C3: Liver Flashcards
which aspect of the liver is in contact w/ the diaphragm
superior, anterior, posterior
the liver occupies which regions of the body
R hypochondrium
epigastric
L hypochondrium (sometimes)
which surface of the liver is indented by the R kidney
posterior IVC runs through posterior aspect too)
what can cause displacement of the liver caudally
tumors
cirrhosis
subphrenic abscesses
what can cause displacement of the liver cranially
abdo tumor
ascites
excessive dilation of the colon
how much larger is the R lobe than the L
2-3 X larger
whats the norm length measurement of the liver? where would you measure it
= 15.5 cm
-@ midclavicuar line: from diaphragm to inferior edge (where you get kidney coming in)
whats the norm AP measurement of the liver? where would you measure it
- 1 cm
- @ midpoint of longitudinal measurement
what is a norm caudate/RT lobe ratio
where would you take the ratio
<0.65
-subcostal in true trans plane
how can you tell if the liver is enlarged
-if the R lobe extends below the lower pole of the R kid (Reidels lobe is the exception)
how can you tell if the liver is enlarged or if its a reidels lobe
if a liver appears to have no pathology then its a reidels…. if there is pathology then the liver is likely enlarged
what is a reidels lobe
tongue like extension of the R lobe (inferior tip).
common in slim females
how does the anatomical method divide the liver
what landmarks does it use to divide
-into 4 lobes based on external markings (see page 3 for image)
lobes are: quadrate, caudate, R and L
- falciform lig divides the R and L lobes anteriorly
- caudate lies b/w the IVC, portal vein and Lig venosum
- quadrate divided by the porta hepatis, GB fossa and Lig teres
how does the functional method divide the liver
what landmarks does it use to divide
- into 3 lobes and 4 segments based on blood supply and billiard drainage…. uses lig, fissures and GB to divide
lobes: R, L and caudate
segments: R-anteior and posterior, L- medial (quadrate) and lateral
how do the portal and hepatic veins course in the liver
portals: intrasegmental
hepatics: intersegmental
what landmarks separate the L and R lobes of liver
Main lobar fissue
Middle hepatic vein
what landmarks separate the segments of the R lobe of liver
R intersegmental tissue
RHV
RPV
what landmarks separate the segments of the L lobe of liver
L intersegmental tissue
LHV
LPV
Lig Teres
which segment of liver used to be the quadrate lobe
medial L
the caudate lobe gets portal venous and hepatic arterial blood from which lobe
both
where is caudate lobe located
posterior of liver
what are the posterior, anterior and inferior landmarks for the caudate
P: IVC
A: Lig venosum
I: MPV
what is the caudate process
the part of the caudate that extends obliquely to the R and passes b/w the IVC and LPV
what is the papillary process
the caudal projection of the caudate lobe which lies along the Lig venosum and above the portal hepatis
what structure can the papillary process mimic
lymph node or panc. mass
each segment of couinauds contains which structure and is bound bounded by which structure
- each contains a portal vein @ its centre
- bounded by a hepatic vein
what structures are used to divide the liver in couinauds?
- RHV, MHV, LHV divide the liver longitudinally into 4 sections
- divided trans. by a line drawn through the R main and L main portal branches
which 2 structures are used as landmarks for the MLF
GB and IVC in TRANS
the L intersegmental fissure is divided into cranial, middle and caudal sections…. which structures run in which section
cranial: LHV
mid: LPV
caudal: Lig teres
the fissure for the Lig venosum divides which segment of the liver from the caudate?
what does this fissure contain?
L lateral
- contains ligamentum venosum (remnant of the ductus venosum)
- contains hepatogastric ligament (which makes up part of the lesser omentum w/ the hepatoduodenal Lig)
where is the GB fossa located?
posterior and inferior part of the R lobe of liver
where is the IVC fossa located
on the posterior surface of the liver b/w the caudate and bare area
whats the relationship of the CBD and HA to the PV
anterior
what is the glissons capsule
where is it the thickest
- capsule of c-tissue that surrounds the liver
- @ IVC and porta hepatis
which structure accompanies the portal vessel into the liver for a short distance
glissons capsule
what is the hepatoduodenal Lig? is it thinner than the hepatogastric Lig
a folder of lesser omentum
-yes
what structure forms the anterior boundary of the epiploic foramen
hepatoduodenal Lig
what 3 structures run through the hepatoduodenal Lig
MPV
HA
CBD
(portal triade)
where does the falciform Lig extend from and where does it attach (2 places)?
what structure of the fetus runs in this ligament
umbilicus to liver…. attaches to diaphragm and superior surface of liver
-fetal umbilical vein
where does the Lig teres extend from
what structure forms this ligament
LPV to inferior aspect of the liver
-fetal umbilical vein atrophies to become this ligament
another name for Lig teres
round ligament
describe the coronary ligaments, where are they located.
they connect the liver to which structure?
define the bare area of the liver
- connect to the posterosuperior surface of the liver to the diaphragm
- form the R &L triangular ligaments
the falciform Lig splits into which ligaments
coronary
which part of the coronary Lig is continuous w/ the falciform
upper portion
portal veins carry O2 low blood from which areas of the body to the liver
intestines, spleen, panc, GB and bowel
how can you tell youre in the porta hepatis region
the elongation of the MPV over the IVC
how does the RPV travel in the liver
posterior and inferior
which PV is more posterior, RPV or LPV
RPV
how does the LPV travel in the liver
cranially along the anterior surface of the caudate lobe, then turns anteriorly
why do the PV walls appear bright?
they have a c-tissue sheath that surrounds them (and the portal triade) to keep the triade togehter
which HV is the largest
RHV
which HV is the smallest
LHV
describe the US appearance of the liver
- homogenous w/ medium level echos
- minimally hyperechoic or isoechoic to the cortex of the R kidney
when comparing echogenicity of the liver the kidney cortex, at what level do you compare them
hortizontally at the same level
what is the functional unit of the liver?
how large is it
lobule
1-2 mm diameter w/ hexagon shape
how are hepatocytes organized in the liver
what is there function
- organized into 2 layers columns that converge towards a central hepatic vein
- 2 columns divided by the sinusoids so hepatocytes are in contact w/ sinusoid blood
-liberate substances into the blood and into the bile canaliculi
what are sinusoids
where are they located
highly permeable blood capillaries
-b/w the hepatocytes columns
how does blood flow in the sinusoids
-blood from a portal vein and hepatic vein enters at the periphery of the lobule and travels to the central hepatic vein through the sinusoids
sinusoids contain what % portal blood and what % hepatic
P: 80%
H: 20%
describe kupffer cells
where are they located
- part of the RE system
- function is to cleanse blood by carrying out phagocytosis
-scattered along sinusoids
what is the smallest division of the biliary tree
bile canaliculi
describe the bile canaliculi, where are they located?
- smallest division of the biliary tree
- b/w the 2 layers of the liver cell columns so bile in the canaliculi are always separated from sinusoid blood by a row of hepatocytes
how does bile enter the bile canaliculi
-bile is liberated by the hepatocytes into the canaliculi and it flows towards a larger bile duct at the outer edge of the liver lobule….
….those ducts converge to form larger ducts and then the R&L hepatic ducts… then the common hepatic duct which joing w/ the cystic duct to form the CBD
where is the portal triade located in reference to the liver lobules?
does the lobule have 1 or multiple portal triades?
at the periphery of the lobule
multiple
when do the central hepatic veins of each liver lobule eventually combine to form?
the HVs
what is the primary centre of metabolism
liver
what components of the liver carry out the majority of its functions
hepatocytes, kupffer cells and biliary cells
what is bilirubin
-bile pigment that is a product of RBC breakdown by kupffer cells and other RE cells
what is bile salt composed of and where is it formed
- cholesterol
- formed in hepatic cells
how much bile is produced daily
700-1200 ml
where is unconjugated/indirect bilirubin conjugated?
in the liver
how is most conjugated bilirubin secreted
feces
describe unconjugated/indirect bilirubin
- fat soluble (Eg stored in fat)
- not excreted in urine
- toxic to tissues
describe conjugated/direct bilirubin
- non toxic
- water soluble
- secreted by the liver into the bile canaliculi
what are the livers RE function
- produces RBCs in the fetus
- produce plasma proteins and antibodies
- removes antigens and old RBCs (via kupffer cells)
- recovers bile pigment
what plasma proteins and antibodies does the liver produce
- fibrinogen: helps w/ blood clotting
- albumin: prevents plasma loss from capillaries (helps control osmotic press)
- globulins: for natural and acquire immunity
what are the metabolic functions of the liver
metabolizes fat, protein and carbs
carbohydrates are referred to as what type of buffer
glucose buffer
what substance does the liver store
posions (copper, iron) ferritin a.a.s fats glycogen
how much blood can the liver store
200-400 mls
the liver forms how much of the bodies lymph fluid
1/3 to 1/2
what is an enzyme
-protein that catalyzes a chemical rxn… it accelerates and controls the rate of the rxn and remains unchanged after the catalyzation.
when might enzymes be released into the blood stream
when theres damage to tissue…. b/c of this enzyme levels reflect body function
what is ALT or SGPT
- enzyme produced by the hepatocytes
- specific indicator of hepatocelluar damage
- used w/ AST to distinguish b/w cardiac or hepatic damage
- elevated ALT means you need A Liver Transplant… SGPT has a P and T and so does hePaTocyte so its specific to the liver*
what is AST or SGOT
-enzyme found in liver, muscle and tissue w/ high metabolic rates
what is ALP or Alk phos
what do increased values indicate
enzyme in the liver, bone, intestines and placenta
-biliary obstruction
what does it mean if ALP is increased w/ a norm AST and ALT?
disease of the bile duct
what is LDH
-“likely dead heart”
- enzyme found in multiple organ systems
- used to detect MI or pulmonary infarcts
- NON specific indicator of liver damage
what is GGT
- “ginger gin and tonic”
- sensitive to the effects of alcohol in the liver
- NON specific indicator of liver damage
what is AFP
what do increased values indicate
- PROTEIN produced in fetal tissue and by the liver
- hepatocellular carcinoma and testicular carcinoma
what does a bilirubin blood test measure and what does it include
concentration of bilirubin
includes:
total bilirubin
unconjugated/indirect
conjugated/direct
what is total bilirubin
what do increased values indicate
- combines unconjugated and conjugated
- hepatocellular disease
what do increased values of unconjugated/indirect bilirubin indicate
-hepatocellular disease
what do increased values of conjugated/direct bilirubin indicate
-extrahepatic bile duct obstruction or bile duct disease
what is a prothrombin time lab test
- prothrombin is a clotting factor produced in the liver & effected by levels of Vit K
- test measures the ability to clot
what is INR
what value is norm
w/ what value should you not do a biopsy
-international normalized ratio
- ratio used in place of PT
- value of 1 is norm
- > 1.2 - liver biopsy shouldnt be done
what is PTT
when will it be prolonger
measures clotting time of blood
-in hepatic disease and anticoagulant therapy
what is a serum protein lab test
what do increased values indicate
- checks for levels of albumin in blood
- liver dysfunction
why is hepatitis testing used
used to determine if patient has been exposed to or currently has or is a carries of viral hepatitis
