The gallbladder is a hollow organ that sits in a concavity of the liver known as the gallbladder fossa. In adults, the gallbladder measures approximately 8 cm in length and 4 cm in diameter when fully distended. It is divided into three sections: fundus, body, and neck. The neck tapers and connects to the biliary tree via the cystic duct, which then joins the common hepatic duct to become the common bile duct.

The adult human gallbladder stores about 50 millilitres (1.8 imp fl oz; 1.7 US fl oz) of bile, which is released when food containing fat enters the digestive tract, stimulating the secretion of cholecystokinin (CCK). The bile, produced in the liver, emulsifies fats in partly digested food. After being stored in the gallbladder, the bile becomes more concentrated than when it left the liver, increasing its potency and intensifying its effect on fats.

The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as the primary organ of the digestive tract. It is involved in the second phase of digestion, following mastication  (chewing). The stomach is located between the esophagus  and the small intestine. It secretes protein-digesting enzymes and strong acids to aid in food digestion, and also churns food (sent to it via oesophageal peristalsis) through smooth muscular contortions before sending partially-digested food to the small intestines.

The word stomach is derived from the Latin stomachus which is derived from the Greek word stomachos, ultimately from stoma, "mouth". The words gastro- and gastric (meaning related to the stomach) are both derived from the Greek word gaster.

Bolus (masticated food) enters the stomach through the esophagus  via the esophageal sphincter. The stomach releases proteases( protein-digesting enzymes such as pepsin) and hydrochloric acid, which kills or inhibits bacteria  and provides the acidic pH for the proteases to work.

In anatomy, the intestine is the segment of the alimentary canal extending from the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine. In humans, the small intestine is further subdivided into the duodenum, jejunum and ileum while the large intestine is subdivided into the cecum and colon.

Structure and Function

The intestinal tract can be broadly divided into two different parts, the small and large intestine. Grayish-purple in color and about 35 mm (1.5 inches) in diameter, the small intestine is the first and longest, measuring 6 meters (20 feet) long average in an adult man. Shorter and relatively stockier, the large intestine is a dark reddish color, measuring roughly 1.5 meters (5 feet) long on average. Both intestines share a general structure with the whole gut, and are composed of several layers. The lumen is the cavity where digested material passes through and from where nutrients are absorbed. Along the whole length of the gut in the glandular epithelium are goblet cells.

What Is a Hernia?
A hernia occurs when an organ or fatty tissue squeezes through a hole or a weak spot in a surrounding muscle or connective tissue called fascia. The most common types are inguinal (inner groin), incisional (resulting from an incision), femoral (outer groin), umbilical (belly button), and hiatal (upper stomach).
In an inguinal hernia, the intestine or the bladder protrudes through the abdominal wall or into the inguinal canal in the groin. About 80% of all hernias are inguinal, and most occur in men because of a natural weakness in this area. In an incisional hernia, the intestine pushes through the abdominal wall at the site of previous abdominal surgery. This type is most common in elderly or overweight people who are inactive after abdominal surgery.
A femoral hernia occurs when the intestine enters the canal carrying the femoral artery into the upper thigh. Femoral hernias are most common in women, especially those who are pregnant or obese.
In an umbilical hernia, part of the small intestine passes through the abdominal wall near the navel. Common in newborns, it also commonly afflicts obese women or those who have had many children.

The liver is a vital organ present in vertebrates  and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion. The liver is necessary for survival; there is currently no way to compensate for the absence of liver function.

This organ plays a major role in metabolism and has a number of functions in the body, including glycogen storage, decomposition of red blood cells, plasma protein synthesis, hormone production, and detoxification. It lies below the diaphragm in the thoracic region of the abdomen. It produces bile, an alkaline compound which aids in digestion, via the emulsification of lipids. It also performs and regulates a wide variety of high-volume biochemical reactions requiring highly specialized tissues, including the synthesis and breakdown of small and complex molecules, many of which are necessary for normal vital functions.

The pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as an exocrine gland, secreting pancreatic juice containing digestive  enzymes that pass to the small intestine. These enzymes help in the further breakdown of the carbohydrates, protein, and fat in the chyme.

Function
The pancreas is a dual-function gland, having features of both endocrine and exocrine glands.

The location of the parts of the colon are either in the abdominal cavity or behind it in the retroperitoneum. The colon in those areas is fixed in location.

Arterial supply to the colon comes from branches of the superior mesenteric artery (SMA) and inferior mesenteric artery (IMA). Flow between these two systems communicates via a "marginal artery" that runs parallel to the colon for its entire length. Historically, it has been believed that the arc of Riolan, or the meandering mesenteric artery (of Moskowitz), is a variable vessel connecting the proximal SMA to the proximal IMA that can be extremely important if either vessel is occluded. However, recent studies conducted with improved imaging technology have questioned the actual existence of this vessel, with some experts calling for the abolition of the terms from future medical literature.

Venous drainage usually mirrors colonic arterial supply, with the inferior mesenteric vein draining into the splenic vein, and the superior mesenteric vein joining the splenic vein to form the hepatic portal vein that then enters the liver.