Large intestine

Human_colon_diagram

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The colon, commonly referred to as the large intestine, is a vital component of the human digestive system, responsible for absorbing water and electrolytes from undigested food and forming feces. It is the final section of the digestive tract and plays a crucial role in eliminating waste from the body.

Anatomy

The colon is a tubular structure that starts at the cecum (where it connects with the small intestine) and ends at the rectum. It can be divided into several sections:

• Ascending Colon: Begins at the cecum and extends upwards to the right side of the abdomen.
• Transverse Colon: The longest portion, it runs horizontally across the abdomen.
• Descending Colon: Travels down the left side of the abdomen.
• Sigmoid Colon: An S-shaped curve that connects the descending colon to the rectum.

Function

• Absorption: The primary function of the colon is to absorb water, electrolytes, and some vitamins produced by enteric bacteria.
• Feces Formation: It converts the semi-liquid chyme from the small intestine into solid feces by absorbing excess water.
• Storage and Elimination: The colon stores fecal matter until it is eliminated from the body through the rectum and anus.

Microbiota

The colon is home to a vast number of bacteria, collectively termed the gut microbiota. These bacteria aid in the digestion of food, production of essential vitamins, and play a role in the immune system. A balanced gut microbiota is crucial for optimal colon health.

Diseases and Disorders

The colon can be affected by a variety of diseases and disorders:

• Colorectal Cancer: A malignant growth that arises from the inner lining of the colon.
• Diverticulitis: Inflammation of small pouches (diverticula) that can form in the colon's walls.
• Ulcerative Colitis: An inflammatory bowel disease causing ulcers in the inner lining of the colon.
• Crohn's Disease: A type of inflammatory bowel disease that can affect any part of the gastrointestinal tract, including the colon.
• Irritable Bowel Syndrome (IBS): A functional disorder causing abdominal pain and changes in bowel habits.

Medical Procedures

Several medical procedures target the colon:

• Colonoscopy: A diagnostic procedure using a flexible camera to examine the entire colon.
• Sigmoidoscopy: Similar to a colonoscopy but only examines the sigmoid colon.
• Colostomy: A surgical procedure to create an opening (stoma) between the colon and the surface of the abdomen for the removal of feces.

Summary

The colon, or large intestine, is an essential part of the human digestive system, playing a critical role in water and electrolyte absorption and waste elimination. Understanding its structure, function, and associated diseases is vital for maintaining digestive health and overall well-being.

See Also

• Digestive System
• Small Intestine
• Gut microbiota
• Colonoscopy

Large intestine Resources
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