The small intestine in our digestive system, God has gifted such a marvelous body to us that each and every part of our body plays an important role in performing day-to-day activities. Each and every part of our body is very important. So the human digestive system is also very important and plays an important role in the development of the immune system, proper digestion of food, maintenance of every part of our body. So I am discussing here the role of the small intestine of our body indulge in the digestive process.
When we eat food, our teeth grind the same, salivary glands spread saliva, tongue mix saliva in food. The gastric gland in our stomach and various chemical changes occur in our duodenum, small intestine, and large intestine. Our pancreas, liver, and gall bladder also play a vital role in the digestive system.
The entire alimentary canal is lined by a mucus membrane. The lips, mouth, and esophagus are lined with stratified epithelium. And stomach, small intestine, and large intestine are composed of columnar cells, and the anal canal is also lined with stratified epithelium.
So in this way, our whole alimentary tract has been made safe by these linings. God has gifted such a marvelous body to us that each and every part of our body plays an important role in performing day-to-day activities.
Our body is incomplete in the absence of any part. Thus the role of our digestive system is essential in our life and in the development of the immune system, proper digestion of food, maintenance of every part of our body. So I am discussing here the role of the small intestine of our body indulge in the digestive process.
So I am discussing here the role of the small intestine of our body indulge in the digestive process.
The small intestine and intestinal digestion
The small intestine in our digestive system, The small intestine is about 22 feet long or about three and a half times the length of the human body and the tube of the small intestine starts from the stomach to the ileocolic valve. However, the length of the small intestine differs from man to man. It is divided into three parts, such as,
1.duodenum
Duodenum is the first and shortest part of the small intestine. Its length is about 8 to 10 inches. As soon as food reached the duodenum, it completes the first part of digestion by mixing bile, pancreatic juice to break down the food further.
2. jejunum
The jejunum is the second part of the small intestine. Its length is about eight feet long. The wall of the jejunum contains tiny hairs called villi. Villi help to absorb the nutrients available in food. The circular fold ( plicae circular) of the jejunum wall, increases the total surface area of this portion of the small intestine, helps absorb nutrients effectively.
3. ileum
The ileum is the last and longest part of the small intestine. Its length is 9 to 10 feet long. The ileum absorbs the remaining nutrients before the food moves to the large intestine. It plays a vital role in absorbing bile acid and vitamin B 12.
The bile and pancreatic duct are open in the duodenum. The small intestine is also composed of four coats like as stomach.
Also, Read – Large intestine function in the digestive system
What are the function of the small intestine?
The function of the small intestine is digestion and absorption of the chyme from the stomach. Duodenum’s contents are alkaline. Bile from the liver and pancreatic juice from the pancreas are passed into the duodenum. Bile digests the fat and neutralizes the acid of food. Pancreatic juice contains three digestive enzymes, such as,
- Amylase digest carbohydrates, cooked or uncooked.
- Lipase is fat-splitting enzyme. Break fats up in to glycerin and fatty acid.
- Trypsin digest protein. It reduces proteins and peptones to the polypeptide group.
Several enzymes available in Succus Entericus or intestinal juice complete the digestion of all foods items, such as,
- Enterokinase activates the proteolytic enzyme of pancreatic juice.
- Erepsin complete the digestion of protein , convert peptone into the various amino acids.
- Invertase acts on cane sugar.
- Lactose split into glucose.
- Maltase converts maltose into dextrose.
The absorption of digested food takes place entirely in the small intestine by capillary blood vessels and the lymphatics of the villi on the inner surface of the small intestine.
The lacteals absorbed the fat. The absorbed fat passed by many lymphatic vessels to the receptaculum chili and thoracic duct to the bloodstream. And all other digested food directly passes into capillary blood vessels of the villi, portal vein carried it to the liver for some changes.
Also, Read – pharynx function in the digestive system
The disease of small intestine
1. Intestinal Obstruction
It happens when any portion of the small or large intestine is blocked or twisted or stopped working due to any reason. Belly distension, pain, and vomiting are symptoms.
2. Carcinoid tumor
It is a benign or malignant growth in the small intestine. Skin flush or diarrhea are common symptoms.
3. Celiac disease
Due to an allergy to gluten, the small intestine does not absorb nutrients from food properly. Symptoms thereof are pain in the abdomen and weight loss.
4. Cancer of small intestine
It occurs in very rare cases. It is a benign or malignant growth in the small intestine. Symptoms are pain, fever, vomiting.
5. Diarrhea
Watery stool, frequent, loose, is commonly called diarrhea. Usually, it is due to mild infection of the colon or small intestine.
In addition to the above, there are so many other diseases of the small intestine.
Also, Read – Function of stomach in the digestive system
What are the test of small Intestine
1. Capsule endoscopy
A person swallows a capsule that contains a camera inside. The camera takes pictures of various parts of the small intestine and their images to a receiver worn on the person’s belt.
2. Endoscopy
Endoscopy is used to detect the disease of the esophagus, stomach, and duodenum.
3. Barium meal x-ray
Patients drink barium, thereafter various parts of the digestive system are seen in x-ray to detect the cause, place, and site of infection for further management.
4. Stool test
A test for blood in stool is taken. If blood is found in stool. Further colonoscopy is carried out.
Also, Read – Function of the esophagus in the digestive system
Intestine treatment
The small intestine in our digestive system, In the cases of intestinal disease, the treating physician, after examining the patient physically, carries out further tests as per the condition of the patient, detect the cause of the ailment and advise further medication accordingly. In certain cases where surgery is needed he may refer the case to the surgeon of the respective field for further management.
Also, Read – mouth function in digestive system
Frequently Asked Question About small intestine in our digestive system
Q. What are the function of the small intestine?
Ans. The main function of the small intestine is to break down food, absorb carbohydrates, fats, proteins, vitamins, minerals, and water from the same, and transport them to each and every part of the body with the help of blood. Further help gets rid of unwanted food components.
Q. What are the function of the three parts of the small intestine?
Ans. The small intestine is the longest part of our alimentary tract system. The function of three parts of the small intestine duodenum, jejunum, and ileum is to complete the digestion of food and absorb the nutrients for the use of our body.
Q. What happens to food in our small intestine?
Ans. Most of the nutrients of food are absorbed in the small intestine and our circulatory system passes the same throughout our body so that each and every part of our body takes them as per their need.
Q. What are the symptoms of infection of the small intestine?
Ans. Symptoms of infection of the small intestine,
1. Loss of appetite.
2. Abdomen pain.
3. Nausea.
4. Bloating.
5. Diarrhea.
6. Discomfort in the abdomen.
Q. What enzymes are produced by the small intestine?
Ans. Exocrine cells in the mucosa of the small intestine secrete mucus, peptidase, sucrose, maltase, lactase, lipase, and enterokinase. Endocrine cells secrete cholecystokinin and secretin.