Role and function of the gallbladder

In life, we all know that the gallbladder is an immune organ and a digestive organ. It not only has the functions of storage, concentration, and excretion (contraction), but also plays an important role in regulating the pressure of the bile duct inside and outside the liver. The gallbladder is located under the liver. The normal gallbladder is about 8 to 12 cm long and 3 to 5 cm wide. If there is a problem with the gallbladder, we must go to a regular hospital for examination and treatment in time. In daily life, we must develop good eating habits.

1. Gallbladder's function of storing bile:

When a person is hungry (i.e. during the non-digestive period), bile is stored in the gallbladder. When digestion is needed, it is discharged from the gallbladder, so the gallbladder is called the "bile warehouse". At the same time, it also plays a role in buffering the bile duct pressure. The liver secretes 800-1000ml of bile every day, most of which is concentrated and stored in the gallbladder.

2. Gallbladder’s function of concentrating bile:

Most of the water and electrolytes in the golden alkaline liver bile are absorbed by the gallbladder mucosa and returned to the blood, leaving the effective components in the bile to be stored in the gallbladder, turning into brown or dark green weakly acidic gallbladder bile.

3. Gallbladder's function of excreting bile:

Bile excretion is regulated by humoral factors and the nervous system. 3-5 minutes after eating, the content of cholecystokinin increases. Cholecystokinin has the function of contracting the gallbladder and relaxing the lower end of the common bile duct and the sphincter of Oddi. After the gallbladder contracts, it can produce an internal pressure of 2.94Kpa, which promotes the discharge of bile to the duodenum to help the digestion and absorption of fat. While excreting bile, the bacteria in the bile duct are also excreted together with the bile. Generally speaking, the gallbladder can be emptied half an hour after eating fat. However, when cholecystitis or sphincter of Oddi is dysfunctional, bile excretion is blocked, bile stagnates, and solid components precipitate, which becomes one of the causes of polyps or stones.

4. Secretory function of gallbladder:

The gallbladder mucosa secretes about 20 ml of mucous substances per hour, mainly mucin, which can protect and lubricate the gallbladder mucosa from being dissolved by bile and make it easier for bile to pass through the cystic duct. When the cystic duct is obstructed, bilirubin in the bile is absorbed, the gallbladder mucosa secretes more mucus, and the liquid accumulated in the gallbladder is colorless and transparent, called "white bile". The gallbladder that accumulates "white bile" is called gallbladder hydrops. When the gallbladder is inflammatory and obstructed, the gallbladder can also secrete calcium.

5. The role of the gallbladder in regulating the pressure in the bile duct:

Another important function of the gallbladder is to regulate the pressure balance in the bile duct. When the liver produces 800-1000cc of bile every day and continuously discharges it into the gallbladder and extrahepatic bile duct, and maintains a certain pressure, gallbladder regulation is an important factor. When the pressure in the intrahepatic and extrahepatic bile ducts increases, the gallbladder can accommodate and concentrate more bile to maintain normal pressure balance in the bile duct. When the gallbladder is removed, the pressure balance function disappears, but the bile secreted by the liver will not decrease. Instead, all bile must be discharged into the duodenum cavity through Oddi's opening every day. At this time, the opening is narrowed and the excretion is not smooth. Over time, compensatory dilatation of the common bile duct will inevitably occur. The dilated common bile duct often changes the beak-shaped end into a rounded shape. At this time, the bile that is eager to be discharged flows into a vortex, which is one of the important theories of gallstone formation, the vortex theory. This phenomenon is very likely to form common bile duct stones. Clinical practice has also proved this point. When people receive patients with acute obstructive jaundice, they often see a history of cholecystectomy.

6. The gallbladder has important immune functions:

The gallbladder not only has the functions of storage, concentration and contraction, but also has secretion and immune functions. The gallbladder can secrete 20 ml of white liquid every day. According to scientific experiments, this liquid is immunoglobulin (IgA) secreted by the lamina propria of the gallbladder mucosa. The concentration of IgA in the gallbladder is much higher than that in the blood, which has the function of protecting the intestinal mucosa from invasion (secondary bile acid, etc.).

The gallbladder is like an important throughput lake in the Yangtze River Basin. It can efficiently absorb water to regulate bile duct pressure, protect riverside embankments, and produce and secrete immunoglobulins. Is such an organ dispensable? The conclusion is of course negative. The gallbladder is not a hotbed for the formation of gallstones. After the gallbladder is removed, the gallstones may be gone, but the patient is prone to indigestion, abdominal distension and diarrhea, bile reflux gastritis, common bile duct stones, severe common bile duct damage, susceptibility to colorectal cancer and post-cholecystectomy syndrome, etc.