Gastrointestinal Tract

Gastrointestinal Tract

Latin	Tractus digestorius
Nerve	Enteric nervous system, Vagus nerve
System	Digestive system

The gastrointestinal tract (GIT), also known as the digestive tract or the alimentary canal, is an organ system within humans and other animals which takes in food, digests it to extract and absorb energy and nutrients, and expels the remaining waste as feces. The major functions of the gastrointestinal tract include ingestion, digestion, absorption, and defecation.

Structure

The gastrointestinal tract consists of several segments, each specialized in function. It begins at the mouth, continues through the pharynx, esophagus, stomach, small intestine, and large intestine, culminating in the rectum and anus.

Mouth

The mouth is the entry point for food, where digestion begins. The saliva produced here contains enzymes that start the breakdown of carbohydrates.

Esophagus

The esophagus is a muscular tube that conveys food from the mouth to the stomach using a series of muscular contractions known as peristalsis.

Stomach

The stomach is a hollow organ that holds food while it is being mixed with stomach enzymes and acids. These digestive fluids continue the process of breaking down food into a usable form.

Small Intestine

The small intestine is a long, coiled tube where most of the digestion and absorption of nutrients occurs. It is divided into three parts: the duodenum, jejunum, and ileum.

Large Intestine

The large intestine absorbs water and salts from the material that has not been digested as food, and is thus important for hydration and electrolyte balance. It includes the cecum, colon, and rectum.

Function

The primary function of the gastrointestinal tract is to break down food into nutrients, which the body uses for energy, growth, and cell repair. Food moves through the GI tract by a process called peristalsis, which is the rhythmic contraction of the muscles that line the tract.

Digestion

Digestion involves the breakdown of food into smaller components, which can be absorbed and assimilated into the body. It begins in the mouth and continues through the stomach and small intestine.

Absorption

Absorption is the process by which the nutrients from digested food are taken into the body's bloodstream. The majority of absorption occurs in the small intestine.

Excretion

The process of excreting waste products from the digestive system involves the large intestine, where water is absorbed and the remaining waste material is stored as feces before being removed by defecation.

Health and Disease

The gastrointestinal tract can be affected by numerous conditions, including gastroesophageal reflux disease (GERD), celiac disease, Crohn's disease, colitis, and cancer of the gastrointestinal tract. Maintaining gastrointestinal health is crucial for overall well-being and can be achieved through a balanced diet, regular exercise, and adequate hydration.

See also

• Digestive enzyme
• Gastrointestinal microbiota
• Human gastrointestinal tract