lecture 3 liver portal system Flashcards
dorsal mesogastrium
pancreas develops; liver develops in ventral mesogastrium
revision slide of embryo at 5th week
slide 2; left lateral sagittal view: bare area means in direct contact with inferior surface of diaphragm (not enclosed in visceral peritoneum of liver)
transverse view of mesenteries in relation to stomach, liver, spleen from top
posterior peritoneum → splenorenal ligament → spleen → gastrosplenic ligament → stomach (lesser curvature) → lesser omentum (gastrohepatic and hepatoduodenal ligaments) → liver → falciform ligament → anterior peritoneum
where does liver develop
ventral foregut mesentery
what does the bare area of the liver have contact with
right dome of diaphragm - no visceral peritoneum
surface anatomy of liver
deep to ribs 7-11, mostly under cover of ribs, extends across right and left hypochrondrium and epigastrium; palpate on right hypochondriac region but can’t palpate normally as under costal margin (epigastrium under rectus abdominis)
what does the falciform ligament separate
2 anatomical lobes of liver
what protrudes out of falciform ligament anteriorly and what is it a remnant of
ligamentum teres, obliterated fibrous remnant of the left umbilical vein
what divides liver into 2 main lobes and 2 accessory lobes
peritoneal reflections
what ligament is present superiorly on left lobe
left triangular ligament
what ligament is present superiorly on right lobe
coronary ligament
4 lobes of liver
right, left, quadrate (anterior, right of fissure for ligamentum teres), caudate (posterior, right of fissure for ligamentum teres); both quadrate and caudate are accessory lobes on right side of liver
3 sections of gall bladder
fundus, body, neck
what divides functional (vascular) lobes of liver
imaginary line between inferior vena cava and gall bladder (left hepatic artery and right hepatic artery supply just 1 lobe separately)
quadrate and caudate
caudate gets blood supply from both arteries, quadrate only receives from left hepatic artery
lobule structure
portal triad (hepatic artery branch, portal vein branch, bile ducts), sinusoids, central veins to hepatic veins, 1/3rd = 1/2 acinus
liver segments - can remove one without damaging others
I-VIII, each with own blood, venous supply, inferior vena cava, left, intermediate and right hepatic veins, right and left branches of hepatic artery, portal triad, gallbladder
what mark separation of liver into functional right and left lobes
gall bladder, inferior vena cava
what marks out minor parts of functional left lobe
grooves for foetal veins (from ligamentum teres) into quadrate and caudate lobes
what separates quadrate and caudate lobes
porta of liver (carries several structures)
what does the porta carry
hepatic artery, portal vein, common bile duct, lymphatics
anatomical relations of liver
slide 14
what covers liver
costal margin except in upper gastrium
shape of diahphragmatic surface
convex
what is complex visceral surface in contact with
stomach, duodenum, right kidney, colon
visceral surface relations of liver
slide 16; at corners where peritoneum folds over, forms triangular ligament; coronary ligament anterior
arterial blood supply of liver
left gastric artery, coeliac artery, splenic artery, common hepatic artery, cystic artery (right and left branches, gall bladder), anterior and posterior superior pancreaticoduodenal arteries
what do superior pancreaticoduodenal arteries anastomose with
inferior pancreaticoduodenal arteries from superior mesenteric artery
revision slide: portal venous system
portal vein formed from mesenteric arteries, splenic vein, inferior mesenteric vein (splenic flexure; left colon - descending, rectum), superior mesenteric vein (ascending colon, caecum, transverse colon); most oxygen from venous system (portal vein)
where is hepatic artery derived from
coeliac axis
how does venous blood from liver drain directly into inferior vena cava
via 3 short hepatic veins - difficult to see
4 sites of portal-systemic anastomoses (systemic then portal)
oesophageal vein and left gastric veins; inferior rectal vein and superior rectal vein both important); epigastric vein and paraumbilical vein; retroperitoneal vein and visceral vein (less important)
if portal pressure increases, blood diverted into systemic veins - if enlarge are liable to rupture
slide 20
what may happen to portal-systemic anastomoses if portal flow through liver is obstucted in liver disease
dilate
what anasomoses are haemorrhages common
oesophageal vein and left gastric veins; inferior rectal vein and superior rectal vein
what do pancreatic duct and bile duct have and join to form
each have separate sphincters and join to form hepatopancreatic ampulla of Vater
what guards the ampulla of Vater
sphincter of Oddi
what can obstruct ducts at sphincter of Oddi
neoplasms of head of pancreas - blocks pancreatic and bile duct exits so bile accumulates - jaundice
pancreas may have accessory duct
proximal to major papilla
what do left and right hepatic ducts form
common hepatic duct
what joins the common hepatic duct and what does this form
cystic duct from gall bladder, forming common bile duct
what does the common bile duct pass behind and where does it enter and join
passes behind 1st part of duodenum and head of pancreas to enter 2nd part of duodenum at major papila, joining major pancreatic duct
relations of gall bladder with first part of duodenum
between gall badder and duodenum is the site of cholecystoenteric fistula, where large gall stones may enter directly into duodenum
fundus of gall bladder
palpate
what is the largest lymphoid organ in the body
spleen (fist-sized) - not part of GI but in abdomen
what suspends the spleen
gastro-splenic and lieno-renal ligaments in dorsal foregut mesentery
where does the spleen lie
posteriorly on left side under ribs 9-11
what does spleen have relations with
stomach, left kidney, left (splenic) flexure of colon, tail of pancreas
what does traumatic rupture of spleen cause
severe haemorrhage (e.g. if ribs break) - can’t repair so removed
surface anatomy of spleen
left hypochondrion, under ribs 9-11 (left lateral view)
hilar surface of spleen
gastrosplenic ligament, superior gastric area of hilum, splenorenal ligament inferior renal area of hilum, anterior colic area
what are both splenic ligaments
gastrosplenic, splenorenal
what are both splenic ligaments part of
greater ommentum
function of splenic ligaments
blood vessels to spleen enter through them
