动脉

33. Visceral branches • Paired branches • Middle suprarenal artery 肾上腺中动脉 • Renal artery 肾动脉 • Testicular (ovarian) artery 睾丸（卵巢）动脉

34. Unpaired branches • Celiac trunk腹腔干 －a short thick vessel that arises from the front of aorta, at the level of T12 • Superior mesenteric a. 肠系膜上动脉－arises from the front of aorta, at the level of L2 • Inferior mesenteric a. 肠系膜下动脉 －arises from the front of aorta, at level of L3

35. Left gastric a. Left branch Right branch Short gastric a. Common hepatic a. Cystic a. Splenic a. Right gastric a. Proper hepatic a. Gastroduodenal a. Splemic branches Left gastrioeploic a. Right gastroepiploic a. Superior pancreaticoduodenal a. Celiac trunk

36. Celiac trunk

37. Superior Mesenteric v. Middle colic a. Inf. pancresticodudenal a. Superior mesenteric a. Right colic a. Jejunal and ileal a. Ileocolic a. Appendicular a.

38. Inferior mesenteric v. Inferior mesenteric a. Left colic a. Sigmoid a. Superior rectal a.

39. Colic marginal artery

40. Relations of abdominal aorta • Anteriorly (from above downward) • Pancreas • Ascending part of duodenum • Radix of mesentery • Posteriorly • Upper four lumber vertebrae • On its right • Inferior vena cava • On its left • Left sympathetic trunk

41. Veins of abdomen and pelvis Internal iliac vein 髂内静脉 • Parietal tributaries: accompany with arteries • Visceral tributaries →superior rectal vein→inferior mesenteric v. ①Rectal venous plexus →inferior rectal vein→internal iliac v. 直肠静脉丛 →anal vein→internal pudendal v. ②Vesical venous plexus 膀胱静脉丛→vesical v. ③Uterine venous plexus 子宫静脉丛→uterine v.

42. External iliac vein髂外静脉– accompany the artery • Common iliac vein髂总静脉– formed by union of internal and external iliac veins in front of sacroiliac joint, end upon L4~L5 by uniting each other to form inferior vena cava

43. Inferior vena cava下腔静脉 • Formed by union of two common iliac veins anterior to and just to the right of L4~L5 • Ascends on the right side of aorta, pierces vena cava foramen of diaphragm opposite the T8 and drains into the right atrium • Conveys blood from the whole body below the diaphragm to the right atrium

44. Chief tributaries • Parietal • Paired inferior phrenic v. 膈下静脉 • paired lumbar v. 腰静脉(four) • Visceral • Right and left renal veins 左、右肾静脉 • Right suprarenal vein 右肾上腺静脉 (left drain into left renal vein) • Right testicular or ovarian v右睾丸（卵巢）静脉. (left drain into left renal vein) • Hepatic veins 肝静脉: right, left and intermediate

45. Relations of inferior vena cava • Anteriorly (cranially to caudally) • Liver • Head of pancreas • Horizontal part of duodenum • Right testicular (or ovarian) a. • Radix of mesentery • Posteriorly • Right crus of diaphragm • Upper four lumber vertebrae • Left sympathetic trunk • Parietal branches of abdominal aorta • On its right • Psoas major • Right kidney • Right suprarenal gland • On its left • Abdominal aorta

46. Hepatic portal vein 肝门静脉 General features • Formed behind the neck of pancreas by the union of superior mesenteric vein and splenic vein • Ascends upwards and to the right, posterior to the first part of duodenum and then enters the lesser omentum to the porta hepatis, where it divides into right and left branches • There are no functioning valves in hepatic portal system • Drains blood from gastrointestinal tract from the lower end of oesophagus to the upper end of anal canal, pancreas, gall bladder, bile ducts and spleen

47. Variation and anomalies of hepatic portal vein

48. Tributaries of hepatic portal vein 1. Superior mesenteric v. 肠系膜上静脉 2. Inferior mesenteric v. 肠系膜下静脉 3. Splenic v. 脾静脉 4. Left gastric v. 胃左静脉 5. Right gastric v.胃右静脉 6. Cystic v. 胆囊静脉 7. Paraumbilical v. 附脐静脉

49. Portal-systemic anastomoses 1. At the lower end of the oesophagus Hepatic portal vein → left gastric vein → esophageal venous plexus → esophageal vein → azygos vein → superiorvena cava 2. At rectal venous plexus Hepatic portal vein → splenic vein → inferior mesenteric vein → superior rectal vein → rectal venous plexus → inferior rectal and anal veins → internal iliac vein → inferior vena cava 3. At periumbilical venous plexus Hepatic portal vein→paraumbilical vein→periumbilical venous plexus→ • thoracoepigastric and superior epigastric vein → superiorvena cava • superficial epigastric and inferior epigastric veins → inferior vena cava

50. 4. Portal-retroperitoneal anastomosis Between the retroperitoneal branches of the colic veins and the lumbar veins, pancreaticoduodenal veins with the renal veins and the subcapsular veins of the liver with the phrenic veins twigs of colic veins (portal) anastomosing with systemic retroperitoneal veins