Gall Bladder Physiology Flashcards
Fuction of Gall Bladder
• The main function of the gallbladder is to_____and _____bile and deliver it into
the duodenum in response to meals
• The gallbladder bile ducts and sphincter of oddi act together to:
concentrate and store
store/regulate flow of bile
Location of Gall Bladder
• Location: Nestled in fossa beneath liver at separation of
right/left liver lobes: 7 to 10cm length
• Components of Gall Bladder
–_____: Rounded blind end; extends 1-2cm beyond liver
margin. Contains majority smooth muscle
–_____: Main storage area; contains most elastic tissue
–______: Funnel shaped, deep in fossa (Hartmann’s Pouch)
connect to cystic duct
Fundus
Corpus
Neck
• Connection of Gall Bladder
R/L hepatic ducts join to form the common bile duct (CBD) 7-11cm long; 5-10mm diameter
• Bile produced continuously by liver excretes into bile
canaliculi; 500-1000 ml daily
• Bile secretion increases with vagal stimulation; HCL,
digested proteins, fatty acids increase flow by
stimulating hormone______
secretin
- Bile secretion decreases with _____ stimulation
- Fasting state: ____bile stored in Gallbladder.
splanchnic
80%
________greatest absorptive power per unit
area of any body structure. Capacity: 30-50 ml; 300ml
when obstructed!
Gallbladder mucosa
What changes do we see in Bile composition in gall bladder storage?
Na+ and Bile acids increase
Bicarb and Cl- decresae
What do we see for motility responses of the Fasting gall bladder , between meals
Hepatic secreation pressure 25-30 mg and we see receptive relazation during gallbladder filling
the phincter of Oddi at 11-30 mmHg between meals
*see overal pressure differnce
Tonic contractions of the sphincter of oddi
(SO) create pressure gradient that directs flow into gallbladder
• Gallbladder filling:
Gallbladder emptying: Coordinated gallbladder contraction,
SO relaxation and meal intake gallbladder empties ______
contents in 30 to 40 minutes with eating; refills 60 to 90
minutes
50 to 70%
• Main stimuli to emptying of gall bladder: _________
released from duodenum in response to meals
Hormone cholecystokinin (CCK)
• SO motility: Basal contractile pressure; Response to____
Mitigating myenteric complexes
CCK;
Neurohormal control of the GB contraction and biliary secreation
- Nurtients in duodenum; release of CCK into the blood stream
–> CCK goes to Gall bladder to increase motility
–> CCK goes up vagal afferent to Doral vagal complex
–> vagal efferents relesase Ach to act on Gall bladder
Vagal efferents to act to release NO or VIP
• Primary bile acids (BA) entering enterohepatic circulation
synthesized from cholesterol in hepatocyte (Cholate,
Chenodeoxycholate) conjugated with _______
• Secreted across ______; Carried in bile to
gallbladder; Concentrated during digestion
taurine/glycine
canalicular membrane
• 95% BA actively absorbed from ______; 5% in colon, Bile
acid hydrolysis/dehydrogeneration performed by broad
spectrum of______ bacteria
terminal ileum
anaerobic
•______ reabsorbs BA from simisordal blood carried through
to liver through portal vein via series of transporters
• BA’s aid in digestion/absorption of fat in the intestine
Hepatocyte
• Nerves arise from vagus/sympathetic branches that
pass through____ plexus
• Preganglionic sympathetic level _____and____
celiac
T8 and T9
• Impulses from liver, gallbladder and bile ducts pass by
means of______ afferent fibers through
splanchnic nerves and mediate ______ pain
Cannot differentiate specific biliary tract site by pain
pattern per se
sympathetic
“Biliary colic”
• Two types of gallstones:
–_____ stones: Most common in Western countries
–____ stone: Bilirubin deposition
Cholesterol
Pigment
• Cholesterol gallstones: Balance between normal ratio of
cholesterol to other biliary lipids is disrupted resulting in
Cholesterol hypersecretion: Hyposecretion BA’s or phospholipids
• Diminished BA pool of enterohepatic circulation
interrupted
• Supersaturation of cholesterol not necessarily sufficient for stone formation;______ must also occur, protein secretion may be nucleating agent
Nucleation
GB epidemiology:
women >50, white
men w/ stones increase with age and higher prevalance in American Indians
Risk factors for Cholesterol Gallstones
- Increasing age
- Female sex
- Pregnancy and parity
- Exogenous estrogens
- Race
- Family history
- Obesity
- Rapid weight loss
- Physical inactivity
- Serum lipid levels
How is strict dieting assoicated with gall stones?
overweight men/women on strict diet
some pts with gastric bypasss w/in 49 months surgery
women with weight loss of 9-22 lbs over 2 year are 44% more likely to devo stones
Cirrhosis, chronic hemolysis, ileal crohn’s
disease at put pt at risk for;
black pigment stones
What is biliary sludge
Biliary Sludge (Calcium bilirubinate and cholesterol
crystals embedded in mucus gel); Precursor to stone
formation? Associated with drugs like ceftriaxone,
octreotide, thiazide diuretics, parenteral nutrition
What is the link between pregnancy and Cholelithiasis
• Incidence of biliary sludge (Precursor to gallstones)
and gallstones are 30% and 12% respectively during pregnancy and post partum
• 1 – 3% post partum woman: Cholecystectomy within first year
• Increased estrogen levels during pregnancy; Super saturated bile/sluggish GB motility
• Majority: Sludge/gallstones dissolve spontaneously after partition
Inflammation of the gallbladder causing a syndrome
of prolonged (>4 to 6 hours) steady, right epigastric
pain with fever, leukocytosis associated with
gallstone obstruction of the cystic duct.
Acute Cholelithiasis
what pts usually develop acute cholecystitis?
patients with a history of symptomatic gallstones
Pt is ill looking, feverish and tachycardic; they are lying very still and have a + murphys sign. What do you suspect of lab tests? What other tests do you order?
Patient is ill-appearing, febrile, tachycardia: lies still (Parietal Peritoneal Inflammation) seen in acute cholecystitis
Liver function test usually normal
Order ultrasonography/cholescintigraphy to confirm
How are ultrasonography and Cholescintigraphy (HIDA) used to dx acute cholecysitis
• Ultrasonography study: Detects stones; Gallbladder
wall thickening (> 4 to 5 mm) or edema. Sonographic
“Murphy’s Sign” Test sensitivity 88%; Specifity 80%
• Cholescintigraphy (HIDA scan): Technetium labeled
hepatic iminodiacetic acid (HIDA) injected IV, taken
up by hepatocyte, secreted into bile to determine
system patency – or not. Visualization in 30 to 60 minutes
What do we do to tx pt with acute cholecystitis?
- Surgical treatment Laparoscopic Cholecystectomy
- Positive Advance
- Risks/Benefits of operation
- Individuals aged 15 to 24 years: Cholecystectomy
Acute Cholangitis
• Clinical syndrome featured by ___, _____, _____ (Charcot’s Triad);
Results from stasis/infection in ______
• Severity ranges from mild to life-threatening
fever, jaundice and abdominal pain
biliary tract
In acute Cholangitis, obstruction raises______ pressure, increases
permeability of _____, permits translocation of bacteria/toxins from portal circulation or ascending from the duodenum
intrabiliary
bile ductules
Two most common causes of acute Cholangitis
Most common causes of biliary obstruction are CBD biliary calculi (28 to 70%) or benign stenosis (5 to 28%)
Common pathogens associated with Cholangitis
gram-negative bacterium:
E. coli , Klebsiella, Enterobacteria
• Major gram-positive bacterium; Enterococcus
species 10 to 20%
• Charcot’s triad occurs in only 50 to 70%
• Confusion/hypotension occur if suppurative
; Associated with significant morbidity
and mortality; Septic shock/multi-organ failure can occur
Acute Cholangitis
Lab tests for cholangitis:
Cholestatic pattern of LFT abnormalities;
Elevation of ____ and ____ and ____
(GGT) and bilirubin; Blood cultures
WBC
GGT
Serum Alk Phos
Three methods to Dx acute cholangitis
• Transabdominal ultrasonography to detect ductal dilation or stones; Small calculi difficult
• Magnetic resonance cholangiopancreatography (MRCP) helps with minute stones
• ERCP (Endoscopic retrograde cholangiopancreatography) is useful for diagnosis
and most importantly, drainage (sometimes immediately)
tool is useful for diagnosis
and most importantly, drainage (sometimes immediately)
ERCP (Endoscopic retrograde
cholangiopancreatography)
Obstructive stones in the distal CBD or at the
ampulla of vater may cause _____
acute pancreatitis
– may need to use ERCP to extract and train ducts in case of concurrent cholangitis
Clinically identifiable to acute cholecystitis but not
associated with gallstones: Usually occurs in critically ill
patients. Accounts for 10% of acute cholecystitis. High
morbidity and mortality
Acalculous Cholecystitis
Chronic progressive disorder of unknown etiology.
Characterized by inflammation, fibrosis, stricturing of
medium/large ducts in intrahepatic/extra-hepatic biliary tree
Primary Sclerosing Cholangitis (PSC)
Lots of pts with Primary Sclerosing Cholangitis (PSC) have what underlying condition?
how long do they liver after transplant?
underlying ulcerative colitis
10-12 yrs
What is on this image?
specifically what disease and where do you see sclerosis
Primary Sclerosing Cholangitis:
Periductal Sclerosis
Biliary “colic” is a misnomer; The distress is typically
______in nature; Episodic
constant
Where is biliary or GB pain located?
how is it different then cardiac pain?
Begins usually mid-epigastrium as dull, pressure-like.
Intense within 15 to 30 minutes: Severe, steady 3 to 5
hours. (Right shoulder/interscapular area)
• Unlike cardiac pain, the patient is “restless”, moves
about and re-positions in an effort to obtain relief
referred pain from GB
Right shoulder, straight back adn RUQ
The truth about biliary pain and meals
• Biliary pain often unrelated to meal time events;
may occur without clear precipitating events.
Nocturnal pain episodes (2 a.m. to 5 a.m.) are a classic feature
Misconceptions on biliary pain
• GI symptoms such as dyspepsia, heartburn,
bloating and fatty food intolerance are not
suggestive of gallbladder disease per se
• Biliary pain not a chronic continuous process
• Biliary pain not associated with eliminations
RUQ pain sight in gall bladder
• Chronic RUQ pain (often accentuated after meals) is
almost never caused by gallbladder disease
• Nonetheless: Physicians always suspect gallbladder
disease. Inevitable US study Stones = Postcholecystectomy Syndrome!!
• 22 patients with chronic RUQ pain >10 years. Balloon
inflations up/down GI tract. Pain reproduce in remote
site in ALL; reproduced in 2 sites in half of group
• Be suspicious of RUQ pain syndrome!!
Challenge with gall bladder for physicians
The most important challenge to the physician
evaluating a patient with upper GI tract symptoms
in whom gallstones are detected is whether
cholelithiasis is the cause of symptoms or an
incidental finding!
Group I: Pts with Ypical biliary symptoms/stones;
• Very likely to develop recurrent severe symptoms.
Risk of further symptoms/complications about ____
within 2 years after presentation
• Rₓ: _______
70%
Cholecystectomy
Group II. Patients with Atypical
Symptoms/Stones;
• Worrisome group: Symptom relief post-op occurs
most likely in patients with biliary pain
• 2481 patients who had elective cholecsytectomy; Symptom persistence of gas/flatulence 40%
• Patients require comprehensive search for nonstone related causes; surgery with caution
• Post-cholecystectomy syndrome in the making
III. Patients with Stones
and No Symptoms
• Gallstones are present in approximately 20% of
US adults!
• The vast majority of these people are never
bothered by this information
• Educate about gallstone symptom/disease
• No surgery
IV. Pts with typical biliary sypmtpoms without stones;
detect these pts with what test?
Gall bladder ejection fraction (GBEF) to get best diagnosis;
shold be able to eject die w/in 30 mins
