Anatomy 2012-10-30

I. Possible Anastomoses in Portal Circulation

II. Topography of Duodenum and Pancreas

III. Lymphatic Drainage of GI tract

<I. Possible Anastomoses in Portal Circulation>

0. Portal vein: drains from unpaired visceral organs

• Splenic v.
• Superior Mesenteric v. ; portal v. made from union of splenic v. and sup. mes. v.
• Right and left gastric v. = Coronary v.
• Inferior mesenteric v.; joins to the union or SV / SMV

1. Anastomoses in Portal Circulation

1. Cardiac anastomoses: (mortal rate: 50%)
   Sup. Vena Cava ← Azygos, hemiazygos vv. ← Esophageal branch ← Cardiac varices ↔ Right and left gastric v. ↔ Portal vein (normal: Cardiac → Gastric → Portal) = in portal hypertension (i.e. hepatic cirrhosis) – protruding submucosal vessels -> swallowing can hurt venous plexus
2. Hemorrhoidal anastomoses:
   Anorectal varices: dilation of collateral submucousal vessels due to backflow in the veins; by portal hypertension
   Inf. Vena Cava ← Common iliac v. ← Internal iliac v. ← Middle and inferior rectal v. ← Rectal / Hemorrhoidal varices ← Superior rectal v. ← Inferior mesenteric v. ← Portal v.
   (normal: lower ⅔ not drained to portal v.; Sup. rectal v. → Inf. mesenteric v. → Portal)
3. Periumbilical anastomoses: veins can open around lig. teres hepatis; caused by backflow from portal vein = results in “caput medusae”
   Sup. Vena Cava ← Brachiocephalic / Subclavian ← Thoracoepigastric vv. ← Umbilicus, connected with Portal v. via Periumbilical vv. → Superficial epigastric v. → Femoral v. → External iliac v. → Common iliac v. → Inf. Vena Cava
4. Retroperitoneal anastomoses:
   *ascending lumbar vv.: (azygos, hemi- v.) body wall, but drains to Superior Vena Cava
   Portal vein drainage: Kidney, Right colic v. (ascending colon) → Sup. mesenteric v., Left colic v. (descending colon) → Inf. mesenteric v.
   Inferior Vena Cava: lumbar veins

<II. Topography of Duodenum, Pancreas>

0. Dissections

1. Vater’s papilla (ampulla of Vater) / Major duodenal papilla : point of insertion for common bile duct, major pancreatic duct into duodenum; sphincter
2. Minor duodenal papilla / accessory bile duct : above Vater’s papilla
3. Ileocecal junction : mouth = ileocecal valve; prevents reflux

1. Topography of Duodenum

• Superior Horizontal Part of Duodenum (L1)
  • left: stomach
  • right: continues to descending part
  • above: gall bladder *color
  • below: head of pancreas
  • posterior: portal vein, common bile duct, gastroduodenal lig.
• Descending Part; retroperitoneal
  • left: head of pancreas + thru. the head, common bile duct + anastomoses of sup. et inf. pancreaticoduodenal a. et v.
  • right: X
  • above: superior horizontal part
  • below: inferior horizontal part; completely retroperitoneal
  • anterior: transverse mesocolon
  • posterior: hylum of right kidney
• Inferior Horizontal Part (L3)
  • left: duodenojejunal flexure (ascending part) (L2)
  • right: descending part
  • above: head of pancreas
  • below: X
  • anterior: superior mesenteric a. et v.
  • posterior: inferior vena cava, abdominal aorta *fork

2. Pancreas
= surrounded by duodenum. retroperitoneal; Head: deepest (L1~L3); Body: L1; Tail: T12

1. Head: surrounded by different parts of duodenum
   1. anterior: transverse mesocolon, duodenum, ducts, anastomoses (pancreaticoduodenal)
2. Body: obliquely rises
   1. posterior: inferior vena cava, abdominal aorta, crura of diaphragm
      obliquely crosses the left kidney
   2. anterior: lesser sac (through which, stomach)
3. Tail: reaches spleen (pancreatic surface) *protrusion of pancreas to liver
4. Vessels:
   1. Aorta and Inferior Vena Cava
   2. Superior Mesenteric a. et v. under pancreas, surrounded by the head (ucinate process)
   3. SMV, Splenic v. → Portal v.: starts behind the pancreas, at the transition of head and body
   4. Splenic a. et v.: behind pancreas

<III. Lymphatic Drainage of GI tract>

1. Pyloric Lymph Nodes → Hepatic L.N.N
2. Left Gastric Lymph Nodes → Left Supraclavicular L.N.
   (Virchoff; first sight of GI cancer = enlarged lymph nodes)
3. Pancreaticolineal Lymph Nodes
4. Right Gastric Lymph Nodes *Cysterna Chyli: behind pyrolus; but no drainage

Lymphatic Drainage of Intestine = similar to blood supply; mesenterial lymph nodes

• Sup. Mesenteric v.: Jejunum, ileum, cecum → Intestinal Trunk
• Inf. Mesenteric v. → Lumbar Trunk