Has a projection from inferior part-the incanate process-that extends to the left
Neck:
Overlies superior mesenteric vessels
Is adjacent to pylorus of stomach
Superior mesenteric vein (SMV) joins splenic vein to form portal vein posterior to neck
Body
Crosses body of L2 and aorta
Lies in floor of omental bursa
Related anteriorly to the stomach
Is in contact posteriorly with aorta, superior mesenteric artery (SMA), left suprarenal gland, left kidney, and related vessels
Tail
Lies anterior to the left kidney
Related to hilum of spleen and left colic flexure
Main pancreatic duct
Begins in the tail and runs towards the head
Turns inferiorly to join common bile duct to form hepatopancreatic ampulla (of Vater)
Opens on major duodenal papilla in descending portion of duodenum
Surrounded by the sphincter of Oddi-smooth muscle
Accessory pancreatic duct
Opens at summit of minor duodenal papilla
Can connect with main pancreatic duct (60% of time)
Can be main duct for pancreatic secretions
Variation as a result of type of fusion or lack of fusion of dorsal and ventral pancreatic ducts during embryonic development
Vascular supply (Section 4-6: Abdomen-Visceral Vasculature)
Arteries
Mainly from branches of splenic artery
Also from gastroduodenal, superior mesenteric, superior, and inferior pancreaticoduodenal arteries
Veins
Mainly drain to splenic vein
Also drain to SMV and then portal vein
Lymph
Follow blood vessels
Mainly drain into the pancreaticosplenic nodes along splenic artery
Nervous supply (Section 4-7: Abdomen-Innervation)
From the vagus
From thoracic splanchnic nerves
Fibers from celiac and superior mesenteric plexuses pass along arteriespage 150
page 151Spleen
Largest lymphatic organ, very vascular
Located in left upper quadrant (LUQ)
Related posteriorly with ribs 9 to 11 (separated by diaphragm)
Covered by peritoneum except at the hilum
Surrounded by a thin capsule of fibroelastic connective tissue
Relations:
Anterior: stomach (gastrosplenic ligament)
Posterior: diaphragm
Inferior: splenic flexure of colon
Medial: left kidney (splenorenal ligament)
Tail of pancreas extends to hilum
Ligamentous attachments
Gastrosplenic ligament to greater curvature of stomach
Splenorenal ligament to left kidney
Both ligaments attach to hilum
Spleen sits on phrenicocolic ligament (sustentaculum lienis)
Vascular supply (Section 4-6: Abdomen-Visceral Vasculature)
Artery: splenic artery
Twisted course from origin at celiac trunk
Divides into five or more branches that enter at the hilum
Lack of anastomoses between branches results in two to three vascular segments with avascular planes in between.
Vein: splenic vein
Formed from several tributaries at the hilum
Runs to the right behind body and tail of pancreas
Joins the SMV to form the portal vein
Lymph: drains to the pancreaticosplenic nodes
Nervous supply (Section 4-7: Abdomen-Innervation)
Derived from the celiac plexus
Travels along branches of splenic artery
Vasomotor function