Pancreas And Spleen Anatomy

Front 1

Pancreas and peritonium

Back 1

Pancreas is retroperitoneal, except for the tail, which lies within the splenorenal ligament
Located on the posterior abdominal wall between duodenum and spleen

Front 2

Pancreas Location and segments

Back 2

Located on the posterior abdominal wall between duodenum and spleen
Head is within the curve of the 1st to 3rd parts of the duodenum, to the right of the midline
Uncinate process is the part of the head posterior to SMV (and SMA)
The body passes up and to the left, anterior to the splenic vein and left renal vein

Front 3

Pancreatic Ducts

Back 3

Main pancreatic duct joins bile duct, forms hepatopancreatic ampulla and opens at tip of major (greater) duodenal papilla

Accessory pancreatic duct opens at tip of minor (lesser) duodenal papilla (2 cm superior & anterior to major duodenal papilla)
Narrowest point along bile duct is opening into duodenum  obstruction by gallstone  backflow of bile into main pancreatic duct  activation of pancreatic enzymes  autodigestion (acute pancreatitis)

Front 4

Normal Fat absorption

Back 4

Lipid rich food in duodenum promotes CCK secretion into bloodstream
gallbladder contracts & sphincters around distal bile & pancreatic ducts relax
bile and pancreatic enzymes pass into duodenum

Normal absorption of fat requires
bile (via bile duct  duodenum)
pancreatic enzymes (via pancreatic ducts  duodenum)
normal intestine.

Fat malabsorption  steatorrhoea (passage of pale, bulky, malodorous stools)

Front 5

Pancreas – relationship to vessels

Back 5

Splenic artery runs a tortuous course to the spleen, superior to body of pancreas to the spleen

SMA originates from aorta, behind pancreas but then passes anterior to uncinate process
Pancreaticoduodenal arteries in the head of pancreas supply pancreas & duodenum.

Splenic vein runs posterior to tail and body and joins SMV behind neck of pancreas to form portal vein
IMV (usually) joins splenic vein behind body of pancreas

Pancreatitis may cause thrombosis of nearby veins

Front 6

Spleen Function

Back 6

Function: blood filter, reservoir for RBCs & platelets, production of lymphocytes & antibodies, removal of old RBCs

Front 7

Spleen location

Back 7

Located in left hypochondrium, posterior to midaxillary line

Related to ribs 9, 10, 11 through diaphragm; long axis of spleen is oblique and parallel to rib 10

Front 8

Spleen external features

Back 8

Soft, red, has thin fibroelastic capsule, easily ruptured especially if enlarged (eg sudden increase in intraabdominal pressure in MVA)

Front 9

Spleen Visceral Surface

Back 9

The spleen is intraperitoneal (it is almost completely invested in peritoneum)
The superior border is notched, and when the spleen is enlarged, the notch between the anterior and superior borders may be palpable

The visceral surface has a hilum (where peritoneal ligaments attach) & impressions made by stomach, colon and left kidney (gastric, colic & renal impressions); the tail of the pancreas is close to, or in contact with, the spleen at the hilum, and within the splenorenal ligament

Front 10

Spleen – Diaphragmatic surface

Back 10

Diaphragmatic surface is separated by greater sac from diaphragm

Through the diaphragm, it is related to ribs 9, 10, 11 (long axis of spleen is oblique and parallel to rib 10)

Between the diaphragm and thoracic wall, the spleen is related to the costodiaphragmatic recess of left pleural sac  a penetrating wound can lacerate spleen causing intraabdominal bleeding and a left pneumothorax.

Front 11

Spleen – surface anatomy

Back 11

Located in left hypochondrium, posterior to midaxillary line

Relationships of spleen:

Visceral surface: stomach, left colic flexure, left kidney, and in some cases, tail of pancreas

Diaphragmatic surface: diaphragm, and through the diaphragm, the left pleural cavity and ribs 9-11

Front 12

Accessory Spleen & Splenectomy

Back 12

Clinical significance for splenectomy: Patient should be assessed presurgically for the presence of an accessory spleen(s). If undetected, an accessory spleen can enlarge after a therapeutic splenectomy.