When we eat, food is broken down and nutrients are absorbed by the body. There are several important parts of the human body that have vital roles in the digestive process. The last 2 main sections that are involved in this process are the small and large intestines. But how are these body organs differentiated from one another? Read on and we’ll uncoil their distinct functions and differences.
The small intestine is the organ primarily involved in the digestion of food and absorption of nutrients and minerals in the body. It is coiled around the area of the abdomen. The small intestine is also called the small bowel. It is the longest part of the digestive system with a length of about 10 – 20 feet (3 – 6 meters) or sometimes longer depending on the age of a person or how tall a person is. The small intestine has a diameter of approximately 1 – 1.2 inches (2.5 – 3 centimeters).
Parts and functions
The small intestine has three parts: the duodenum, jejunum and the ileum. The duodenum is the shortest part of the small intestine where most of the chemical digestion takes place. It is C-shaped and measures around 10 – 15 inches (25-38 centimeters). This is the part which receives the chyme from the stomach. Chyme is the partially digested food combined with digestive secretions from the stomach. The duodenum also connects the stomach to the jejunum. The Jejunum is about two-fifths of the entire length of the small intestine. This is where you can find the longest villi. Villi are the small finger-like tissue structures found in the lining of the small intestine and they make way for increased absorption of nutrients. The ileum is the last section of the small intestine. This part is abundant with Peyer’s patches. Peyer’s patches are oval lymphoid follicles which help develop immunity from foreign particles by trapping and destroying them.
Other components and movements in the small intestine
The small intestine also has circular folds, called plicae circulares, which slow down the passage of the chyme and allows for an increased surface for better absorption. The small intestine also makes small movements in the abdominal cavity. One is called peristalsis, which is basically muscle contractions to help the digested food move along its path. Another is called segmentation, which involves contraction and relaxation of muscles to help churn the chyme and make it come into contact with the walls of the small intestine.
The large intestine is a body organ involved in the digestion of food and water and salt absorption. It is located just around or a little below the waist area and is connected at one end to the small intestine. The large intestine is also called the large bowel. It is around 5 feet (1.5 meters) long and is one-fifth the length of the gastrointestinal tract. It is called the large intestine since it has a wider diameter, measuring about 1.5 – 2.4 inches (4 – 6 centimeters).
Parts and functions
The large intestine has four main parts: the cecum, colon, rectum and the anal canal. The cecum is considered to be the beginning of the large intestine and is also connected to the appendix. It receives chyme from the ileum and is connected to the ascending colon. The colon is the final section of the digestive system, consisting of four parts, namely: the ascending colon, transverse colon, descending colon and the sigmoid colon. The colon’s function is to reabsorb fluids and to process and prepare waste products for elimination. Water is absorbed and the remaining waste material is stored as feces. The rectum stores the feces until the body feels that it is time for defecation. Defecation is the process where waste products or feces (solid, semisolid, or liquid waste) are removed by the body. The anal canal is where the feces pass through as they are discharged from the body.
Other components found in the large intestine
The large intestine also contains taeniae coli, which are three longitudinal muscles on the outside of the whole stretch of the colon. These contract lengthwise producing the haustra. The haustra are responsible for the segmented appearance of the colon. They are small pouches that are created by sac formation. The haustra also helps distinguish the colon from the small intestine when doing abdominal x-rays.
The small intestine is the longest internal organ of the body, measuring up to 20 feet (6 meters) or more with a diameter of 1 – 1.2 inches (2.5 – 3 centimeters). The large intestine is shorter measuring up to 5 feet (1.5 meters) but with a larger diameter of 1.5 – 2.4 inches (4 – 6 centimeters). Three parts make up the small intestine, whereas the large intestine has four sections. Moreover, the small intestine has plicae circulares, villi, and Peyer’s patches. The large intestine, on the other hand, lacks all those. Conversely, the small intestine does not have any taeniae coli and haustra while the large intestine which has both. In the abdominal cavity, the small intestine makes small movements compared to the large intestine which is fixed, having very little mobility.
|Small intestine||Large intestine|
|Measures 10 – 20 feet or longer||Measures 5 feet|
|Measures 1 – 1.2 inches in diameter||Measure 1.5 – 2.4 inches in diameter|
|Has three parts: duodenum, jejunum, and ileum||Has four parts: cecum, colon (ascending, transverse, descending, and sigmoid), rectum and anal canal|
|Has circular folds (plicae circulares)||Does not have circular folds|
|Villi are present||Does not have villi|
|Has Peyer’s patches||Does not have Peyer’s patches|
|Does not contain longitudinal bands (taeniae coli)||Contains taeniae coli|
|Does not have haustra||Has haustra|
|Makes small movements in the abdominal cavity||Fixed, with little mobility|
Watch this video to understand what goes on in the digestion process and determine the functions of the small and large intestines.