SurgiSense

What is the gallbladder?

The gallbladder is a pear-shaped bag about 7–10 cm long that sits just under your liver – in the upper right part of your belly.

It is part of the hepatobiliary system, that also includes the liver and bile ducts.

Gallbladder wall

Unlike other parts of the gut, the gallbladder has a thin wall, with only three layers – it doesn’t have a submucosa.

• Mucosa (inner lining)
  It is folded so the gallbladder can stretch as it fills with bile. It also removes water and salts, making the bile more concentrated for more efficient fat digestion.
• Muscular layer
  Made of a single layer of smooth (involuntary) muscle, with fibres arranged in multiple directions, which helps to squeeze bile out efficiently when needed.
• Serosa
  Thin outer layer which keeps the gallbladder safe and anchored. It also has nerves, blood and lymph vessels that help the gallbladder do its job.

What is bile and what does it do?

Bile is an alkaline liquid, so it helps neutralise stomach acid and keeps the bowel lining safe.

The liver helps remove certain substances from the body, such as some drugs or toxins. The bile carry them out as part of the body’s natural cleanup and metabolism. It also helps get rid of excess cholesterol

Bile also helps your body digest fats and makes it easier to absorb fat-soluble vitamins like A, D, E and K.

How does the gallbladder help digestion?

The gallbladder is like a little storage tank for bile. When you eat, especially foods rich in fat and protein, your small intestine releases a hormone called cholecystokinin (CCK), which:

• Tells the gallbladder to contract and push bile through the bile duct into the small intestine.
• Signals the pancreas to release digestive enzymes.
• Tells the stomach to slow down emptying, giving the small intestine time to digest food properly.

Once bile mixes with food in the intestine, it helps break down fats into tiny droplets, making them easier for enzymes, like lipase from the pancreas, to work on. The enzymes then break the fats into fatty acids, which can be absorbed and used by your body for energy.

At the same time, bile also helps absorb substances that dissolve in fat, such as certain vitamins or medications.

Once the fats are digested and absorbed, any leftover bile helps carry waste, like excess cholesterol or bilirubin, out of the body – from your liver to your intestines and eventually out in your poop!