Abdominal Viscera: Part II Flashcards
spleen
- lymphatic organ that filters erythrocytes and platelets from circulation
- LUQ
- most frequently ruptured organ
- peritonealized
Antioer: stomach
Posterior: diaphragm, costodiaphragmatic recess, ribs 9-11
inferior: left colic flexure
features of spleen
hilum: faces anteromedially, receives blood vessels
borders:
1. superior and anterior: notched and sharp
inferoposterior: smooth
gastrosplenic ligament
attaches stomach to spleen
splenorenal ligmament
attaches spleen to kidney and posterior body wall
phrenicocolic ligament
spleen rests inferiorly on this ligament
vasculature of spleen?
Splenic a: branch of celiac trunk: takes tortuous course through superior panceas
- travels through splenorenal ligament to hilum of spleen and divides into 4-5 end segments
Splenic v. receives IMV, and merges with SMV to form portal v.
splenomegaly
enlarged spleen due to pathology; can be palpated in LUQ below costal margin
Accessory spleens
common and are typicaly found within gastrosplenic ligament
pancreas
exocrine: secretion of pancreatic enzymes into duodenum for digestion
endocrine: secretion of pancreatic hormones into bloodstream from islets of Langerhans (glucagon and insulin) to control blood glucose
- secondarily retroperitoneal
- extends from duodenum on right to spleen on left
features/anatomy of pancreas
head: lies within concavity of duodenum
anterior: pyloric region of stomach, small intestine
posterior: LV1-2, IVC and renal vessels; bile duct
right and inferior: duodenum
uncinate process lies below
anterior: superior mesenteric vessels
neck: passes anterior to superior mesenteric vessels
anterior: transverse mesocolon, small intestine
posterior: superior mesenteric aa; formation of hepatic portal v.
body: continues from neck to tail
anterior: stomach
posterior: aorta, left suprarenal gland, left kidney, renal vessels
tail: lies within splenorenal ligament
contacts spleen in hilum
main pancreatic duct
duct of Wirsung
- begins in tail, travels through inferior portion of body and head
- merges with bile duct to form the hepatopancreatic ampulla (of Vater)
- empties into second portion of duodenum at major duodenal papilla
- sphincerters control release of bile and pancreatic enzymes
accessory pancreatic duct of Santorini
- travels through superior portion of head of pancreas
- empties into 2nd portion of duodenum at the minor duodenal papilla
blood supply to pancreas
Celiac trunk supplies splenic a, and gastroduodenal a.
splenic a: dorsal pancreatic a. pancreatic magna, artery to tail
gastroduodenal a. anterior and posterior superior pancreaticoduodenal aa.
venous drainage: to hepatic portal v.
pancreatitis
common cause of inflammation of pancreas is reflux of bile through hepatopancreatic ampulla and into the main pancreatic duct. this is commonly due to an obstructing gallstone
pancreatic cancer
can cause obstruction of the bile duct leading to gallbladder enlargement, retention of bile, and secondary jaundice (backup of bile into blood stream)
liver
functions to metabolize bile, lipids, carboyhdrates, proteins
- produces urea
- detoxification
- located in RUQ
- left lobe extends into LUQ
external features of liver
- diaphragmatic surface (anterior superior) - surface is smooth and convex
- visceral (posterior and inferior) - surface is concave
porta hepatis
fissure on central portion of visceral surface of liver
- entrance of hepatic aa, portal v, hepatic bile ducts, lymphatics, nerves
what makes up H on visceral surface of liver?
sagittal fissures to left and right of porta hepatis
right fissure: contains gallbladder anteriorly and IVC posteriorly
left fissure contains ligamentum teres hepatis anteriorly, and ligamentum venosum posteriorly
anterior to porta hepatis is quadrate lobe
posterior to porta hepatis is caudate lobe
falciform ligament
- on anterior surface of liver, dividing right and left lobe
- extends into the round ligament (ligamentum teres)
coronary ligaments
- attach liver to diaphragm
- anterior and posterior layers no apposed medially, creating bare area of liver
- laterally, anterior and posterior layers fuse to form the triangular ligaments
lesser omentum
hepatoduodenal ligament + hepatogastric ligament
- contains the portal triad: hepatic artery, common bile duct, hepatic portal vein.
omental epiploic forame (foramen of winslow)
formed by hepatoduodenal ligament
- contains the portal triad: hepatic artery, common bile duct, hepatic portal vein.
subphrenic recess
extension of greater sac between anterior surface of liver and diaphragm
- bounded deeply by anterior layer of coronary ligament
- seperated into right and left portions by falciform ligament
- ** subphrenic absess= accumulation of purulent exudate in this recess - usually on the right
- drained at 12th rib
hepatorenal recess
- most posterior portion when patient laying supine
- extension of greater sac between visceral surface of liver and kidney
- bounded deeply by posterior portion of coronary ligament
how are anatomical lobes of kidney divided?
- rt/lt lobe via falciform ligament
- quadrate lobe: subdivision of right, lies between anterior limbs of H
- caudate lobe: subdivision of rt. lies posterior to H. caudate process extends posterior to gall bladder
What does each functional lobe receive?
primary branch of hepatic artery, portal v. and drained via hepatic duct
- right lobe, left lobe (includes quadrate), caudate lobe
segmentectomy
b/c the segments of liver are all supplied by their own artery one diseased segment can be removed without affecting function of surrounding semgnets
liver lobule
- composed of 6 hepatocytes arranged around a central vein
- at periphery of liver lobule are 6 branches of portal triad (interlobular branch of hepatic portal vein, portal artery, bile duct)
- within liver lobule, blood from portal vein and hepatic artery drain through sinusoids to the central vein.
- bile produced by hepatocytes flows within the bile canaliculi towards the periphery of the liver lobule into the interlobular bile duct
bile production in liver
bile produced by hepatocytes and secreted into bile canaliculi
- bile canaliculi –> interlobular biliary ducts –> left and right hepatic ducts –> common hepatic duct
- common hepatic duct exts at porta hepatis, and merges with cystic duct to form bile duct
bile duct
made of common hepatic duct and cystic duct
- travels within free edge of hepatoduodenal ligament
hepatopancreatic ampulla
distal bile duct + main pancreatic duct
- drains into 2nd portion of duodenum
choledochal
sphincter of distal bile duct, contracts to prevent release of bile
- bile backs up into gallbladder for storage
accessory hepatic duct
normal segmental hepatic duct that joins the main biliary system outside of the liver
- these are in danger of being damaged during hepatic surgeries
proper hepatic a.
- 20% blood to liver
- travels with portal triad - at porta hepatis, divides into right and left hepatic aa.
- many variations in hepatic aa.
hepatic portal v.
- 80% blood to liver
- brings nutrients, enzymes, hormones from digestive organs
- supplies most of O2
- formed by union of splenic and SMA vv.
- divides into lt. and rt. branches at porta hepatis
venous drainage of liver?
both portal v. and hepatic a. feed into hepatic sinusoids
- hepatic sinusoids –> central vv. –> hepatic vv. (3-4) –.>IVC
lymphatic drainage of liver?
A. superficial plexus: located deep to liver capsule, drains to hepatic lymph nodes along hepatic aa.
B. Deep plexus: parallel protal triad: drain to hepatic lymph nodes –> celiac nodes
hepatomegaly
enlarged liver
- elevation in central venous pressure can be transmitted to liver, causing it to engorge with blood
- can be painful
- potential cause of “runner’s stitch”
- can be due to hepatitis or metastaic carcinomas
gallbladder
Fn: storage and concentration of bile
- located ~ 9th MCL
- completely peritonealized usually
cystic duct
attaches to neck of gallbladder, merges with common hepatic duct to form bile duct
cystohepatic triangle : “triangle of Calot”
formed by common hepatic duct, cystic duct, visceral surface of liver
vascular supply to gallbladder?
Cystic a. : usually branch of right hepatic a: travels through cystohepatic triangle
Cystic v. : empties directly into liver or portal v.
where does gallbladder pain go?
pain from glalbladder initially referred to epigastric region. however, pain will often shift to the right T8-9 dermatomes due to inflammation of surrounding parietal peritoneum
- pain from gallbladder may also refer to C3-5 dermatomes due to sensory innervation from phrenic n.
choecystectomy
surgical removal of gallbladder- cystic a. must be clamped and ligated during this surgery, structures of cystohepatic triangle must be localized and avoided.
cholelithiasis
“gallstones”
- more common in women
- can cause pain due to mechanical injury or obstruction
- often cause obstruction of hepatopancreatic ampulla - however can also obstruct the cystic, hepatic or bile ducts
- obstruction of biliary ducts = jaundice
- passage of pancreatic enzymes to duodenum = pancreatitis
cholecystitis
gallbladder inflammation. can be caused by gallstone obstruction.
- inflammation may lead to adhesion of gallbladder wall to surrounding structures
- chronic inflammation can cause ulceration of wall and cause cholecystoenteric fisture
- gallstones can then pass from gallbladder to duodenum and cause obstruction of ileocecal junction
