The large intestine is the terminal organ of the human digestive system. It consists of a caecum, colon, and rectum. The caecum is a tiny blind sac that contains symbiotic microorganisms. The caecum gives way to a slender finger-like tubular protrusion, the vermiform appendix, a vestigial organ. The caecum connects to the colon. The colon is separated into four sections: ascending, transverse, descending, and sigmoid. The descending section leads to the rectum, which leads to the anus. 

Digestive System

Here are the organs and the steps involved in the human digestive system:

• The alimentary canal comprises the mouth, the buccal cavity, the pharynx, the oesophagus, the stomach, the small intestine, the large intestine, the rectum, and the anus.
• The salivary glands, liver (including gallbladder), and pancreas are examples of auxiliary digestive glands. The teeth chew food within the mouth, while the tongue tastes it and reshapes it for adequate mastication by combining it with the saliva.
• The saliva includes salivary amylase, a starch digestion enzyme that digests starch and transforms it into maltose (disaccharide).
• The food now reaches the pharynx and arrives through the oesophagus as a bolus, subsequently moved down the oesophagus by peristalsis further into the stomach.
• Protein digestion occurs mainly in the stomach. In addition, simple sugars, alcohol, and medications are absorbed into the stomach. The chyme (food) reaches the small intestine’s duodenum. It is worked on by pancreatic juice, bile, and lastly by the enzymes in the succus entericus, completing the digestion of carbohydrates, proteins, and lipids.
• The meal is next digested in the jejunum and ileum of the small intestine. Carbohydrates are broken down and transformed into monosaccharides such as glucose. Ultimately, proteins are reduced to amino acids. Fats are broken down into fatty acids and glycerol.
• End products of digestion are absorbed into the body. These undigested particles reach the large intestine.
• The large intestine absorbs the majority of the water. Undigested food turns semi-solid in form and reaches the rectum and then the anal canal and is ejected from the anus.

Large Intestine

• The large intestine is the last organ of the human gastrointestinal (GI) tract, a continuous, tube-like route through which food travels throughout the human digestive system.
• It connects the small intestine to the anal canal, whereby food waste is excreted. In plain terms, the large intestine is responsible for creating faeces.
• The large intestine absorbs water from the residual indigestible food and compresses faeces before discharge.
• The large intestine starts in the pelvic right iliac area, just under the or at the right-side waistline, and links to the small intestine at the bottom tip.

Functions Of The Large Intestine

When food enters the large intestine from the small intestine, it has been liquified by the digestive process;  almost all nutrients have been absorbed. The colon’s function is to dry the remaining food and shape it into faeces. It accomplishes this by gently absorbing water and electrolytes as its muscle system transfers waste. Additionally, bacteria in the colon consume the waste and gradually break it down, concluding the chemical phase of the digestion process.

Parts of The Large Intestine

Caecum

The caecum is the first part of the colon. The cecum’s tip is sealed like a bag because the small intestine flows into the cecum via a tiny canal on its side (the ileocecal valve). This bag comprises the first six inches of the colon and is the most significant section of the large intestine. The caecum is the storage via which food from the small intestine enters the large intestine. When the cecum becomes filled, the colon’s muscular motions begin.

Colon

Food goes upward and sideways across the transverse colon, entering the ascending colon. These segments frame the small intestine, which is coiled within. Any leftover water and electrolytes are absorbed in the ascending and transverse colon, resulting in largely solid food waste in the descending colon. As the colon dehydrates, it secretes mucus to attach and coat the food waste, allowing it to flow more smoothly.

Rectum

It looks like faeces when the sigmoid colon transports the food waste to the rectum. Indigestible materials and dead cells released from the intestinal mucosa, combined with small proportions of mucus and water, now make up the stool. The desire to defecate is triggered when excrement enters the rectum. This is the natural continuation of the colon’s mass muscle motions.

Anus

The anus is the tube via which the waste would exit the body. A muscular sphincter closes it on each side. From the inside, the internal sphincter naturally opens to allow excrement to pass. We regulate the outer sphincter, which helps us defecate once prepared. When waste in the rectum stimulates the need to defecate, nerve impulses relax the internal sphincter.

Conclusion

The large intestine is the final segment of the digestive tract and is responsible for absorbing water and vitamins and transforming digested food into excrement. Although the big intestine is shorter than the small intestine, it is significantly thicker in diameter. As food is digested in the small intestine, the undigested food goes to the large intestine, where it is absorbed together with the residual water. The conversion of liquid chyme into faeces occurs throughout this procedure. These faeces contain food, germs, inorganic salt, unabsorbed substances, etc.