Difference Between Small Intestine And Large Intestine

The intestines are a long, continuous tube running from the stomach to the anus. Most absorption of nutrients and water happen in the intestines. The intestines include the small intestine, large intestine and rectum.

What Is Small Intestine?

The small intestine also referred to as small bowel, is an organ in the gastrointestinal tract where most of the end absorption of nutrients and minerals from food takes place.  It lies between the stomach and large intestine and receives bile and pancreatic juice through the pancreatic duct ton aid in the digestion.  

Small intestine is longer than the large intestine. It is approximately between 4.4-7.0 m long, highly convoluted and contained in the central and lower abdominal cavity. Small intestine helps to further digest food coming from the stomach. It absorbs nutrients (vitamins, minerals, carbohydrates, fats and proteins) from food so that they can be used by the body. The small intestine is part of the digestive system.

The small intestine has three parts: the duodenum, jejunum and ileum. These regions form one continuous tube and although each exhibits certain characteristic differences, there are no distinctly marked separations between them.

The first area, the duodenum is adjacent to stomach and is not supported by the mesentery. Ducts from the liver, gallbladder and pancrease enter the deudenum to provide juices that neutralize acids coming from the stomach and help digest proteins, carbohydrates and fats.

The second region, the jejunum, is the central section of the abdomen. It is deep red in color due extensive blood supply. The peristaltic movements of the jejunum are rapid and vigorous and the mesentery that supports this region has little fat.  

The third region is the ileum, which is located in the lower abdomen. Its walls are narrower and thinner than in the previous section. Blood supply in the ileum is more limited, peristaltic movements are slower and the mesentery that supports this region has more fatty areas.

What You Need To Know About Small Intestine

1. The small intestine is a part of the digestive system that runs between the stomach and large intestine.
2. Small intestine is longer than the large intestine. It is approximately between 4.4-7.0 m.
3. Small intestine is made up of three parts, that is, duodenum, jejunum and ileum.
4. The main function of small intestine is absorption of nutrients from the digested food.
5. It is narrow with a width of between 3.4 and 4.5 cm.
6. It performs the major steps of digestion and completes the process of digestion.
7. The longitudinal muscles of small intestine are arranged in circular layers.
8. Small intestine exhibits small movements in the abdominal cavity.
9. The walls of the small intestine are smooth.
10. Small intestine secretes hormones.
11. Some parts of the small intestine have the lymphoid tissue referred to as Peyer’s patches.
12. The internal surfaces of small intestine contain finger-like projections referred to as villi, which increases surface area for absorption.
13. Small intestine does not have sac-like structure referred to as Haustra.
14. Small intestine lacks epiploic appendages. Epiploic appendages are small pouches-like structures.
15. Internal surface of small intestine has circular folds referred to as ‘’palicae circulares’’

What Is Large Intestine?

Large intestine also referred to as large bowel or colon, is the last part of the gastrointestinal tract and of the digestive system in vertebrates. Water is absorbed here and the remaining waste material is stored as feces before being removed by defecation. The large intestine is wider and shorter than the small intestine. It is approximately between 4.0 and 6.0 meters.

The large intestine typically consists of four parts/sections: the cecum, colon, rectum and anus. Material passes through the ascending, transverse, descending and sigmoid portions of the colon and finally into rectum.

Also, on the surface of the large intestine, three bands of longitudinal muscle fibres referred to as taeniae coli, each about 0.2 inches wide, can be identified. They start at the base of the appendix and extend from the cecum to the rectum. Now, along the sides of the taeniae, tags of peritoneum filled with fat, referred to epiploic appendages or appendices epiploicae are found.

The primary function of the large intestine is absorption of water and electrolyte from the digestive residues (a process that usually takes between 12 and 24 hours) and storage of fecal matter until it can be expelled out.

In the large intestine, liquid and salt is removed first from the waste as it passes through the colon. Then, waste makes its way to the sigmoid, where it is stored. Once or twice per day, when the body is ready for a bowel movement, the waste is dumped into the rectum.

What You Need To Know About Large Intestine

1. The large intestine is the terminal part of the intestine that is wider and shorter than the small intestine.
2. Large intestine is shorter than small intestine. It is approximately between 4.0 to 6.0 m.
3. The large intestine is made up of four parts, that is, Colon, Cecum, rectum and anal canal.
4. The main function of large intestine is absorption of electrolyte and water.
5. It is wider with a width of between 4cm and 6 cm.
6. Digestion is not a function of the large intestine.
7. The longitudinal muscles of large intestine are arranged in three bands, strap-like structures referred to as Teniae Colie.
8. The large intestine is fixed or shows very less mobility.
9. The walls of the large intestine are sacculated.
10. Large intestine does not secrete hormones.
11. Large intestine does not have Peye’s patches.
12. The internal surfaces of the colon do not have villi.
13. Large intestine is made up of sac-like structure referred to as Haustra.
14. Epiploic appendages are present in the large intestines. Epiploic appendages are small pouches-like structures.
15. Circular folds are absent in the internal surface of colon.

Difference Between Small Intestine And Large Intestine In Tabular Form 

Similarities Between Small And Large Intestines

• Both are part of intestine (continuous tube running from the stomach to the anus).
• Both absorb substances from food.
• Both are convoluted inside the abdominal cavity.
• Both large and small intestines have longitudinal muscles.
• Both small and large intestine have goblet cells.