Overview of the Digestive System - Digestive Disorders - MSD Manual Consumer Version (2024)

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  Digestive System

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  Human digestive system | Description, Parts, & Functions9.3: Digestive System Processes and RegulationYour Digestive System & How it Works - NIDDK23.1 Overview of the Digestive System – Anatomy & Physiology

  
  
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  The Digestive System

  
  
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  Overview of the Digestive...

  
  

• Mouth Biology of the Mouth The mouth is the entrance to both the digestive and the respiratory systems. The inside of the mouth is lined with mucous membranes. When healthy, the lining of the mouth (oral mucosa) ranges... read more

• Throat and esophagus Throat and Esophagus The throat (pharynx) lies behind and below the mouth. When food and fluids leave the mouth, they pass through the throat. Swallowing of food and fluids begins voluntarily and continues automatically... read more

• Stomach Stomach The stomach is a large, bean-shaped, hollow muscular organ consisting of four regions: Cardia Fundus Body Antrum read more

• Small intestine Small Intestine The duodenum is the first segment of the small intestine, and the stomach releases food into it. Food enters the duodenum through the pyloric sphincter in amounts that the small intestine can... read more

• Large intestine Large Intestine The large intestine consists of the Cecum and ascending (right) colon Transverse colon Descending (left) colon Sigmoid colon (which is connected to the rectum) read more

  See Also

  Chapter 11: Digestive System

• Rectum and anus Rectum and Anus The rectum is a chamber that begins at the end of the large intestine, immediately following the sigmoid colon, and ends at the anus ( Home.see also page Overview of the Anus and Rectum). Ordinarily... read more

• The pancreas Pancreas The pancreas is an organ that contains two types of glandular tissue: Pancreatic acini Islets of Langerhans (See also Overview of the Digestive System.) The acini produce digestive enzymes.... read more

• The liver Liver The wedge-shaped liver is the largest—and, in some ways, the most complex—organ in the body. It serves as the body's chemical factory, performing many vital functions, from regulating the levels... read more

• The gallbladder Gallbladder and Biliary Tract The gallbladder is a small, pear-shaped, muscular storage sac that holds bile and is interconnected to the liver by ducts known as the biliary tract. (See also Overview of the Liver and Gallbladder... read more

• The salivary glands Biology of the Mouth The mouth is the entrance to both the digestive and the respiratory systems. The inside of the mouth is lined with mucous membranes. When healthy, the lining of the mouth (oral mucosa) ranges... read more

Experts have recognized a powerful connection between the digestive system and the brain. For example, psychologic factors greatly influence contractions of the intestine, secretion of digestive enzymes, and other functions of the digestive system. Even susceptibility to infection, which leads to various digestive system disorders, is strongly influenced by the brain. In turn, the digestive system influences the brain. For example, long-standing or recurring diseases such as irritable bowel syndrome Irritable Bowel Syndrome (IBS) Irritable bowel syndrome is a disorder of the digestive tract that causes recurring abdominal pain and constipation or diarrhea. Symptoms vary but often include lower abdominal pain, bloating... read more , ulcerative colitis Ulcerative Colitis Ulcerative colitis is a chronic inflammatory bowel disease in which the large intestine (colon) becomes inflamed and ulcerated (pitted or eroded), leading to flare-ups (bouts or attacks) of... read more , and other painful diseases affect emotions, behaviors, and daily functioning. This two-way association has been called the brain-gut axis.

Aging may also affect how the digestive system functions (see Effects of Aging on the Digestive System Effects of Aging on the Digestive System Because the digestive system has a lot of reserve built into it, aging has less effect on its function than it does on the function of other organ systems. Nonetheless, aging is a factor in... read more ).