- Gall bladder: structure and function
- The structure and operation of the body
How is the gallbladder
Gallbladder - an organ of the digestive system, having the shape of a small bag in which an accumulation of bile and increase its concentration of which is carried out periodically flow of bile into the common bile duct and duodenum.
The gallbladder is located on the inner surface of the liver between her shares. He usually has a pear-shaped, rarely conical shape. At various disorders of the gallbladder shape may change and become like an hourglass, a fishing hook.
The length of the gallbladder is in the range 5-14 cm, with an average of 6-10 cm, width up to 2, 5-4 cm, capacity - 30-70 ml. Gallbladder wall is easily extensible, it can hold up to 200 ml of fluid. As the size and capacity of the gallbladder may vary significantly in various diseases.
The gallbladder distinguish the bottom (the widest part facing anteriorly, and reaches the front edge of the liver and sometimes protruding from it), the body (the middle portion located between the bottom and the neck) and neck - neck of the gallbladder is located in the hepatic fossa and Rollovers in the cystic duct. Sometimes the cervix forms one or two protrusions. Move the body in the neck of the gallbladder occurs under acute or obtuse angle.
Identify two of the gallbladder wall: the top, adjacent to the lower surface of the liver and separated from it by a layer of loose connective tissue and a lower free facing the abdominal cavity and adjacent to the exit from the stomach and duodenum. Fundus adjoins the transverse colon (large intestine department which transversely crosses the abdominal cavity).
The structure of the fabric of the gallbladder
Gallbladder wall is composed of three layers: the mucosa (inner), muscle (middle) and connective tissue (outer). The bottom wall of the gall bladder is covered even the serous membrane. The thickness of the gallbladder wall is 1, 5-2 mm.
Gallbladder mucosa has many folds. One of them walking the spiral, in the neck, called the valve heister and together with bundles of smooth muscle fibers of the tunica forms the so-called sphincter Lyutkensa. Multiple protrusions of the mucous membrane between the muscle bundles called crypts. Between bundles of muscle fibers and connective tissue lie tubular channels not communicating with the cavity of the bladder, which is delayed infection. In these channels, sometimes there are abscesses (abscesses, encapsulated).
The muscular coat gallbladder consists of fibers arranged in different directions. Coupling shell presented dense fibrous tissue bundles consisting of elastic and collagen fibers.
How does the gall bladder
The movement of bile biliary pathways is influenced by pressure secretion produced by the liver. If this pressure is not present, the bile into the gallbladder does not arrive. The flow of bile in the gallbladder is also dependent on the degree of contraction of the muscles of the bile ducts and by muscle contraction of the gallbladder. There are three types of movements of the gallbladder:
- rhythmic movement - up to three to six times per minute in the fasting state of a person;
- worm-like (peristaltic) motion of varying intensity;
- reductions due to prolonged (tonic) contraction of the muscles that provide long pronounced increase in intravesical pressure.
Postprandial start gallbladder contraction in the bottom and the body while expanding the neck. Then comes a decrease in the total bubble, its pressure increases, and released into the bile portion of the common bile duct, after which the volume of the gallbladder is reduced dramatically. The activity of the gall bladder of a healthy person is adapted to the different conditions of the digestive system.
Gallbladder shortens if a lot of fat in the diet. If, however, a little fat, the gallbladder contracts and short-lived, reducing end before complete emptying of the stomach.
Employment gallbladder is under control of the central nervous system. When eating the central nervous system gives a command to the secretion of bile and gallbladder movement, which then increasingly intensified reflex influences from the nerve endings of the mouth, stomach and upper intestine.
Gall bladder - is not just a reservoir which drains bile, its main feature is that it regulates and maintains the constant pressure of bile in the biliary tract.