Intestine

Intestine begins at the stomach exit and coils through the middle of the body. The small intestine is narrow but very long, with countless folds and finger-like villi that create a huge surface area. Here, broken-down food touches the villi and slips into nearby blood vessels or lymph vessels to feed the body.

The first section, the duodenum, mixes chyme with bile and pancreatic enzymes. The jejunum and ileum continue breaking food apart and absorbing sugars, amino acids, fats, vitamins, and minerals. Muscles squeeze in segments so the food tumbles gently, giving enzymes plenty of time to work.

What remains passes into the large intestine, or colon. It is wider and shorter. bacteria living there ferment leftover fiber, making helpful short-chain fatty acids and producing vitamin K. The colon also absorbs water and electrolytes, turning the mixture into solid stool.

The final part is the rectum, which stores stool until a trip to the restroom. When the rectum stretches, nerves signal the brain that it is time to go. Strong sphincters control when stool leaves the body.

The intestines appreciate fiber-rich foods, water, and movement. These habits keep stool soft and muscles active. Washing hands, eating safe food, and getting recommended screenings such as colonoscopies protect the gut from infection or disease. Doctors can also use stool tests, blood work, or imaging to diagnose problems like celiac disease or inflammatory bowel disease.