GIT blood supply

About the arterial supply and venous drainage of Abdomen.

1. Blood Supply of GIT Dr. Komal Parmar Total Number of Slides: 45

2. Aims and Objectives Understanding the three dimensional topography of vascular system inside the abdominopelvic cavity. Detailed description of the blood supply of gastrointestinal tract. Clinical and pathological correlation. 2

3. Blood Supply of Oropharynx 3

4. Blood Supply of Oesophagus 4

5. Entry into the A bdominal C avity T8: Caval Opening IVC Right Phrenic Nerve T10: Esophageal Hiatus Esophagus Vagal Trunks Esophageal Vessels T12: Aortic Hiatus Aorta Thoracic Duct Azygous Vein 5 Thoracoabdominal Interface

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7. General Arrangement of Abdominopelvic Vascular Supply: Arterial Supply 7

8. Venous System 8

9. 9 Portal Venous System

10. Arterial Supply 10

11. Abdominal Aorta Begins at Aortic hiatus of Diaphragm: T12 Bifurcates into two common iliac arteries at L4/5 intervertebral disc. Mean diameter= 19-21mm in males 16-18mm in females Relations: Anterior = Coeliac trunk, Autonomic nerve plexuses, lymphatics , pancreas, 3 rd part of duodenum, root of mesentry Posterior : Vertebrae, I/V disc and ligaments, Lumbar Arteries Right : Thoracic Duct, Azygous Vein, Right Crus of Diaphragm, IVC, Right Coeliac Ganglion. Left: Left Crus of Diaphragm, Left Coeliac Ganglion, 4 th part of Duodenum, Left Sympathetic Trunk, Inferior mesenteric Vein. 11

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13. Branches of Abdominal Aorta Anterior group (unpaired) Coeliac Trunk Superior Mesenteric A Inferior Mesenteric A Lateral Group Middle Suprarenal A Renal A (R>L) Gonadal A Dorsal Group Inferior Phrenic A Lumbar A (4) (*** Artery of Adamkewicz ) Median Sacral A (1) 13

14. Coeliac Trunk T12 1-3 cm long. Trifucration and ramification Related to respective crus of diaphragm and coeliac ganglion on each side. 14

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16. Splenic Artery Tortous . 8-32cm long. Largest branch of the coeliac trunk. Runs along the upper border of pancreas. Branches Pancreatic Short Gastric Left Gastroepiploic 16

17. Common Hepatic Artery 17

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19. Superior Mesenteric Artery Originates 1 cm below the Coeliac trunk Lower border of L1, Transpyloric plane. Posterior relations: uncinate process of Pancreas, 3 rd part of Duodenum, left renal vein, IVC, right ureter, right psoas . Anterior Relations: Splenic vein and Body of Pancreas. ***Marginal Artery 19

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21. Inferior Mesenteric Artery Arises behind the inferior border of 3 rd part of Duodenum. 3-4 cm above the aortic bifurcation 21

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23. Rectal Arteries 23

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26. 26 Veins

27. Mesenteric Veins Inferior Mesenteric Begins as Superior Rectal Vein. Receives Sigmoidal Veins and Left Colic Veins Drains into Splenic Vein eventually. Superior Mesenteric Tributaries Right Gastroepiploic V Inferior Pancreaticoduodenal V Middle colic V Right Colic V Ileocolic V Ileal V Jejunal V Drains into: Portal Vein 27

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29. Splenic Vein Tributaries Short Gastric Left Gastroepiploic Pancreatic Veins Inferior Mesenteric 29

30. Portal Venous Circulation 30

31. Portal Vein Formed behind the neck of Pancreas at the level of L1/2 intervertebral disc. Superior mesenteric Vein + Splenic vein 8cm Ascends behind the 1 st part of Duodenum, CBD and gastroduodenal artery. Enters the right border of Lesser Omentum and reaches the right end of Porta hepatis behind CBD and Hepatic Artery. Divides into R and L branches which accompany the corresponding Hepatic Artery. Tributaries: Left gastric and Posterior Superior P ancreaticoduodenal . Cystic veins, P ara Umbilical veins. 31

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34. 34 Hepatic Lobule

35. Hepatic Veins The hepatic veins are divided into upper and lower groups The upper three drain the central veins from the right, middle, and left regions of the liver and are larger than the lower group of veins . The lower group of from six to twenty smaller hepatic veins come from the  right lobe  and the  caudate lobe , are in contact with the hepatic tissue, and are valveless . All the veins empty into the inferior vena cava at the back of the liver . 35 Hepatic veins draining into IVC

36. Inferior Vena Cava 36

37. IVC F ormed by the junction of the common iliac veins anterior to the 5 th lumbar vertebral body. Tributaries Lumbar veins Right Gonadal vein Renal veins (L>R) Right Suprarenal vein Inferior phrenic veins Hepatic Veins 37

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39. Portosystemic Shunt : Occur at the sites of Porto- Caval Anastamoses 39 Clinical Correlates

40. Aortic Aneurysm 40

41. Gastrointertinal Bleeding 41

42. Mesenteric I shchemia 42

43. Intestinal Resection and Anastomoses 43

44. Conclusions Arterial system and Venous system do not follow an exactly parallel system. Importance of Portal Venous system and Liver as the focal site of metabolism. Correlation of anatomical intricacies with the Clinical requirements. Tip for consolidating the information: Look at the figures and approach it conceptually. 44

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