Gastrointestinal System IV Liver, Pancreas And Spleen Flashcards
Where is the liver?
Right hypochondrium and epigastric region
What can cause liver trauma?
Liver trauma can be caused by: Fractures of lower ribs.
Penetrating wounds of the thorax or upper abdomen. Blunt trauma. All can be associated with severe hemorrhage
What is liver cirrhosis?
Cirrhosis of liver – progressive destruction of hepatocytes [replaced by fibrous tissue], which makes the liver firm, impedes blood circulation [most frequent cause of portal hypertension]
How is a percutaneous liver biopsy performed?
Percutaneous Liver biopsy : Patient asked to hold breath in full expiration to prevent damage to pleura / lung. Needle is inserted through the 9th / 10th right intercostal space in the mid axillary line.
What are the two surfaces of the liver?
Diaphragmatic: anterior, superior, posterior
Visceral surface: inferior and covered with visceral peritoneum (except the fossa for gallbladder+ porta hepatis)
What us the subphrenic space?
Between diaphragm and liver
What is the hepatorenal recess?
[between right kidney & liver] is the gravity dependent part of
the peritoneal cavity in supine position
What is the importance of liver lobes?
Caudate & quadrate lobes – functionally belong to left lobe [left branches of the hepatic artery, portal vein & bile duct]
Right & left lobes; Right lobe larger
with caudate & quadrate lobes
Porta hepatis – structures enter / leave the liver (except hepatic veins)
What are the segments of the liver?
liver is divided into 8 segments based on the main branches of right & left hepatic arteries, portal vein & hepatic ducts [hepatic veins → intersegmental]
Branches of the right & left hepatic arteries, ducts and
portal vein do not communicate significantly. [hepatic
lobectomy / segmentectomy can be performed]
What is the anatomical importance of lobes in the liver?
- Anatomically the liver can be divided into four lobes : right ,left, caudate and quadrate . In this classification the quadrate and caudate lobes are considered part of the right liver.
- Functionally it can be divided into independent right and left livers i.e. portal lobes. This functional division is produced by the sagittal plane passing through the gall bladder fossa and the fossa of the IVC on the visceral surface of the liver and an imaginary line over the diaphragmatic surface that runs from the surface of the gall bladder to the IVC. The left liver now includes anatomic quadrate and caudate lobes.
This functional division results in the liver having a slightly larger right lobe. These “portal lobes” will have its own blood supply from the hepatic artery, portal veins, its own venous (hepatic veins) and biliary drainage.
• The portal lobes of the liver are further divided into 8 segments. The segmentation is based on the principal branches of the right and left hepatic arteries, hepatic portal veins and hepatic ducts . Each segment is supplied by the corresponding branch of the right or left hepatic artery, portal vein and drained by a branch of the left or right hepatic duct
What is the falciform ligament?
Falciform – liver is attached to the anterior abdominal wall. Posterior
free margin is the ligamentum teres → obliterated umbilical vein
What is the bare area?
Bare area – triangular area devoid of peritoneal covering, related to the diaphragm
What is the ligamentum venosum a remnant of?
Ductus venosus
What is the lesser omentum?
Lesser omentum – connected to stomach
[hepatogastric] & duodenum [hepatoduodenal part]
Right free margin of the lesser omentun contains portal vein, proper hepatic artery & bile duct
What is the pringle maneuver?
Pringle maneuver is clamping hepatoduodenal ligament to
prevent bleeding from proper hepatic artery
What is the blood supply of the liver?
Arterial supply – hepatic artery
Veins – hepatic & portal
Hepatic artery [30%] & portal vein [70%] to the liver; hepatic veins open in to IVC
Liver produces large amount of lymph → mainly to celiac nodes
Summarize structure of the gall bladder
Receives bile from the liver (stores & concentrates it)
Pear shaped, in the fossa [inferior surface of liver]
Parts – fundus [projects beyond the inferior
margin of liver→ located at the tip of the SOM.1aii.BPM2.1.DM.1.ANAT.DG.4449 right 9th costal cartilage mid-clavicular line], Body, neck→leads to cystic duct
What is the biliary apparatus?
Right & left hepatic ducts join to form the common hepatic duct; joined by the cystic duct to form the [common] bile duct
BD passes posterior to the I part of duodenum, joins the
pancreatic duct to open into the major duodenal papilla
Can gall stones be asymptomatic?
Gall stones may be asymptomatic [common in fat, fertile, female of forty]; can produce colic or acute cholecystitis
What is biliary colic?
Biliary colic – usually caused by spasm of the smooth muscle of the gall bladder in an attempt to expel the gall stones
What is acute cholecystitis?
Acute cholecystits – pain in the right upper quadrant→may cause subdiaphragmatic parietal peritoneum irritation, which is supplied by the phrenic nerve [referred pain → right shoulder]
What is the significabce of an obstruction of biliary tree by gall stones?
Obstruction of biliary tree by gall stone or compression by pancreatic growth→obstructive jaundice. Impaction of stone in the ampulla can cause passage of infecte bile into the pancreatic duct leading to pancreatitis
What is an ERCP?
ERCP (endoscopic retrograde cholangiopancreatography) is a diagnostic procedure used to evaluate the biliary and pancreatic ducts. A tube is passed via the esophagus stomach 2nd part of the duodenum. Dye is injected into the major papilla under fluoroscopy
Where is the spleen located?
Spleen mainly in the left hypochondrium, surrounded by visceral peritoneum
Describe splenic rupture
though well protected it is the most frequently injured organ in the abdomen, bleeds profusely when ruptured → intra- peritoneal hemorrhage & shock. If repair is difficult→Splenectomy
What is splenomegaly?
diseases affecting the reticulo- endothelial system, portal hypertension may cause splenic enlargement
Describe the function of portal vein
Collects venous blood with products of digestion from the abdominal part of GIT + gallbladder, spleen & pancreas
Passes through the lesser omentum, enters the liver through porta hepatis, divides into right & left and then segmental branches→ends in venous sinusoids of liver
Describe the formation if the portal vein
Formation – behind the neck of pancreas; joining of splenic vein & superior mesenteric vein
Describe portal systemic [porto-caval] anastomoses
Portal vein tributaries communicate with caval tributaries
- Lower end of the esophagus
Esophageal tributaries of the left gastric vein with esophageal tributaries of azygos & hemiazygos veins [Esophageal varices → Hematemesis]
- Lower end of the anal canal
Superior rectal vein [drains into inferior mesenteric vein] with Inferior & middle rectal veins (→internal iliac vein). Varicosity leads to hemorrhoids [piles]
- Umbilicus [Anterior abdominal wall]
Veins along the ligamentum teres – para-umbilical veins with tributaries of the superior and inferior epigastric veins specifically the superficial epigastric veins. These dilated tortuous superficial epigastric veins radiating from the umbilicus are called Caput Medusa
- Retro-peritoneal organs: Veins of colon, duodenum, pancreas, spleen etc. with Renal, lumbar, azygos veins etc.→Dilated veins around the posterior abdominal wal
- Bare area of the Liver: Venous sinusoids of liver with Diaphragmatic veins [intercostal & phrenic]
Describe portal hypotension
Any pathology which obstructs the hepatic portal vein increases pressure in this vein and its tributaries. A common method for reducing portal hypertension is to divert blood from the portal venous system to the systemic venous system by creating a shunt (communication) between the portal vein and the inferior vena cava.
How is the pancreas special?
Mixed gland – exocrine & endocrine; with age exocrine part & connective tissue decline – progressive thinning atrophy
Describe the structure of the pancreas
Extends across [12 - 15cm] posterior abdominal wall [retroperitoneal] from the duodenum on the right to spleen on the left. Mostly posterior to the stomach
Parts – head with uncinate process, neck, body & tail [mobile within the splenorenal ligament]
Where is the minor pancreatic duct located?
Minor pancreatic duct – opens above the major duodenal papilla, usually communicates with the major duct
What is the major pancreatic duct?
passes from the tail towards the head; joins the bile duct to form hepatopancreatic ampulla, which enters the major
duodenal papilla [II part of duodenum]
Describe the arteries of the pancreas
- Anterior & posterior superior pancreaticoduodenal arteries – branch of gastroduodenal artery (Celiac artery)
- Anterior & posterior inferior pancreatic duodenal artery – branch of SMA
- Pancreatic branches – numerous from the splenic arter
Describe the veinous drainage of the pancreas
To portal vein. Head & neck to superior mesenteric vein ; body & tail – to splenic vein
Describe pancreatic lymph drainage
The pancreatic lymph vessels follow the arteries and will therefore drain into :
- Celiac nodes
- Superior mesenteric nodes
Describe the clinical correkation of pancreatic rupture
Rupture of the pancreas – may result from sudden, forceful compression of the abdomen
Describe the pancreatic cancer clinical signuficance
Pancreatic cancer – of the head may cause obstructive jaundice →retention of bile pigments, enlargement of the gall bladder. Growth may compress the portal vein leading to portal hypertension
