C4: Biliary System Flashcards
The biliary tree beings at what level
Level of the lobule at the bile canaliculi
Microscopic canaliculi anastomoses to form what
Lobular bile ducts
Where do the R and L. Hepatic ducts join to form the CHD
Porta hepatis
List the relationship of the CHD to the PV and HA
PV: anterior
HA: anterior and lateral
Where does the CHD travel
In the free edge of the lesser omentum
What determines the length of the CBD
The insertion point of the CBD
What s the relationship of the CBD to the MPV
Anterior and lateral
Norm value for the CBD
Up to 4 mm…. varies w/ age and surgery
How does the diameter of the CBD change w/ age
Add 1mm for every decade of life after 50 yrs
Norm value for CBD post cholecystectomy
Up to 10 mm
The CBD travels through which ligament
Hepatoduodenal ligament (part of lesser omentum)
What’s the relationship of the HA and the CBD to the PV
HA: anterior and left
CBD: anterior and right
What are the 4 segments of the CBD related to the duodenum
1st part (supraduodenal) 2nd part (retroduodenal) 3rd part (infraduodenal) 4th part (intraduodenal)
Describe the 4th part (intraduodenal) of the CBD
- enters 2nd part of duodenum and inserts into ampulla of vater
- narrowest part of extrahepatic biliary tract (most likely place for stone to lodge)
What regulates the flow of bile
Sphincter of Oddi
Where does the cystic duct join the CHD
Just above the duodenum
Where does the cystic duct arise
Superior aspect of the neck of the GB
Norm value of cystic duct diameter and length
3mm diameter
4cm length
Where are the spiral valves of heisted located
The cystic duct
Are the spinal valves of Heister real valves? What is there function
- no, they’re mucosal folds
- prevent duct from over distending or collapsing…. doesn’t control flow.
- for structural support
Where is the GB located
-posterior inferior surface of the R lobe of liver in the GB fossa
Where is the Gb located compared to the MLF
Posterior and inferior
Which part of the GB is fixed? Which is mobile
Neck is fixed
Body is mobile
What is the most reliable landmarks for the GB
MLF
what is a norm value of the intrahepatic ducts
< or = 2 mm in diameter
What does in indicate when yo see too many tubes
Intrahepatic duct dilation
What is the norm size of the GB
8-9 cm in length
3-5 cm in diameter
What is the most dependent part of the GB in supine and LLD
Supine: neck
LLD: fundus
What’s another term for the body of the GB
Corpus
Which are of the GB contain the spiral folds
Neck
Norm value for GB wall measurement in fasting state
<3 mm in thickness
What are the 4 layers of the GB wall. Describe each
Mucosa:
Inner epithelial lining
* FUNCTION to concentrate bile
Muscularis:
Muscle layer
Subserous layer:
C-tissue
Serous:
Outer layer in contact w/ peritoneum
What are the Rokitansky-Aschoff sinuses
Multiple folds along the inner lining of the GB
Do we usually see the RA sinuses
No, only w/ pathology
How much bile does the GB hold
40-70 ml
How is bile concentrated?
By secreting mucous and absorption get water
What controls bile secretion
The release of CCK (cholystokinin) which is produced by the duodenum
What does CCK stimulate
The Gb to contract and the sphincter of Oddi to relax
What does the sphincter of Oddi control and what does it prevent
-controls flow of bile into the duodenum and prevents reflux of GI fluids in to the biliary system
What happens to the Gb and the sphincter of Oddi when the sm intestine is empty
Sphincter closes and bile backs up into the GB
What amount of bile salts are produced daily
1 gram
What is a precursor to bile salt
Cholesterol
What is jaundice. What is another term for it
Yellowish tint in body tissue due to large quantities of bilirubin (will cause ascites)
Where does the GB get its blood supply (arterial and venous)
Arterial: cystic artery
Venous: cystic vein which drains into the portal veins
What is a junctional fold
Fold that occurs @ the junction of the body and infundibulum (neck) of the GB
What is Hartman’s pouch
An outpouching in the area of the GB neck
What is a Phrygian cap
When the GB is partially folded onto itself in the area of the fundus ad body
What are some other GB variants
- too mobile
- ectopic
- low lying
- embedded in liver
How does the GB appear on US
Anechoic
Well defined thank, echogenic walls
SAG: pear shape
TRX: anechoic circle
In what position should you scan the GB in
Supine, decubitus to assess for mobility
What should you assess when scanning the GB
Size, shape, wall thickness, content, area around the GB
How can you minimize artifacts in the GB
Come to the R and angle back towards the GB
How should you measure the CBD
In the region of the porta hepatis, measure inner to inner @ the widest portion
Do you measure the CBD where it crosses the HA
No b/c the HA will compress the CBD
What does the WBC lab test check for
What could an increased WBC lab value indicate in terms of the GB
- measures rxn of body to infection
- acute and/or chronic cholecystitis or injury to bile duct (depending on the cause)
What is a HIDA scan
- nuch med test
- evaluations function of the GB
What is a ERCP test
-ampulla of vater is cannulized and contrast material is injectors to assess biliary system
Norm value for CHD
4mm