Small Intestine helps digest food by absorbing nutrients and water. Parts of the small intestine include the duodenum, jejunum, and ileum.
The small intestine is the longest part of the alimentary canal, extending approximately 6 meters! It is a helical structure extending from the stomach to the large intestine, and is the main organ that carries out the digestive process.
The small intestine consists of three parts:
Duodenum: It is the starting point of the small intestine. It begins at the stomach's pyloric sphincter, arcs in a C-shape around the pancreatic head, and finishes at the duodenojejunal flexure. It is also where the hepatopancreatic sphincter (sphincter of Oddi) opens, which carries the bile juice.
Jejunum: The jejunum is the second part of the small intestine. It is present in the upper left quadrant of the abdomen.
Ileum: The ileum is the last and the longest part of the small intestine. It is present in the lower right part of the abdomen. The ileum terminates where the cecum of the large intestine begins. Although there is no apparent distinction between the jejunum and the ileum, there are several anatomical and histological differences:
The small intestine is divided into four layers histologically. The layers in order of internal to external layers are:
Nerves go to the small intestine from two divisions of the autonomic nervous system. Parasympathetic nerves trigger muscle contractions that transport food down the tract (peristalsis), whereas sympathetic nerves repress intestinal motions.
The small intestine has numerous unique characteristics that considerably increase its absorptive surface:
It is the passing of unformed feces regularly. Microorganisms such as E. coli, Salmonella, and Shigella are the most common causes of diarrhea.
Obstructive diseases, including paralytic ileus, hernias, and volvulus, are typical, but they can get complicated.
Infectious disorders including tapeworm, tropical sprue, and giardiasis are rare, yet they can be fatal if left untreated.
Crohn's disease, celiac disease, gastric dumping syndrome, and irritable bowel syndrome, to mention a few, are other disorders or a combination of diseases that can damage the small intestine.
1. What are the functions of the 3 parts of the small intestine?
The primary function of the small intestine is to break down the partially digested food in its smallest equivalent and then absorb them.
2. What are the symptoms of small intestine dysfunction?
Pain in the abdomen, nausea, vomiting, undigested fecal matter, excessive blood or mucus in stool, lack of hunger can be common symptoms of small intestine dysfunction.
3. What happens when the small intestine does not work properly?
The normal absorption and digestion of food will not occur if the small intestine is not working properly, leading to many deficiency disorders.
4. How can I heal my small intestine?
Eating properly cooked foods, washing fruits and vegetables before consumption, drinking clean water free from any contamination, eating natural probiotic-rich foods like curd and yogurt is good for small intestine health.
5. What will cause an infection in the small intestine?
Eating unhealthy food contaminated with disease-causing bacteria or protozoans can cause an infection in the small intestine.
6. Can a person survive without the small intestine?
Although most people can live without a stomach or large intestine, but it is nearly impossible to live without a small intestine.
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