The Gall Bladder

Question 1

What is the gall bladder?

Answer 1

• it is a pear-shaped structure situated beneath the liver
• it is attached to the liver by connective tissue
• it’s epithelial layer is arranged in rugae
• bile enters the gall bladder from the liver through the cystic duct and exits by the same route
• secretion of bile from the gall bladder into the duodenum is controlled both neurally and hormonally
  - -> stimulation of the vagus nerve by autonomic impulses during the cephalic phase of digestion
  - -> the release of secretin and CCK when fat are present in chyme entering the duodenum
  - -> this causes the gall bladder to contract and secret bile into the small intestine
• supplied with blood from the cystic artery

Question 2

What is the function of the gall bladder?

Answer 2

• to absorb water from the bile making it more concentrated than when it was produced in the liver
• mucus is secreted into the bile which is stored until it is required

Question 3

Describe the different bile ducts

Answer 3

• the hepatic ducts leave the liver through the portal fissure and join to form the hepatic duct
• the cystic duct from the gall bladder joins the common hepatic duct to form the common bile duct
• this then joins the main pancreatic duct before it enters the duodenum through the hepato-pancreatic sphincter

Question 4

Describe the changes that occur during pregnancy

Answer 4

• progesterone affects the smooth muscle tone of the gall bladder resulting in flaccidity, increased bile volume storage and decreased emptying rate
• water reabsorption by the epithelium cells of the gall bladder is deceased so the bile is more dilute and contains less cholesterol
• there is also a tendency to retain bile salts resulting in the formation of gallstones in pregnancy
• choleostasis - bile salts deposited in skin