Gallbladder and Biliary Tract Flashcards
What is the function of the gallbladder?
Concentrate and store bile and deliver it to duodenum in response to meals
Bile ducts regulate storage
What is the size and location of the gallbladder?
Size of the common bile duct?
7-10 cm in length
Separation of left and right liver lobes
7-11 cm long; 5-10 mm diameter
What are the components of the gallbladder?
Fundus: Rounded blind end, contains smooth muscle
Corpus: Main storage area; contains most elastic tissue
Neck: Funnel shaped, deep in fossa (Hartmann’s Pouch) connect to cystic duct
How much bile is produced?
What increases and decreases secretion?
What is the gallbladder’s role during fasting and its capacity?
Bile produced continuously 500 ml to 1000 ml
Bile secretion increases with vagal stimulation and secretin release
Bile secretion decreases with splanchnic stimulation
Fasting state: 80% bile stored in gallbladder. Gallbladder mucosa greatest absorptive power per unit area of any body structure. Capacity: 30-50 ml; 300 ml when obstructed
What does the gallbladder due to the ion composition of bile?
Increase in sodium, bile acid anions
Decrease in chloride and bicarbonate
What is the motor function of the fasting gallbladder?
What is the motor function during the emptying?
Receptive relaxation of gall bladder to allow filling
Tonic contractions of sphincter of Oddi for pressure gradient to develop
Coordinated gallbladder contraction, SO relaxation and meal intake gallbladder empties 50 to 70% contents in 30 to 40 minutes within eating; refills 60 to 90 minutes
What is the main stimulus for emptying?
What determines sphincter motility?
CCK
Basal contractile presssure and response to CCK and MMCs
What is the gallbladder innervation pattern?
How specific is the sensory pattern?
Nerves from vagus and sympathetic plexus passing celiac plexus
Preganglionic sympathetics from T8/9
Cannot differentiate specific biliary tract site by pain pattern
How many Americans have gallstones?
20 million
What are the types of gallstones?
Cholesterol – Western countries
Pigment – Bilirubin deposition
What is the process of the formation of gallstones?
Cholesterol: Imbalance between ratio of cholesterol (hypersecretion) and BA’s or phospholipids (hyposecretion)
Supersaturation of cholesterol not necessarily sufficient
Nucleation must also occur (protein secretion)
Motility disorder resulting in long residence times can also contribute
What is the epidemiology of gallstones? (Race, Age, Sex)
Young, women
Men: Increase with age
Native Americans: 60-70% prevalence
White adults: 10-15%
Black Americans, East Asian, Sub-Saharan Africans reduced risk
What are the risk factors for choleterol gallstones?
Increasing age
Women
Pregnancy and parity
Exogenous estrogens
Race
Family history
Obesity
Rapid weight loss
Physical inactivity
What is biliary sludge?
What is it associated with?
Biliary sludge: Calcium bilirubinate and cholesterol crystals embedded in mucus gel
Associated with drugs like ceftriaxone, octreotide, thiazide, diuretics, parenteral nutrition
What is the association between obesity and gallstones?
10-25% overweight men and women on strict diet
7.8% patients post-gastric bypass
Women with weight loss 9-22 lbs/2 year period at risk