Watch: [Understanding Your Body] Large Intestine

⭐English subtitles available⭐

 

 

There is a part of the body that makes decisions independently, without receiving signals from the brain.

It is the large intestine.

 

The large intestine, with more nerve cells than the spinal cord and peripheral nervous system, is often referred to as the 'second brain,' as it autonomously controls the digestive mechanism.

 

Therefore, a healthy large intestine ensures smooth excretion, one of the three key principles of our body's well-being.

 

This is because excretion is a vital process for maintaining bodily balance beyond waste removal.

 

The large intestine, also known as the colon, is a digestive organ that starts at the end of the small intestine and extends to the anus, resembling a long tube.

 

It is about 1.5m long, accounting for 20% of the entire intestine, and about 7.5cm wide, more than twice the thickness of the small intestine.

 

The large intestine is broadly divided into three sections: the cecum, the colon, and the rectum.

 

The first section of the large intestine, the cecum, temporarily stores the food received from the small intestine before moving it to the colon.

 

The appendix, often mistaken as the cecum, is an appendage hanging from the end of the cecum.

It is generally understood to have no significant function.

 

Inflammation in this area is commonly called cecitis, but appendicitis is the correct medical term.

 

Additionally, the cecum is involved in developing the body’s immune system, helping to regulate the colonization of beneficial bacteria during infancy.

It also plays a role in absorbing water and electrolytes.

 

The colon makes up the majority of the large intestine.

 

It is divided into four main parts based on shape and direction: the ascending colon, the transverse colon, the descending colon, and the sigmoid colon.

 

The ascending colon, which starts from the right of the cecum and extends upward towards the liver, is about 20cm long, has a large diameter, and the contents inside are more liquid than solid.

 

Next, the transverse colon runs horizontally across the upper abdomen and is close to the liver and stomach above.

It absorbs water from the intestinal contents that have passed through the cecum and the ascending colon.

 

The descending colon is located on the left side of the abdomen.

It is responsible for storing the digested food until it is solidified and expelled as feces.

 

Lastly, the sigmoid colon, also known as the S-shaped colon, is about 45cm long and curves in an S-shape before connecting to the rectum.

 

Then comes the rectum, occupying about 20cm from the end of the colon to the anus.

 

About 90% of the food digested through the cecum, colon, and rectum is transformed into liquid, with most of it absorbed, leaving a semi-solid stool.

 

Stool is gradually moved along by the peristaltic movements of the intestines and eventually expelled from the body.

 

Several nerves are involved in these peristaltic movements.

 

The nerves governing the large intestine include the enteric nervous system, the sympathetic and parasympathetic nervous systems, and the spinal sensory nerves.

 

What differentiates the gastrointestinal tract from other organs is its own enteric nervous system.

 

Thus, the large intestine can perform spontaneous movements without direct connection to the central nervous system, moving stool toward the anus through peristaltic movements.

 

Specifically, when stool contains a high amount of dietary fiber and water, it can move more easily through the intestines.

 

Therefore, consuming an adequate amount of dietary fiber and water is crucial for maintaining smooth bowel movements.

 

Adequate carbohydrate intake also helps to feed the lactobacilli in the large intestine, facilitating its active movement.

 

Bowel disorder, which nearly everyone may experience at one time or another,

with constipation being a major cause of abdominal discomfort and potentially leading to loss of appetite, nausea, abdominal pain, hemorrhoids, and more

 

While constipation can occur due to various reasons, it worsens with prolonged stool retention, lack of exercise, or an inadequate diet.

 

Therefore, it is important to adopt healthy lifestyle habits.

If you notice any abnormalities in the color of your stool or see blood after a bowel movement, it is advisable to visit a hospital for an accurate diagnosis.